i

School of GeoSciences

DISSERTATION

For the degree of

MSc in Environmental Sustainability

Student Name: Stefan Sagrott

Date: August 2011

i

Organic Farming and Local Food: Life Cycle Analysis of Breadshares

Bakery Bread

By

Stefan C. Sagrott

Dissertation presented for the MSc in Environmental Sustainability, August 2011

ii

THE UNIVERSITY OF EDINBURGH

Name of Candidate Stefan Sagrott

Address Centre for the Study of Environmental Change and Sustainability, University of Edinburgh, Crew Building, King's Buildings, West Mains Road, Edinburgh EH9 3JN

Degree MSc Environmental Sustainability Date 17th August 2011

Title of Thesis Organic Farming and Local Food: Life Cycle Analysis of Breadshares Bakery Bread

Background, aim and scope This study has aimed to calculate the carbon footprint of a loaf of bread produced under by the Breadshares Bakery. The bakery is based on an organic farm, using wheat grown on the farm, reducing transport for ingredients and is powered by a on-site wind turbine. The functional unit is defined as “one loaf (990g) of wholewheat bread consumed at home”. As well, a number of topics including food miles, energy use in agriculture and the benefits of organic farming are discussed.

Methodology The study has been carried out in accordance with the PAS 2050 methodology. Primary data compliant with PAS 2050 has been collected from the farm and bakery operations. Secondary data is sourced from LCA databases, government sources and other published works.

Results and discussion The carbon footprints calculated range from 0.39 kgCO2e per loaf of bread to 0.47 kgCO2e per loaf of bread. The main hotspots for emissions are wheat cultivation and bread consumption.

Conclusions When compared with the carbon footprints of other British breads, the Breadshares loaf is between 50% and 66% lower, highlighting the carbon savings that can be made by using organic wheat and shortening the production chain.

No. of words in the main text of Thesis 17,577

ABSTRACT OF THESIS (Regulation 3.5.13)

iii

'I hereby declare that this dissertation has been composed by me and is based on my own work’.

Stefan Sagrott

August 2011

Acknowledgements

I would like to extend my thanks to those who have provided valuable assistance and

advice at some stage during the preparation of this dissertation:

Dr. Kairsty Topp

Dr. Meriwether Wilson

Mrs Christine Wilson

Mr Roland Playle

Mr Andrew Whitley

Ms Veronica Burke

Mr Pete Ritchie

Mrs Jessica Sagrott

Any errors remain the responsibility of the author.

iv

Table of Contents

Chapter 1 Introduction 1 Section 1.1 Project & Aims of the Project 1 Section 1.2 The Environmental Impact of Mankind 3 Section 1.3 A History of Bread 15

Chapter 2 The Life Cycle Analysis of a loaf from

the Breadshares Bakery 23

Section 2.1 Life Cycle Analysis 23 Section 2.2 Methodology 27 Section 2.3 Data Sources 34 Section 2.4 Results 36

Section 2.4.1 Life Cycle Inventory 36 Section 2.4.2 Life Cycle Inventory Analysis 39 Section 2.5 Discussion 46

Chapter 3 Food, Farming and Sustainability 49 Section 3.1 Introduction 49 Section 3.2 Energy Use in Agriculture & Peak Oil 50 Section 3.3 Conventional & Organic Farming:

A Comparison 57

Section 3.4 Local Food Production, Food Miles & Sustainability Implications

66

Chapter 4 Conclusion 71

Appendix A Detailed Calculations for Life Cycle Inventory Analysis

72

Bibliography 75

v

List of Figures & Tables

Figure 1.1 Trends in human activity observed since 1750 8 Figure 1.2 Trends resulting from increased human activity since 1750 9 Table 1.1 GWP and residence time of Greenhouse Gases 10 Figure 1.3 Changes in greenhouse gas concentration 1700-present 11 Figure 1.4 Global annual mean surface temperature 12 Figure 1.5 Past global mean temperature change and predicted future

changes 13

Figure 1.6 Saddle quern 15 Figure 1.7 Reconstructed rotary quern 17 Figure 1.8 Roller milling 18 Table 1.2 Vitamin and mineral loss in white flour

with a 70% extraction rate 20

Table 2.1 Ingredients of a Breadshares Bakery loaf 29 Figure 2.1 Energy flows for ‘cradle-to-grave’ analysis of Breadshares loaf 36 Figure 2.2 Detailed energy flows for the Raw Materials stage 37 Figure 2.3 3 Detailed energy flows for Processing stage 37 Table 2.2 Emission results for the organic wheat 38 Table 2.3 Carbon footprint of each raw material 39 Table 2.4 Carbon footprint of a loaf under each scenario 40 Figure 2.4 Breakdown of the 3 carbon footprints 41 Figure 2.6 Breakdown of carbon footprint for Scenario A loaf 42 Figure 2.7 Breakdown of carbon footprint for Scenario B loaf 43 Figure 2.7 Breakdown of carbon footprint for Scenario C loaf 44 Table 2.5 Comparison of the carbon footprints of different breads in

different studies 45

Table 2.6 Relative contribution of the life cycle stages to the carbon footprint of the breads

45

Figure 3.1 Primary energy use in agriculture 1971-1995 50 Figure 3.2 Hubbert’s bell curves for global peak oil 51 Table 3.1 Studies suggesting peak oil dates 51 Figure 3.3 Energy and food prices 1992-2008 53 Table 3.2 The effects of organic farming on biodiversity, compared to

conventional farming 60

Figure 3.4 Sources of N2O and CH4 emissions in the USA 62

1

Chapter 1

1.1 Aims of the Project

This project aims to calculate the carbon footprint of a loaf of bread, baked under the

Breadshares Community Bakery scheme, from cradle-to-grave. This means that the

full lifecycle of the bread, from the raw ingredients all the way though to the disposal

stage will be evaluated for its carbon (or carbon equivalent) emissions.

Breadshares is a Community Interest Company based at Whitmuir Organic Farm in

the Scottish Borders. Established in 2011 it has the aims1 of:

• making excellent, nutritious, affordable, organic bread, biscuits, cakes and

more

• bringing bread to local markets, village halls, community meeting places and

small businesses

• giving all kinds of people the chance to learn and practise baking skills

• helping to create a more sustainable and health-enhancing local food system

• developing links between small businesses, local growers and producers in

Peeblesshire

The bread at the bakery will be made using local organic produce; with the wheat

either being grown on site or imported from farms within the local area are certified

by the Soil Association.

Bread has been the staple food for most of the world since it was first baked in the

Fertile Crescent some 10,000 years ago. In Britain, the majority of the bread

consumed in Britain during the last 50 years has been manufactured through the

Chorleywood Process, which has created a trade-off between bread quality and price,

resulting in cheap and malnourished bread, with many British people unaware of what

really goes into their daily bread. The Breadshares scheme aims to change this, on a

small scale, by teaching individuals how to make bread using the purest, most natural

ingredients possible.

1 http://www.breadshare.co.uk/

2

Of particular interest to the founders of Breadshares is the environmental impact of

modern food, with the large, centralised manufacturing and distribution hubs involved

in the supply chain. Whitmuir Farm is a certified organic farm and all produce sold in

the farm shop and produced by the Breadshares Bakery is organic. To this end, the

Bakery directors commissioned this life cycle analysis to be carried out so that the

environmental impact of the loaves could be evaluated.

The initial hypothesis is that the carbon footprint of a Breadshares loaf will be

significantly lower than that of a loaf available to purchase from any major retailer.

This is expected since wheat is grown organically and hence has no chemical inputs,

there is no transport involved, aside from within the farm and the majority of the

electricity used is generated by an on-site wind turbine.

The parameters of the study, as well as the data and results of the life cycle analysis

can be found in Chapter 2.

3

1.2 The Environmental Impact of Mankind

Over the past three centuries human activities have changed the makeup of the earth

system. Increasing globalisation, population, urbanisation and consumption have

placed greater demands on the earth’s resources than ever before. The use of these

resources, especially the burning of fossil fuels, as well as the global change of land

use, has altered the balance of gases in the atmosphere resulting in global warming

etc.

Prior to 1750 (the commonly recognised start of the Industrial Revolution), the

foundations of daily life in Britain had remained relatively unchanged from thousands

of years before (Kussmaul 1990). Britain’s population had increased gradually from

around 4 million at the start of the 17th century to 6.5 million by 1750 (Clarkson

1972:26; King & Timmins 2001:210). The majority of these people were employed in

agriculture (Clarkson 1972:10; Daunton 1995) which was, on the whole, a subsistence

activity and was still carried out using methods and practices brought to Britain

thousands of years ago. All work was carried out by manual labour (Clarkson

1972:13); ploughs were pulled by animals or humans, seeds sown by hand and crops

harvested using scythes with the produce being taken from the field by horse and cart.

Fires fuelled by wood, and to some extent by the 18th century coal, provided heat for

cooking and warming the home (Clarkson 1972:13); the smoke could be used to

preserve meats, as refrigeration in the form of ice houses was restricted to the upper

classes and light around the home was provided by foul smelling oil lamps and

candles.

The only alternative sources of energy available were wind and water power, both of

which were harnessed to turn equipment in cotton mills and millstones, grinding

wheat into flour for use in baking bread, the staple food for most of history (Daunton

1995:26).

A lack of conspicuous consumption, except by the upper class, and a fairly low

population (around 9m for the United Kingdom in the early 18th century) coupled with

the above meant that there was minimal use of environmental resources except for

4

wood and coal. Thus the ecological footprint (Rees 1992) of life at the time would

have been very low.

The Industrial Revolution as the period after 1750 is known brought about great

technological changes with knock on effects that would have a profound effect on not

just Britain but the world. Early technological advances such as Jethro Tull’s seed

drill, which mechanically sowed seeds and turned over the furrow, and the

introduction of the four field rotation system (Ashton 1977:21-22) lead to improved

yields in both quality and quantity (Daunton 1995:40). The introduction and

subsequent widespread adoption of the iron plough and Meikle’s threshing machine

reduced the size of the workforce required for agriculture. The upshot of this was that

the yield per worker from agriculture increased, as yields went up and the number of

workers decreased. More food was available not only to feed a growing population,

but also for export and the redundancies brought about by the introduction of

machinery would provide for the burgeoning industrial workforce (Daunton 1995:39).

The two drivers that sparked the industrial revolution were the invention of the steam

engine (Ashton 1977:55-58) and the widespread adoption of coal as a fuel; this

allowed the manufacture of purer iron (both wrought and cast) in greater quantities.

The steam engine made two major changes in the fabric of British industry. Firstly it

allowed for the centralisation of manufacturing processes into one factory.

Traditionally work such as spinning and weaving had been part of a cottage industry

carried out in the home, although larger scale production centres did exist. Steam

engines allowed not only for the work to be undertaken in one place, but that the

factory could be sited away from the type of water sources required for mills (fast

flowing and steady supply), opening up vast areas of the country as manufacturing

areas.

The advent of quicker and cheaper iron production allowed Britain to move away

from importing iron from Russia (Ashton 1977:54), and it was not before long that

iron replaced wood and stone as a building material and was used in every walk of

life; agriculture, engineering, transportation, and textiles (Ashton 1977:55).

5

It was around this time that the first musings on environmental limits were put to

paper; in 1798 Thomas Malthus, a preacher from Surrey, published the first edition of

his work An Essay on the Principle of Population. The premise of the works was

Malthus’ theory that whilst population would increase exponentially, food production

could only grow geometrically; meaning that at some point population growth would

outstretch food production resulting in famine. This famine, Malthus suggested,

would reduce the population to a level that could be supported by the food

availability.

A Malthusian situation has not yet occurred despite a tenfold increase in Britain’s

population due to technological advances that have increased yields (c.f the green

revolution) and the ability to import food from abroad.

Once the basis of the Industrial Revolution had been established it allowed for a

whole magnitude of scientific discoveries and inventions. Civil engineering projects

such as canals and bridges were undertaken, and expansion took place in every walk

of life. Urbanisation increased as factory workers moved to cities to live closer to

their workplaces and manufacturing & industrial outputs increased. Railways,

powered by coal, allowed for the mass transport of people and goods over great

distances. As the pace of the Industrial Revolution increased, more resources were

required and this period represents the first time that resources were exploited on a

large scale and in a systematic way (although it should be noted that resource use,

namely metal smelting, by the Romans and Greeks during the 1st Millennia BC and

AD has been detected in Greenland ice cores); and is a trend which continues on a

even greater scale to this day. Between 1800 and 1900 the consumption of coal in

Britain increased from 10 million tons to 167 million tons per annum (Clapp

1994:16).

It stands to order that the use of any resource produces waste and Victorian Britain

was no different. With the adoption of coal as the fuel of choice and much of the new

industry involved burning coal, smelting metals and so forth, it is hardly surprising

that air pollution in urban areas became a big issue. It has been estimated that by the

early 20th century Sheffield was receiving deposits of 55 tons of solids per square mile

every month (Clapp 1994:14). It must be noted that prior to the 1970s most cases of

6

pollution were thought of as isolated, local issues rather than as part of a larger system

with the capacity to have impacts across the entire planet (Clapp 1994:57).

As the use of coal expanded into other fossil fuels such as oil and gas, it increased

mankind’s capacity to “extract, consume & produce” (Grübler 1998), although the

19th century had experienced a 5 fold increase in energy use, that was a mere drop in

the ocean compared to the 16 fold increase in energy use during the 20th century.

This new capacity caused not only an enormous growth in population from 1bn in

1800 to 6bn in 1999 (with a projected rise to 9bn by 2050) (Steffen et al 2005:81) but

also allowed for natural resources to be discovered, extracted and used quickly, and in

large amounts.

Increases in population, as well as the subsequent economic increases and

improvements, which have raised both life expectancy and lifestyle expectancy, have

placed an increasing demand on the whole spectrum of Earth’s resources (Steffen et

al 2005:81); the impact of such a relationship is demonstrated by the IPAT equation:

I = P x A x T

Where I = impact, P = population, A = affluence and T = technology (Ehrlich &

Holdren 1971)

Whilst not particularly useful over short time scales, the equation can provide

interesting data, and thus an insight into the impact of human activity over a time

scale of decades or even greater (Steffen et al 2005:84).

It can be said that we are living far more comfortable lives than at any other point in

human history, in the developed world at least, however there is a significant

environmental cost associated with this.

Virtually no part of the planet remains untouched by development; there has been

mass land use change, biotic additions & losses, a loss of biodiversity and mass

extraction of minerals from increasingly remote and fragile locations. The rate of

7

tropical deforestation has been as high as 4% per year (Steffen et al 2005:98) and it

has been calculated that we have cut down more than a third of the world’s trees.

Biodiversity has been thinned by human activity; current rates of extinction are 100 to

1000 times greater than in pre-human times (Pimm et al 1995). Up to 20% of all birds

and 39% of all mammals & reptiles are threatened by extinction and between 22-47%

of all plant species are in danger of becoming extinct (Pitman & Jorgensen 2002;

Steffen et al 2005:118). Humans have made wholesale changes to natural habitats by

introducing non-native species to areas; 20% of plant species in continental areas are

non-indigenous, rising to 50% or higher on many islands (Rejmanek & Randall 1994).

The ecological footprint (i.e. humankinds demand on resources) is now 2.5 times

greater than what it was before the industrial revolution, and we have crossed the one

planet boundary, meaning that we are living beyond our means, beyond what the

planet can naturally support.

This period from 1750 has been deemed ‘The Great Acceleration’ by a number of

researchers, as progress and development have increased at such a rapid rate (Steffen

et al 2005). Figure 1.1 below shows a selection of the major trends in human activity

observed since the start of the Industrial Revolution and Figure 1.2 shows trends

resulting from human activity.

8

Figure 1.1 Trends in human activity observed since 1750 (From Steffen et al 2005:132)

9

Figure 1.2 Trends resulting from increased human activity since 1750 (Steffen et al 2005:133)

The loss of biodiversity is not only a concern relating to a decline in species but can

also be linked to wider issues. The natural world provides many processes that are

beneficial, or even critical, to mankind. Such processes include nutrient cycling,

purification of air & water, generation of soil and pollination of crops & vegetation.

The Millennium Ecosystem Assessment (2005) calculated that the value of ecosystem

services in 1997 to be in the region of $33 trillion per year. This is best highlighted by

a case study from Maoxian County, China. Here the decline in bee numbers,

10

attributed to increasing human activity, especially the use of pesticides, has resulted in

farmers having to pollinate apple trees by hand. 20-25 people are required to perform

the work of two bee colonies (Steffen et al 2005:248-9) bringing about an additional

expense for the apple growers.

Another consequence of increasing global development are the changes to the planet’s

atmosphere. Through the use of CFC’s mankind has already altered the atmosphere

by depleting the ozone layer (Middleton 1999:148) and this prompted a quickly

implanted ban on the use of CFC’s. In addition there is also the rather well known

issue of global warming. Deforestation and the combustion of fossil fuels have

released greater amounts of carbon dioxide (CO2) into the atmosphere than ever

before (NAS 2008:7). Carbon dioxide, along with the other greenhouse gases (GHG)

of water vapour, methane, nitrous oxide and ozone, cause positive radiative forcing

(IPCC 2001:5); whereby thermal radiation emitted either by the earth or entering the

atmosphere from the sun are trapped by the gases, increasing the global temperature.

The other greenhouse gases are measured in relation to their global warming potential

(GWP)2. Carbon dioxide is the baseline figure and has a GWP of 1. Methane (CH4)

has a GWP of 25 and has risen from a concentration of 670ppb in pre-industrial times

to 1700ppb presently (Steffen et al 2005:101), with the majority of methane emissions

coming from agriculture and the decomposition of organic materials.

Greenhouse Gas Residence time (years) GWP (100 year horizon) Carbon Dioxide 5-200 1 Methane 12 25 Nitrous Oxide 114 298 HFC-23 260 14,800 HFC-134a 13.8 3,380 Sulphur hexaflouride 3200 22,800

Table 1.1: GWP and residence time of Greenhouse Gases

Nitrous Oxide (N2O) has a GWP of 298 and its atmospheric concentration has

increased from 285ppbv to 310ppbv (Steffen et al 2005:103), with around a third of

N2O emissions being anthropogenic (mainly agriculture) (IPCC 2007:7).

2 GWP in 100 year time horizon

11

Currently carbon dioxide emissions stand at 26.5 GtCO2 per year (IPCC 2007:2) of

which three quarters is attributed to fossil fuel burning, with the rest being caused by

changes in land use, especially deforestation (IPCC 2001:7).

Figure 1.3: Changes in greenhouse gas concentration 1700-present (Steffen et al 2005:103)

Since 1750 the global atmospheric concentrations of CO2 have increased from

280ppm to 379ppm in 2005 (IPCC 2007:2) and is currently at the highest

concentration for 650,000 years (IPCC 2007:2; NAS 2008:2). At the same time,

global average surface temperature has increased by 0.6ºC (IPCC 2001:5) (Figure

1.4). The IPCC 4th Assessment (2007) concluded that by 2100 global temperatures

will have likely risen by 1.1ºC-6.4ºC (IPCC 2007; NAS 2008:8), although as these are

only model predictions, uncertainties remain (Figure 1.5).

12

Figure 1.4: Global annual mean surface temperature (Steffen et al 2005:129)

The increase in global temperatures has had a number of impacts around the world

(Steffen et al 2005:203,249); a decline in mountain glaciers (e.g. Kilimanjaro) and

global snow cover has been observed and these have contributed to global sea level

rise (a rate of 1.8mm/year between 1961-2003) (IPCC 2007:5-7) and further increase

in temperature are likely to see sea level rises between 0.18m and 0.59m (NAS

2008:8). Any future sea level rise will have large effects on many low lying island and

coastal regions world wide; islands such as the Maldives, the Marshall islands, Tuvalu

13

as well as cities such as Venice, Tokyo and Bangkok which are all at risk of flooding

(Middleton 1999:157). Changes in polar ice have been observed and although these

do not contribute to sea level rise they can be linked to habitat loss and albedo change.

Other effects include changes in ecosystems (including species extinction and changes

in animal & bird migration) and changes in global and regional climate & weather

systems, which could lead to increases in extreme climatic events such as droughts

(Middleton 1999:155).

Figure 1.5 Past global mean temperature change and predicted

future changes (Steffen et al 2005:149)

Of particular concern to this project is the issue of food security. Most reports suggest

that the impacts of global warming will vary between regions; with a generalised

sweep that crop yields in low latitudes will decrease, whilst yields in high latitude

areas will increase. Europe could see a 25% increase in yields (Steffen et al 2005:217)

whilst areas such as Pakistan could see up to a 50% decrease in yields (IPCC

2007:14). Those who will be hit hardest by climate change are those who can ill

afford it.

Agriculture is currently a large contributor to global GHG emissions. Fossil fuels are

intensively used in making agro-chemicals (especially through the Haber-Bosch

process) as well as being used to power machinery and other equipment. Growing

crops, especially legumes and the use of N-based fertilisers, as well as changes in land

14

use and emissions from agricultural soils have lead to increasing amounts of N2O in

the atmosphere; whilst the decomposition of crop wastes and emissions from cattle

have added extra CH4. Although it should also be remembered that crops and plants

can act as sinks for CO2, removing it from the atmosphere.

As wider concepts of sustainability and sustainable development have emerged,

agriculture has been a sector targeted for a reduction in emissions. Organic farming

has the potential to significantly reduce emissions, as it does not use any chemical

inputs to the field, however in some circumstances this can potentially lead to

increased emission as more machine hours are required to carry out the work. The

case for organic vs. conventional farming, as well as other issues relating to food,

farming and sustainability are examined in Chapter 4.

15

1.3 A History of Bread

The first real indications of bread come from the Neolithic period some 10,000 years

ago; although recently some scant evidence for the use of grinders and pounders on

dry seeds dating to the Epipaleolithic may point towards an early form of flour, and

perhaps bread (Watkins 2005:209). Starting in the Fertile Crescent (modern day Iraq,

Syria, Jordan, Lebanon, Israel and Iran) and gradually spreading out across Europe,

arriving in Britain around 4000 BC (Whittle 1999) farming allowed the inhabitants of

Britain to adopt a sedentary lifestyle; growing crops and domesticating animals.

Saddle querns (Figure 1.6) dating back to this period have been found in Britain, and

would have been used to grind cereals into flour. Despite this, no-one is precisely able

to say when bread was first baked, and its discovery was most likely accidental!

The earliest breads we know of, from the Middle East, were unleavened flat breads

baked on heated flat stones or straight in the embers of a fire (Marchant et al

2008:16). Dough left alone, naturally rises and again it is not known when the switch

from unleavened bread to leavened bread took place. Preserved loaves of bread, along

with tools and cereal remains have been excavated from the Neolithic lake villages in

Switzerland (Ashton 1904:13; Marchant et al 2008:16).

Figure 1.6: Saddle quern (National Museum of Wales)

Archaeological evidence shows that around the world, breads were made depending

on the cereals available in different regions; wheat was used in the Middle East, North

Africa, Europe, southeast Asia and India; rice was used in East Asia, maize in the

Americas and soghum in sub-Saharan Africa (Scarre 2005:191).

16

Of the wheat used in Europe, different varieties were available; einkorn, emmer, spelt

club and durum were used in varying regions, each suited to different climates and

soils, with the varieties providing different properties for use in bread making

(Marchant et al 2008).

In prehistoric Britain, emmer and spelt were the most popular varieties of wheat

(Reynolds 1978:58), and both have made a recent resurgence with flour made from

both species available to be bought in many shops3. Technological developments such

as the introduction of metals improved the efficiency or agriculture; bronze then iron

was used as scythe blades, iron was used instead of stone for ard shares and also

allowed for the development of the rotary quern, the forebearer to millstones, which

greatly increased the efficiency of grinding wheat into flour (Marchant et al 2008:18-

19). Archaeological discoveries such as large pits and four poster structures have been

interpreted as early granaries (Reynolds 1978) and suggest that Iron Age Britons were

storing grain for winter. A wooden butter dish found at Oakbank Crannog, Loch Tay

may indicate that bread in the past was consumed in a similar manner to modern day,

with butter spread on it (Dixon 2004:150).

When the Romans invaded Britain they brought with them the watermill. (Marchant

et al 2008:41) as well as specialised bread ovens. Excavated examples of these are

known across Britain, usually associated with Roman settlements and temporary

marching camps (Cook & Dunbar 2008; Marchant et al 2008:41). After the Romans

withdrew from Britain and the country entered into the period known as the Dark

Ages it appears that the technological progress was lost. Indeed it wasn’t until the end

of the First Millennia AD that the watermill re-appeared, but by the time of the

Doomsday Book in 1086 there were over 6000 of them (Marchant et al 2008:42).

It was around this time too that windmills first appeared in the British countryside.

Legend has it that they were brought to Europe by Crusaders returning from the Holy

Land (Ashton 1904:103), although there is no evidence to support this. Either way by

3 http://www.shipton-mill.com/flour-direct-shop/speciality-and-rare-flours/shop-47/organic-emmer-wholemeal-414 & http://www.dovesfarm.co.uk/flour-and-ingredients/organic-flour/organic-white-spelt-flour-x-1kg/

17

the year 1300 there were over 4000 operating in England (mainly in the East)

(Marchant et al 2008:44).

Figure 1.7: Reconstructed rotary quern4

Aside from design changes in windmills, the development of dedicated bakeries &

bread ovens and the introduction of various laws, taxes and guilds very little changed

in the bread industry until the Industrial Revolution (Ashton 1904; Marchant et al

2008).

For most of its history, bread has been a status symbol. In ancient Rome, rye bread

was desirable and eaten by the wealthy, whereas having to eat barley bread was seen

as a punishment (Marchant et al 2008:24-5). Until the 20th century in Britain, white

bread was eaten by high society and brown bread by the poor (Marchant et al

2008:29-31, 134); as white bread had undergone more processing and was easier to

chew, it was seen as a luxury item. Conversely brown bread was rougher, cheaper and

harder on the teeth.

4 https://picasaweb.google.com/BodgitandBendit/ReplicatedArtifacts#5020729258135659842

18

Flour and bread making was a quick adopter of the new technology introduced during

the Industrial Revolution (Marchant et al 2008:51). Steam power gradually replaced

water and wind, reducing the industry’s reliance on nature (and thus removing the

location advantage of some areas of the country) and allowing for greater flour yields

(Marchant et al 2008:64-5). Other technological developments included higher

capacity & greater efficiency ovens, mechanical mixing, slicing and wrapping

machines (Marchant et al 2008), with arguably the biggest development being the

introduction of roller milling, although it has been argued that this was also a large

step backwards for nutrition (Marchant et al 2008; Whitley 2009: Alexander

2010:128).

Figure 1.8 Roller milling5

Roller milling works by passing the wheat through pairs of revolving steel rollers,

with the gap between each roller getting successively smaller and smaller (Ashton

1904; Marchant et al 2008; Alexander 2010). After each roller, sieves separate the

different sized particles, allowing them to be put back through the system, reducing

them to fine flour (Ashton 1904:111). Since the rollers could exert more pressure on

the wheat, they could handle the harder wheat’s of Canada and the USA opening up

export markets that flooded the UK with cheaper wheat.

Rather than grinding like a typical pair of millstones, the roller mils scrape and peel

the endosperm from the bran, which is then discarded for other uses (Gélinas et al

2009:525). The main problem with this is that the endosperm contains many of the

vitamins and nutrients found in wheat, and thus the peeling and discarding of it,

removes these nutrients from the flour. Estimates suggest that up to 80% of the 5 Image from: http://www.dovesfarm.co.uk/about/the-history-of-bread/the-history-of-bread-the-industrial-revolution/

19

original vitamins are removed from the resulting white flour (Table 1.2) (Whitley

2009; Alexander 2010:182). The increase in pellagra (a Vitamin B deficiency) in the

United States during the early 20th century has been linked with the adoption of roller

mills (Alexander 2010:183).

The roller milling method proved so successful in destroying the nutritional value of

bread, that by 1911 it had become a national controversy, and became a major selling

point for brown and wholemeal bread. During WWII a number of changes were made

to bread to increase its nutritional value; first extraction rates of the flour were raised

meaning that more of the nutrients made it into the flour; secondly the use of

bleaching agents to make flour whiter was prohibited; thirdly vitamins such as

calcium, thiamine, niacin and iron were added into white flour (a practice which

continues to this day) (Whitley 2009:25).

It was during the 20th century that the long standing status quo changed; white bread

became the norm, whereas brown & wholemeal breads became a luxury item

(Marchant et al 2008; Gélinas et al 2009). The innovations discussed, led to a drop in

the price of bread but this was accompanied by a drop in consumption levels as well.

By the end of WWII British baking had become dominated by three main companies:

Rank-Hovis-McDougall, Spiller-French and Allied Mills. With the end of rationing,

the price of bread rose, and consumption dropped further.

The development that has had the greatest effect on bread, and is responsible for the

light, fluffy, soft crusted and tasteless bread on sale today is the Chorleywood Bread

Process (CBP) (Lawrence 2004; Marchant et al 2008; Whitley 2009).

Introduced in the early 1960s by the British Baking Industries Research Association

(Lawrence 2004; Marchant et al 2008), CBP allowed soft British wheat, with a lower

protein content (Whitley 2009:7) that is not usually suitable for baking to be used in

bread production (Marchant et al 2008:164). By incorporating air and water into the

dough at high speeds, and by using at least double the quantity of yeast (Lawrence

2004:106) it was possible to produce bread in 40% of the time required for traditional

bread (Marchant et al 2008:167).

20

Nutrient Loss (%)Thiamine (B1) 77 Riboflavin (B2) 80

Niacin 81 Pyridoxine (B6) 72 Pantothenic Acid 50

Vitamin E 86 Calcium 60

Phosphorous 71 Magnesium 84 Potassium 77 Sodium 78

Chromium 40 Manganese 86

Iron 76 Cobalt 89 Zinc 87

Copper 68 Selenium 16

Molybdenum 48 Table 1.2: Vitamin and mineral loss in white flour

with a 70% extraction rate (Whitley 2009:23)

The Chorleywood method is only successful if additives are used to make the bread

(Lawrence 2004:106, 108-9; Whitley 2009:7-13); hard fat with a high melting point is

required to give the bread structure, emulsifiers provide volume to the bread, as does

L-ascorbic acid by increasing gas retention. Various preservatives are added to

increase shelf-life and numerous enzymes are added to carry out various functions,

but since they are destroyed during the baking process they do not have to be declared

on the label.

Due to the short fermentation time, flavour is unable to develop and extra salt has to

be added (around 0.5g per 100g of sliced white bread) to compensate (Lawrence

2004:108). Extra water is added to increase volume to the extent that the average loaf

made via CBP is 45% water.

The Chorleywood Bread Process is also incredibly energy intensive. Prior to the

industrial revolution, bread was completely hand made and then baked in open fires

(also used for cooking and heating) or wood-fired ovens. The Industrial Revolution

introduced machinery to the baking process, powered by coal, gas and then electricity.

The CBP is a wholly mechanised system, where ingredients weighing over 300kg are

21

fed into mixers, which turn them into dough in three minutes. The dough is then

placed on a conveyor that transports it through machinery that shapes, divides, proves,

and bakes the bread for 54 minutes (where it is constantly moving pass gas burners)

before being cooled for 110 minutes (the most energy intensive process).The bread is

then sliced, and wrapped ready for distribution across the entire UK (Lawrence

2004:112-113).

The end result of all this is that, despite the wide range of breads available in the UK:

sourdoughs, rye breads, ciabatta, baguettes, pizza dough, wholemeal, pitta bread,

flatbreads (Whitley 2009) 80% of the UK’s bread is made using the Chorleywood

process. One factory in England produces 10% of all the bread, turning 820 tonnes of

flour into 1.5million loaves a week (Lawrence 2004:111). Bread can now be bought

for as cheaply as twenty pence a loaf and it has been suggested that there are a

number of health issues, including thrush, celiac disease, wheat & yeast intolerance

(Whitley 2009:4) caused by Chorleywood made bread6.

To this end Andrew Whitley, a baker, and former owner of the Village Bakery in

Melmerby started the Real Bread Campaign7 with the aim to “bring real bread back

into the hearts of local communities” and make it:

• better for us

• better for our communities

• better for our planet

Andrew is now the mentor for the Breadshares Scheme, which has aims very closely

linked to those of the Real Bread Campaign.

The availability of cheap, long lasting bread from supermarkets and other high street

stores, where it is often sold as a loss leader (Lawrence 2004; Whitley 2009) was the

last nail in the coffin of community artisan bakers. At the start of the 20th century

there were 12,000 registered master bakers in the United Kingdom but by 1995 there

were only 3,000 (Marchant et al 2008:220).Unable to compete with the supermarkets,

these statistics reflects a wider trend observed on the high street in recent years

(Lawrence 2004:123). The decline of the British high street has been linked with a 6 For a further discussion of these see Whitley (2009) Chapter Two. 7 http://www.sustainweb.org/realbread/

22

reduction in community spirit and social cohesion. Whitley (2009:243) sees the eating

of bread bought from a local baker as providing “a more profound sense of

connectedness with the community and the natural world that sustains it”.

However, since 1995, 500 new master bakers have registered in Britain and their

popularity can be seen in many affluent areas, with people queuing out of the doors

early on a Saturday morning. Some have argued that this past-time is now an “organic

living, middle class cliché” (Siegle 2011) rather than a wider reflection of British

society.

Home baking has also regained popularity, with an increase in the sales of

breadmakers and breadmaking books. In 2008 the homebaking market in the UK was

worth £491 million (Marchant et al 2008:222).

Perhaps all is not lost for the humble loaf.

23

Chapter 2: The Life Cycle Analysis of a loaf from the Breadshares

Bakery

2.1 Life Cycle Analysis

Life cycle analysis (LCA) is increasingly being used by companies to examine the

environmental impacts of products and services they provide (Nissinen et al

2007:538; Espinoza-Orias et al 2011:352).

It is a method of calculating the greenhouse gas emissions (GHG) generated during

the product’s lifetime (known as the cradle-to-grave approach) and is more commonly

referred to as ‘carbon footprinting’ (BSI 2008b:1-2).

The data generated by an LCA can be used internally and externally by a company.

Internally the data can be used to (ISO 2006; BSI 2008a, 2008b):

• Identify cost savings

• Carry out carbon accounting and thus;

• Reduce GHG emissions across the company

• Incorporate lessening environmental impacts into product design and company

strategy

• Move to a more environmentally friendly supply chain

Externally the data can be used to (ISO 2006; BSI 2008a, 2008b):

• Demonstrate corporate responsibility

• Inform customers & investors on product impacts

o Eco-label/market products

• Meet demands from ‘green’ consumers

• Promote sustainable consumption (Nissinen et al 2007:538)

Carbon footprinting allows consumers to connect the products they buy with

environmental problems that occur in distant places and times (Nissinen et al

2007:538) empowering the consumer to make more responsible decisions.

24

A number of criticisms have been directed at the LCA method recently, mainly due to

their inaccessible nature: “LCA reports are extremely technical, featuring long lists of

environmental pollutants and abounding with technical terms. They are not directed

at lay people who need to get a quick overview” (Nissinen et al 2007:538). At the

other end of the scale LCA results can be oversimplified for the consumer, with the

results often being converted into equivalents for comparison, such as equal to driving

a medium sized car for x miles, distancing the project from the environmental

information trying to be put across.

Studies such as Nissinen et al (2007) have attempted to develop and evaluate

benchmarks for life cycle assessment based environmental data, with the conclusion

that a scale based system against which different products can be plotted is the most

favourable amongst tested consumers.

Recently the carbon footprint of foods has become a burgeoning topic and this is

reflected in the literature. As consumers have become more environmentally aware

and started to take an active approach in purchasing sustainable products, it is hardly

surprising that manufacturers have sought to evaluate and place carbon footprint

labels on produce.

Produce perceived as being more sustainable and environmentally friendly such as

organic foods have been becoming increasingly popular. In 2009 the organic produce

market in the UK was worth £1.84bn (Soil Association 2010:4) and it is estimated

that the market will expand by 2.5% in 20108 (Soil Association 2010:4). On the whole

ideas relating to local and sustainable produce appear to be coming to the fore with

88.3% of households purchasing some form of organic produce (Soil Associaton

2010:4). Organic vegetable box schemes are increasingly popular, in 2009 sales of

them totalled £154.2 million (Edinburgh alone is served by 6 different schemes) and

farmers markets selling fresh, local, produce remain popular (although experienced a

decline during the recession) (Soil Association 2010:13). One study found that

motivations for purchasing organic produce included (Soil Association 2010:8-9):

• A preference for natural/un-processed food

8 Actual figures for 2010 are not yet available.

25

• Restricted use of pesticides

• Better taste

• ‘Better for my well-being’

• Better for the planet

Bread, as previously discussed, is a staple food that most people eat daily (99% of UK

households purchase bread (Espinoza-Orias et al 2011:352)) and the dominant baking

process in the UK is incredibly energy intensive. Arguably the greatest environmental

burden of making bread is the agricultural processes involved in growing the wheat

(Braschkat et al x:12) as this results in the emissions of CO2, N2O and CH4. There is

also the combustion of fossil fuels to power machinery, and in conventional farming

the application of fossil-fuel intensive agro-chemicals.

A number of studies into the carbon footprint of bread have been made, with the

majority focussed on bread making in mainland Europe or North America (Andersson

& Ohlsson 1999; Hansson & Mattsson 1999; Andersson 2000; Braschkat et al 2010

Meisterling et al 2009). Whilst they provide some useful insights into carrying out an

LCA for bread, they are not of direct relevance to this study as they differ in both

farming methods and bread type.

Of direct relevance are a number of studies into British bread (Berners-Lee 2010;

Allied Bakeries 2009; Espinoza-Orias et al 2011) which provide data on the most

regularly consumed bread, allowing for comparisons with bread from the Breadshares

project. Of the most useful is the latter study, as it has examined a number of different

bread scenarios as well as describing the methodology of the study, which provides

the potential for this study to be directly comparable with that carried out by

Espinoza-Orias et al (2011).

In Britain, there are two methodologies for carrying out life cycle assessments. ISO

14044 (2006) is the international standard for LCA’s and governs their application

worldwide. The methodology specific to Britain is the Publicly Available

Specification 2050 “specification for the assessment of the life cycle greenhouse gas

emissions of goods and services” (BSI 2008a, 2008b) created by British Standards

26

Institute and builds on the assessment methods established by ISO 14044 (BSI

2008b:iv).

There are four stages to carrying out a full life cycle assessment (ISO 2006:6):

1. Goal and scope

2. Inventory analysis (LCI)

3. Impact assessment (LCIA)

4. Interpretation of results

ISO 14044 requires that the goal and scope is clearly defined and consistent with the

intended application, although it does allow for refinement during the study (ISO

2006:7). The reasons for carrying out the study, the intended audience of the study

and the use of the results are all required to be defined in the goal (ISO 2006:7), and

for the scope, the system boundary and functional unit, as well as data sources must

be set out (ISO 2006:8-11).

The creation of the inventory analysis requires the accounting for all flows to and

from the product, as defined within the system boundary, and these flows can include

raw materials, energy, greenhouse gas emissions and so forth (ISO 2006:12). This

normally involves the creation of flow charts and data tables, as well as interviewing

external members of the supply chain.

The impact assessment stage involves the evaluation of the environmental impacts of

each of the flows as defined in the inventory analysis (ISO 2006:16-23), with the

impacts being converted in the common equivalence units (e.g. CO2 equivalent).

These are then added together to provide the overall LCA total, or carbon footprint

(ISO 2006).

The interpretation stage normally includes identifying significant issues arising from

the results of the LCI and LCIA stages, as well as evaluating the results for

completeness and consistency. Finally it should include conclusions, limitations and

recommendations based on the results of the LCA (ISO 2006:23).

27

2.2. Methodology

2.2.1 Goal & Scope of the Study

The aim of this study is to provide a calculation (or rather, more accurate estimation)

of the carbon footprint of a loaf of bread produced by the Breadshares Community

Bakery.

The purpose of this study is to evaluate the environmental impact of producing a loaf

of bread in the Bakery, to inform the consumers of these impacts and by comparing

this data with that of an “ordinary” loaf of supermarket bought bread, allowing the

consumer to see the environmental performance offered by organic farming and a

shortened supply chain.

The scope of this study is a business to consumer (B2C) (as defined by PAS 2050), as

the customer is the end point for the bread (BSI 2008b:3) and is similar in scope to a

cradle-to-grave analysis. The study will be PAS 2050 compliant based, where

required, on primary data specific to the Breadshares Community Bakery.

The use of the PAS 2050 methodology was chosen for a number of reasons. Firstly

the only major and accessible study of the carbon footprint of bread in the United

Kingdom (Espinoza-Orias et al 2011) also used the PAS 2050 methodology. This

allows for direct comparisons to be made between different bread.

Secondly PAS 2050 diverges from ISO 14044 in a number of ways which made it

more appropriate for this study given the time constraints.

As per Section 5.5 land use change is only included in the life cycle assessment if the

change took place after the 1st January 1990 (BSI 2008a:9; 2008b:28). This is in line

with the IPCC guidelines that assume that all emissions resulting from land use

change have completed after twenty years.

Emissions resulting from the production of capital goods, such as tools & machinery

are excluded from a life cycle assessment under PAS 2050 methodology (BSI

28

2008a:13; 2008b:32), as there is normally a lack of data for most capital goods, and

such analyses add extra cost and complexity to the LCA (BSI 2008b:32).

Another nuance of PAS 2050 is the inclusion threshold for components of the

functional unit to be included in the LCA. Section 6 states that a source contributing

to less than 1% of the total emissions may be excluded from the LCA, yet the total

proportion of those excluded may not exceed 5% of the total footprint (BSI 2008a:12-

16; 2008b:14). Also excluded are human energy inputs to processes, the transport of

consumers to and from the point of retail purchase and the transport of employees to

and from their normal place of work (BSI 2008a:16).

Unlike ISO 14044, PAS 2050 specifically requires that primary data is used where

possible (BSI 2008a:17) although the requirement does not apply to downstream

emissions (BSI 2008a:17) i.e. those components that are imported into the Bakery

from external suppliers, which in this study would be yeast, water and salt. The

requirement also does not apply when implementing the requirement would involve

physically measuring the GHG emissions (BSI 2008a:17), allowing for the use of

models in calculating the emissions from agricultural processes.

All data collected is converted into emissions data by multiplying the activity by the

specific emission factor for that activity, and is then expressed as per the functional

unit. All emissions then need to be converted into CO2e (carbon dioxide equivalent)

by multiplying by the relevant global warming potential (GWP) figure, as set out in

Table 1.1.

All emissions data is then added together, as per the proportions for the functional

unit in order to give the carbon footprint of the functional unit.

The functional unit for this study as defined by PAS 2050 is an unsliced loaf of bread

weighing 900g (2lbs), made from organic wholewheat flour, produced on a medium

scale and sold for consumption at home. The scope of the study is from ‘cradle-to-

grave’ although the data for the consumption will be based on a previous study

(Espinoza-Orias et al 2011), as explained in Section 2.2.2.4.

29

The functional unit, loaf of bread, is composed of the ingredients and at the

proportions as described in Table 2.1.

Ingredient Weight Proportion of loaf (%) Wholewheat flour 600g 59.23

Salt 5g 0.49 Yeast 8g 0.79 Water 400g 39.49

Table 2.1: Ingredients of a Breadshares Bakery loaf

As defined by PAS 2050 (BSI 2008b) the functional unit and scope of the study are

suitable for carbon labelling the product and communicating with the consumer.

2.2.2 System Boundaries

The following stages & processes are included within the system boundary, using the

stages set out by PAS 2050 (BSI 2008b:11):

1. Raw Materials

a. Farming: Cultivation, harvesting, drying and storage of grain

b. Other ingredients from external suppliers: water, salt & yeast

2. Processing

a. Wheat milled into flour

b. Ingredients mixed, proved, baked and cooled

3. Retail/Distribution

a. Storage of bread at ambient temperature in farm shop – daily

b. Possibility of distribution via van to customers in Edinburgh

4. Consumption

a. Bread stored at room temperature, refrigerated or frozen

b. Bread consumed either as is, or toasted

5. Waste Management

a. Disposal of bread & any packaging

30

2.2.2.1 Raw Materials

Farming includes all the processes required for the cultivation of the organic wheat,

harvesting, drying and storage. The wheat is to be grown (following a two year trial)

onsite at Whitmuir Farm, using a 6 year rotation cycle of 1 year pig grazing, 3 years

grass/clover cover and 2 years of wheat. In the two year trial, it was found that pigs

and clover provided enough nutrients to enable a successful crop yield for one year

(with a protein content of 13%), although a second was not evaluated. Field

operations including ploughing, seed distribution and harvesting are carried out using

machinery. At Whitmuir Farm, the land has been used for agriculture since before

1990 and thus the GHG emissions arising from land use change do not need to be

considered.

The other ingredients used to make the bread are yeast, salt and water. Water is

currently taken from the domestic water supply provided by Scottish Water, although

there is scope to eventually extract water from a burn on the farm. The yeast and salt

are purchased from downstream manufacturers.

Initially, the bread will be sold direct to consumers onsite via the Whitmuir Farmshop,

meaning that no packaging is required for the produce. However there are preliminary

plans for the eventual implementation of a distribution system. This would be similar

to vegetable box schemes, with a van delivering loaves to customer’s homes in

Edinburgh and the Lothians a number of times a week. This would require packaging

in order to keep the bread covered during transportation, most likely in the form of

paper bags, although it is not inconceivable that a re-usable fabric bag could also be

used.

2.2.2.2 Processing

The first stage of processing is milling the harvested and dried wheat into flour. This

process uses a fairly small electric grain mill that turns a pair of millstones to produce

between 75kg to 100kg of flour an hour.

31

The extraction rate of the wheat, defines the type of flour produced (Espinoza-Orias et

al 2011:354). A 75% rate produces white flour, 85% rate produces brown flour and

100% (meaning all of the grain is included in the flour) produces wholewheat flour

(Espinoza-Orias et al 2011:354). It is this last type that will be used for the

Breadshares flour.

The second stage of processing is the preparation of the dough by mixing the

ingredients and then kneading. This is all carried out by hand, with the dough being

left to prove (rise) naturally for a couple of hours.

The final stage is baking. This is carried out in an electric powered oven, although a

wood fired oven was also initially considered. The oven initially uses energy to heat

up to the required temperature; once at that, no more power is required as it is

sufficiently well insulated to allow it to retain heat for a prolonged period. Over time,

some heat does dissipate; although the temperature of the oven never drops down by a

great amount, meaning that less energy is required to reheat the oven to baking

temperatures.

Whitmuir Farm has just installed a 50kw wind turbine, and it is hoped that this will

provide sufficient power to the mill, oven and shop (at different times), although due

to the unpredictability of nature, it is expected that there will be periods when power

demand will exceed the generation capacity.

To this end it was decided to calculate three carbon footprints based on different

electricity mixes, which should provide enough data to efficiently cover all

eventualities.

Scenario A. 100% on-site renewable

Scenario B. 50/50 on-site renewable/grid

Scenario C. 100% grid

2.2.2.3 Retail

The finished loaves will be sold in the existing Whitmuir Farm shop; stored at an

ambient temperature and sold on the same day as baking. As this utilises existing

32

premises and has no additional energy demands, it is assumed that this stage does not

contribute anything to the product’s carbon footprint.

There are proposals to implement a delivery scheme across Edinburgh and the

Lothians for the Breadshares Bakery bread, although this is not included in the system

boundary.

2.2.2.4 Consumption

As no first hand data is available for the methods of consumption of the Breadshares

Bakery bread, the consumption pattern data is based on that of Espinoza-Orias et al

(2011).

Product Category Rules (PCR) set by the Carbon Trust were used in the study by

Espinoza-Orias et al (2011:354), and are also used here. They state that in the home,

61% of bread is eaten as is, with 39% being toasted; 72% of bread is stored at ambient

temperature with 20% frozen for over 10 days, and 8% chilled for 4 days.

However for this study it is assumed that all bread is stored at ambient temperature

with 39% of the loaf being toasted.

2.2.2.5 Waste Management

Again the amount of bread wasted by the consumer is unknown. Studies suggest that

up to 30% of food in the UK is wasted (WRAP 2008; Williams & Wikström 2011)

although this does include inedible parts of food such as bone. Due to the

demographic of purchasers of organic produce, it is thought that the consumers of

Breadshares Bakery bread would waste something closer to the region of less than

10% of the bread. Further more it is expected that any wastage incurred by the

consumer would not end up in landfill but would instead be used as bird feed and the

like.

33

2.3 Data Sources

As previously discussed PAS 2050 requires that primary data be used “for all

processes and materials owned, operated or controlled by the footprinting

organistaion” (BSI 2008b:17). In this project the requirement for primary data covers:

• Cultivation of wheat

• Milling

• Baking

Secondary data will be used for:

• GWP data

• Production of yeast

• Production of salt

• Production/distribution of water

• Electricity generated off-site

• Consumption

o Chilled and frozen storage

o Toasting

As also mentioned in clause 7.3, primary data is not required if it would necessitate

physically measuring GHG emissions (BSI 2008a:17), therefore emissions generated

during the cultivation of the wheat can be calculated using a carbon footprinting

model for agriculture.

For this stage a number of different models were evaluated. One developed by the

Scottish Agricultural College (not publicly available) and currently in beta mode, and

one, AgriLCA9, developed by the Silsoe Research Institute at Nuffield University as

part of the Defra Project IS0205 (Williams et al 2006; Williams et al 2010) into the

environmental burdens of agriculture.

AgriLCA was chosen as it was designed specifically for modelling emissions from

crops, rather than the whole farm scenario modelling carried out by the SAC model. It

9 https://webapps2.cranfield.ac.uk/webforms/form.jsp?formId=12024

34

was therefore able to be specifically tweaked to fit the agricultural methods used to

grow the wheat at Whitmuir Farm.

Primary data on milling and baking was supplied by members of the Breadshares

Bakery.

All secondary data satisfies the PAS 2050 criteria (BSI 2008b:19) that it should be

sourced from peer-reviewed publications, government publications and official UN

publications where possible.

35

2.4 Results

The results here are set out in the order as defined in section 2.1.

2.4.1 Life Cycle Inventory

The Figures below set out the energy flows for the life cycle of a Breadshares loaf of

bread; Figure 2.1 shows the overall flows, whereas Figures 2.2 & 2.3 show the energy

flows for specific components of the life cycle.

36

Figure 2.1 Energy flows for ‘cradle-to-grave’ analysis of Breadshares loaf

37

Figure 2.2 Detailed energy flows for the Raw Materials stage

Figure 2.3 Detailed energy flows for Processing stage

38

2.4.2 Life Cycle Inventory Analysis

2.4.2.1 Raw Materials

The AgriLCA was utilised to model the emissions generated during the cultivation,

harvesting and drying/storage stage of the wheat. The results are presented in Table

2.2.

Impacts & resources used

Organic Primary Energy used, GJ 1.38 Global Warming Pot'l, t (100 year) CO2 Equiv. 0.40 Distribution of GWP by gas CO2 26% CH4 0% N2O (direct) 57% N2O (secondary and other gases, e.g. CO) 17%

Table 2.2 Emission results for the organic wheat

The cultivation, harvest and storage of one tonne of organic wheat generates 0.40

tCO2e in emissions; which equates to 0.4kgCO2e emissions for 1kg of wheat.

The wheat is then milled into flour. The mill used can produce between 75kg and

120kg of flour an hour, and has a power rating of 6.25kWh. Using the conservative

yield value of 100kg, 1kg of milled flour has a power consumption of 0.0625kWh. In

Scotland the average emission factor for 1kWh of electricity is 0.362 kgCO2e (The

Scottish Government 2011)

For the different electricity supply scenarios listed above, the emissions for milling 1

kg of flour are as follows:

Scenario A. 0 kgCO2e

Scenario B. 0.01131 kgCO2e

Scenario C. 0.02262 kgCO2e

39

Therefore 1kg of wholewheat flour has a carbon footprint of:

Scenario A. 0.4 kgCO2e

Scenario B. 0.41131 kgCO2e

Scenario C. 0.42262 kgCO2e

No emissions data is available for the yeast used in the baking process, in fact it is

very difficult to find a figure for the carbon footprint of yeast anywhere, and is

something being addressed by a major study launched in 2010 (COFALEC 2010).

Instead a value was obtained from the Simapro 6.0 database; this provided a carbon

figure of -0.0556kgCO2e per kilogram of yeast.

The value is negative as Simapro calculates the sugar beets used in yeast production

absorb more CO2 from the atmosphere than is emitted during their cultivation

(Bimpeh et al 2006:12).

The emissions data for the salt was also obtained from the Simapro 6.0 database; this

gave a value of 0.167kgCO2e per kilogram of salt used.

Scottish Water (2010) have calculated that the carbon footprint of supplying one litre

of water to be 1.5x10-4 kgCO2e (Scottish Water 2010:6).

Ingredient Weight (kg)

Emissions per kg (kgC02e)

Emissions (kgCO2e)

Wholewheat flour Scenario A 0.6 0.4 0.24 Wholewheat flour Scenario B 0.6 0.41131 0.246786 Wholewheat flour Scenario C 0.6 0.42262 0.253572

Yeast 0.08 -0.0556 -0.004448 Salt 0.05 0.167 0.00835

Water 0.4 1.5x10-4 6.0×10-5 Total Scenario A 0.243962 Total Scenario B 0.250748 Total Scenario C 0.257534

Table 2.3 Carbon footprint of each raw material

40

2.4.2.2 Processing

Conservative values for the power consumption per loaf for the baking stage give a

value of 0.180kWh per loaf. Using the emission factor of 0.362 kgCO2e (The Scottish

Government 2011) per kW of electricity give the following emissions for each

scenario:

Scenario A. 0 kgCO2e per loaf

Scenario B. 0.03258 kgCO2e per loaf

Scenario C. 0.06516 kg CO2e per loaf

2.4.2.3 Consumption

Espinoza-Orias (2011:357) calculated that the power consumption for toasting a slice

(40g) of wholewheat bread is 0.047kWh, which gives emissions of 0.01701 kgCO2e

per 40g slice of bread (assuming that all electricity used in the consumption phase is

the Scottish average).

Since the assumption is that 39% of the loaf is toasted, this equates to 351g of bread

or 8.775 slices, giving a total of 0.1493 kgCO2e emissions for the consumption stage.

2.4.2.4 Loaf Carbon Footprint Total

Stage Scenario A Scenario B Scenario C Raw Materials

0.243962 0.250748 0.257534

Processing 0 0.03258 0.06516 Consumption 0.1493 0.1493 0.1493

Total= 0.393262 kgCO2e per loaf

0.432628 kgCO2e per loaf

0.471994 kgCO2e per loaf

Table 2.4 Carbon footprint of a loaf under each scenario

41

0.00

0.05

0.10

0.15

0.20

0.25

0.30

0.35

0.40

0.45

0.50

Scenario A Scenario B Scenario C

kgC

0 2e Consumption

ProcessingRaw Materials

Figure 2.4 Breakdown of the 3 carbon footprints

2.4.3 Results Analysis

The carbon footprint of a loaf of bread baked by the Breadshares Bakery ranges from

0.39kgCO2e to 0.47kgCO2e depending on the mix of electricity used; for each

scenario, the raw materials accounted for the largest share of the footprint, although in

Scenario C, the processing & consumption stages combined almost matched the raw

materials for emissions.

In all scenarios the raw materials obtained from downstream sources contribute less

than 4% to the carbon footprint, and this contribution may be even less if primary data

was available for the salt and yeast.

In all three scenarios, the cultivation of the wheat accounts for the greatest CO2e

emissions; although the use of grid electricity in the consumption stage accounts for

30% or greater of emissions in all Scenarios.

42

Scenario A

60%

0%

1%

2%

0%

0%

37%Wheat CultivationWheat MillingYeastSaltWaterBakingConsumption

Figure 2.5 Breakdown of carbon footprint for Scenario A loaf

Under Scenario A, where all the electricity used in the production of the loaf is

generated from the on farm wind turbine, the consumption stage accounts for over a

third of the carbon footprint. This is also a stage that the producers have no control

over which cannot be lowered aside from encouraging consumers to switch to

renewable energy suppliers.

43

Scenario B

54%

2%1%

2%

0%

7%

34%

Wheat CultivationWheat MillingYeastSaltWaterBakingConsumption

Figure 2.6 Breakdown of carbon footprint for Scenario B loaf

In Scenario B, where a 50/50 mix of onsite generation and ‘standard’ electricity was

used, the wheat cultivation still emits the majority of emissions per stage. However

when the electricity use (milling, baking and consumption) is added together, it

accounts for 43% of emissions.

44

Scenario C

49%

3%1%

2%

0%

14%

31%

Wheat CultivationWheat MillingYeastSaltWaterBakingConsumption

Figure 2.7 Breakdown of carbon footprint for Scenario C loaf

The use of 100% grid electricity sees a change is the breakdown of the carbon

footprint. Wheat cultivation still remains the single largest emitter by process; but

overall electricity consumption now accounts for 48% of the emissions from a loaf of

bread. The contribution of milling to emissions increases to 3% of the total with

baking contributing to 14% of the total emissions.

45

2.5 Discussion

In all three scenarios (Table 2.5), the Breadshares loaf has a lower carbon footprint

than any other UK loaf (where data has been published), and is similar to studies on

the continent (Andersson & Ohlsson 1999; Braschkat et al; Williams & Wikstrom

2011). Although it should be noted that bread on the continent is of a different style

and form to UK bread and is thus not a suitable comparison for the Breadshares bread.

Product

Carbon Footprint (kgCO2e) Scenario

A Scenario

B Scenario

C Espinoza-

Orias (2011)

PAS 2050

Espinoza-Orias (2011)

Generic

Allied Bakery (2009)

White - - - 1.20 1.07 1.3 Wholewheat 0.39 0.43 0.47 1.16 1.00 1.3

Brown - - - 1.03 1.2 Table 2.5 Comparison of the carbon footprints of different breads in different studies

Bread baked under Scenario A, which is the primary method used by the Breadshares

Bakery, has a carbon footprint less than half that of any other study, and is less than a

third of the Allied Bakery wholewheat loaf.

Bread baked under Scenario C, using 100% grid electricity has a carbon footprint that

is still less than half of any other study, and just over a third of the Allied Bakery

wholewheat loaf.

Life Cycle Stage

% Contribution Scenario

A Scenario

B Scenario

C Espinoza-

Orias (2011) PAS 2050

Espinoza-Orias (2011)

Generic

Allied Bakery (2009)

Raw Materials 63 59 55 41 45 45 Wheat Cultivation 60 54 49 35 32

Wheat Milling 2 3 3 5 Ingredients 3 3 3 19 12

Processing 7 14 16 7 21 Packaging 1 4 2 Transport 4 5 4 Retail 4 2 2 Consumption 37 34 31 25 26 23 Waste Management 6 6 3

Table 2.6 Relative contribution of the life cycle stages to the carbon footprint of the breads

46

As can be seen from Table 2.6 most of the Breadshares bread lifecycle stage

contributions are broadly similar to those identified in other studies. Scenario A is the

anomaly since it has no emissions from electricity use, meaning that the wheat

cultivation is a much larger proportion of the overall emissions.

Packaging, transport, retail and waste management account for roughly 15% of the

carbon footprint of the other bread types, equating to, on average, 170gCO2e of

emissions. If such a value were to be incorporated into the carbon footprints

calculated in this study, then the Breadshares bread would still outperform any of the

other UK breads, although Scenario C bread would be within with 0.25kgCO2e of the

wholewheat, thick sliced bread calculated under the generic study (Espinoza-Orias

2011:360).

The emissions generated during the wheat cultivation (0.4tCO2e per tonne) are half of

those calculated for organic wheat (0.8tCO2e per tonne) by Williams et al (2010:864).

The savings here can be attributed to 0.62GJ less energy use in the cultivation of the

Breadshares wheat, as well as the lack of mineral fertiliser used in the cultivation and

the exclusion of capital goods from the study.

The life cycle analysis has shown that in all three studies, a hot spot for emissions is

the consumption stage (toasting), which creates 0.149kgCO2e emissions. The carbon

footprint could be lowered by between 31% and 37% if consumers were encouraged

not to toast their bread, or to switch to a greener electricity source, although this is not

an area that the producers can have a direct influence over.

The hotspots identified in this study, wheat cultivation and consumption, are the same

as those identified by Espinoza-Orias et al (2011).

The oven used during the processing stage contributes to reducing the emissions per

loaf of bread. If a standard method of baking were to be used, whereby the oven is

heated up to the required temperature and is then maintained at that temperature until

it is switched off at the end of the baking day, the power consumption per loaf of

bread would be around 0.601kWh, over three times that required by a Breadshares

47

loaf. In terms of emissions, using the three scenarios the baking stage (using a generic

oven) would account for:

Scenario A: 0 kgCO2e per loaf

Scenario B: 0.1088 kgCO2e per loaf

Scenario C: 0.2176 kgCO2e per loaf

Thus by using a well insulated oven, carbon savings of up to 0.15 kgCO2e per loaf,

around one third of the total emissions for a loaf, are made.

If the proposed delivery scheme to the Edinburgh & Lothians region was

implemented, then around 0.218kgCO2e would be added to a delivered loaf of bread.

This is composed of an estimated 0.206kgCO2e for a 44 mile round trip for the

delivery van, and 0.012kgCO2 (Berners-Lee 2010:21) for a recycled paper bag.

Whilst adding on up to two thirds to the carbon footprint, a loaf of Breadshares Bread

would still outperform any of the other loaves.

Opportunities for reducing the use of farm diesel, which accounts for the majority of

the primary energy use in the wheat cultivation, and thus reducing the cultivation

stage emissions, are limited.

This study demonstrates the environmental benefits of a localised food production

system using organic wheat, and an on-site generated renewable electricity source

where possible. Both Scenarios B & C show that using grid electricity can add up to

230gCO2e emissions to the product, yet even so they still outperform any other bread.

48

Chapter 3: Food, Farming and Sustainability

3.1 Introduction

As has been seen, the growing of wheat organically i.e. without the use of

agrochemicals and following the standards set by the Soil Association, in addition to

cutting down on the distance the product has to travel has a dramatic effect on

reducing the carbon footprint of a loaf of bread. What implications then, does this

have on ideas of sustainability, farming and food?

Firstly we will look at energy use in agriculture. As peak oil becomes a greater issue,

will this force a change in the way that agriculture is carried out?

Secondly organic farming will be compared to conventional farming. We have

already seen that organic practices can reduce GHG emissions associated with

agriculture, but is there scope for this to be done in conventional farming as well?

What other benefits does organic farming provide over conventional farming? Are

there any disadvantages?

Thirdly the concept of local food and food miles will be examined. As ideas of green

living have entered every day life, many people have turned to local food, which

which travels much less distance, as more sustainable than produce that is imported

from around the world. Is this actually a correct view of the global food system? Are

food miles the best indicator of this?

As discussed in Section 1.3 the way that food is processed, prepared and

manufactured can include many additives and ingredients that take away from the

nutritional value of the food. For further information on the concept of food and well-

being and to examine links between increases in allergies and other dietary problems

& highly processed food there is a wealth of literature. Of particular interest are

publications by The Soil Association (2003), Whitley (2009), Jiang et al (2010) and

Block et al (2011).

49

3.2 Energy Use in Agriculture and Peak Oil

The world wide demand for oil reached a peak in 2010 with 87.4 million barrels a day

being consumed (BP 2011:9). This is a 1.9million barrel increase on the previous

global peak of 85.6m in 2007 (BP 2011:9), which had been followed by two years of

declining consumption due to rising prices (BP 2010:16). It should, however, be noted

that oil consumption in the UK has been in a steady decline since 2005 (1.8m barrels

per day to 1.6m barrels per day) (BP 2011:9).

Whilst the vast majority of the UKs consumption is accounted for by transportation, a

significant amount is also used in agriculture (1.86% of total UK energy use) (White

2007:105). Of this 30% is direct energy use, with the remaining 70% resulting from

indirect energy use (White 2007:105).

Direct energy use is the consumption of fuel in the operation of agricultural

machinery and equipment, as well as electricity and gas use for heating greenhouses,

drying crops and lighting and heating other buildings (Arizpe et al 2011:23). Indirect

energy use relates to the energy consumed in the production of technological inputs

such as capital goods (machinery & equipment) as well as agro-chemicals such as

pesticides and fertilisers (Arizpe et al 2011:23-4).

The carbon savings identified in this study are mainly made in the indirect energy use

category, as organic farming eschews the use of fertilisers & pesticides, thus reducing,

to an extent, the reliance of agriculture on oil, which is something that could become

key in the future.

Agro-chemicals (pesticides and fertilisers) are currently synthesised from fossil fuels

(Heinberg 2005:197). Nitrogen fertiliser in the form of ammonia is created through

the Haber-Bosch process which uses an estimated 10GW (Madrigal 2008) of gas,

accounting for around 1% of global energy consumption, to break the triple bond

structure of atmospheric nitrogen and form ammonia. It takes one tonne of oil and 108

tonnes of water to produce one tonne of nitrogen fertiliser, whilst emitting 7 tonnes of

carbon dioxide equivalent GHGs in the process (Soil Association 2008:7-8). Fertiliser

50

created through the Haber-Bosch process is thought to have helped grow 40% of the

worlds food supply.

In 2002, the USA used 0.6 exajoules worth of fertiliser and pesticides (Schnepf

2004:5) which was equivalent to the entire energy use of Mexico. Whilst this is not

comparable to the UK, what is clear is the high dependency that agriculture has on oil

in order to provide the yields, and thus the food security that the developed world has

come to enjoy (Arizpe et al 2011).

Figure 3.1 Primary energy use in agriculture 1971-1995 (From Woods et al 2010:2992).

Light blue line, total fertilizers per ha cropland; brown line, cereal yield;

purple line, total area equipped for irrigation; green line, tractors per ha;

dark blue line, agricultural labour per ha cropland.

The concept of peak oil was first introduced by Paul Hubbert in 1956 (Heinberg

2005:97). He observed that oil production follows a bell curve; initially production is

low during the discovery phase, but as time passes more wells are dug, increasing

production (Heinberg 2005:97). After a certain point; ‘the peak’, the reserves are

harder to access and production declines. This normally occurs when half of the oil

reserve has been drained and the oil becomes increasingly hard to reach. Due to

impracticalities an oil reserve is never completely emptied, as extracting the last

amounts is both prohibitively high in cost and more often than not impossible

(Heinberg 2005:98).

51

Figure 3.2 Hubbert’s bell curves for global peak oil (From Heinberg 2005:99)

Hubbert predicted that the peak in US production would occur between 1966 and

1972, it occurred in 1970.He also predicted that the global peak would occur between

1990 and 2000 (Figure 3.2) (Heinberg 2005:97-8) however this latter prediction was

not realised as advances in technology allowed for oil fields to be more accurately

updated (Heinberg 2005:98). There is no clear consensus on when the peak will

occur, with recent predictions (Table 3.1) covering a time span of only 30 years

(Leggett 2007:9).

Year Author 2005 Kenneth Deffeyes 2006 Henry Groppe 2007 Ali Samsam Bakhtiari 2007 Richard Duncan 2007 ODAC 2010 Colin Campbell 2013 Rembrandt Koppelaar 2015 Jean Laherrere 2015 PFC Energy 2020 CERA 2030 USGS

Table 3.1 Studies suggesting peak oil dates (Leggett 2007:9)

Matt Simons (2006) has suggested that the global peak will occur when Saudi Arabia

reaches its peak, as it is the possessor of the world’s spare production capacity.

52

Some have argued that even when we reach what we believe to be peak oil, this will

not present a challenge as there are a few trillion barrels of oil waiting to be

discovered in reserves not yet found (Leggett 2007: 9). This claim however is

disputed by a small, but growing, number of analysts who reckon that the amount left

is below 1 trillion and these are in reserves that will be very difficult to locate and

extract from (Leggett 2007:9).

What is clear is that whilst we do not know quite when the peak will occur, if it has

not already passed, we are expecting it to happen relatively soon, and this has many

implications for the future.

In order to try and reduce our dependence on crude oil, one solution that has been

developed by various governments worldwide is that of biofuels. These are crops such

as switchgrass and corn that are grown specifically to be turned into biofuels (Roberts

2004:79) such as ethanol (Heinberg 2005:174) which can then be used to power

engines as a replacement to petrol and diesel.

Whilst biofuels are an attractive alternative when oil prices are high, they are a

significant drain on arable land (Monbiot 2004; Heinberg 2005:175). Calculations

show that in the UK one hectare of arable land can provide 1.45 tonnes of transport

biofuel a year (Monbiot 2004). Given that the UK transport sector consumes

37.6million tonnes of fuel a year, 25.9 million hectares would be required to supply

the fuel demand (Monbiot 2004). The UK currently has 5.7 million ha of arable land,

so in order to fulfil a 100% biofuel target, 5 times this would be required to satisfy the

demand. To even reach the European Union target of a minimum of 10% of fuel from

biofuels by 2020 (EU 2007) would require around half of the UK’s current arable

land, and this has worrying implications for food supply and food security.

In 2007 a quarter of the USA’s corn harvest was diverted to biofuel production

(Kingsbury 2007) and this is a pattern that can be seen in many countries globally.

This reduces the availability of food around the world in order to satisfy a largely

impractical green policy. What this does is to reduce a country’s ability to feed itself,

making them more reliant on food imports, and thus more susceptible to rises in food

53

prices. In 2008 food prices rose dramatically (Figure 3.3), due to poor harvests, an

increase in biofuel production and a lack of exports. Wheat increased in price by

130% (BBC 2008) and this had the knock-on effect of causing food riots around the

world (The Times 2008).It also had the consequence that countries, who are normally

exporters of grain, to halt exports in order to supply their domestic market, further

increasing the price of food.

Figure 3.3 Energy and food prices 1992-2008 (From BBC 2008)

As a side note, the environmental impacts of biofuel should be mentioned.

Commentators still disagree over the energy balance of biofuel (Heinberg 2005), a

recent study published in Science (Fargione et al 2008; Searchinger et al 2008) found

that many studies in favour of biofuels that highlight their value as a climate change

mitigation tool, failed to take into account the impact of land use change (as forestry

is cleared to increase the land available to grow biofuel crops). When this factor was

included in evaluations, corn ethanol and soy biodiesel have twice the emissions of

petroleum products (Fargione et al 2008; Grunwald 2008).

It is plain to see that the increase in yield experiences from the middle of the 20th

century onwards is mostly due to the high energy inputs that fossil fuels provide

(Arizpe et al 2011). The global food supply is now dependent on oil in order to

continue feeding the growing global population.

Once we reach peak oil and supplies start to decline, it is likely that prices will rise,

and that restrictions will be placed on the use of oil. Then, as Heinberg says “it is not

difficult to imagine the likely agricultural consequences” (2005:196).

54

Initially food prices would rise (Woods et al 2010:2998; Arizpe et al 2011:21) which

would most likely be followed by food shortages that could be Malthusian in their

nature (indeed it was advances in technology during the Green Revolution that largely

prevented Malthus’ theory happening). This could bring about a massive decrease in

population (Heinberg 2005; Soil Association 2007; Arizpe et al 2011), although this

is worst case scenario.

In order to weather a future of declining oil supplies, it is clear that agriculture needs

to de-energise as much as possible. Whilst some savings can be made in direct energy

use; machinery can be made more fuel efficient and used a little less and renewable

energy sources can be used to power infrastructure such as dryers, greenhouses and

building, we cannot scrap the use of machinery altogether, whilst maintaining an

adequate food supply.

In 1900 40% of the UK’s population was employed in agriculture, this figure has now

declined to less than 1% in the present day (Heinberg 2007:14). The number who

once would have been employed in agriculture are now employed in other sectors of

the economy; with 50% of the UK population living in urban areas, it would require a

major shift in the structure of the UK demographics and economy to increase the

number of workers in agriculture to an extent where machinery use could be

dramatically reduced, and this is a largely impossible task (Heinberg 2007).

Where significant savings can be made is in indirect energy consumption. This would

require a shift away from chemical fertilisers and pesticides to pre-1950s farming

methods when “farming was almost exclusively a solar industry” (Pimentel &

Giampietro 1994). Studies of energy use within agriculture suggest that the adoption

of organic farming practices provide a significant energy reduction (Amate & de

Molina 1011; Gomiero et al 2011). A report for the Danish Government (Hansen et al

2001) found that a 100% adoption of organic methods would reduce agricultural

energy use by 9-51% depending on certain parameters. It has been argued that yields

provided by organic farming are lower than those from conventional farming

(Gomiero et al 2011) whilst other studies have found yields to be comparable (Clark

et al 1999; Pimentel et al 2005). If yields did decrease, an expansion of agricultural

55

lands would be possible in most countries, although this would have implications of

increased GHG emissions from land use change.

Alternatively a shift in diet could provide the answer. At the moment around half of

all grain is diverted for animal feed (Goodland 1997:195) where is it inefficiently

used to produce meat for “the minority higher-income sectors of society” (FAO 1995;

Goodland 1997:195). A shift in diet away from meat, towards a more grain based one

would allow greater amounts of grain to be used for human consumption, reducing

concerns relating to organic farming yields and increasing food security.

Finally, peak oil will have an impact on travel and transportation; limited oil would

restrict the ability to transport food produce by road and air, although it is likely that

there would be limited trade utilising rail and canals (Hopkins 2007:19). This could

force a shift back towards localised agriculture and food systems, which are explored

further in Section 3.4.

56

3.3 Conventional and Organic Farming: a Comparison

Here the term ‘conventional farming’ refers to the farming method that uses agro-

chemicals such as fertilisers and pesticides, and in developed countries has become

increasingly intensive, extensive and monoculture. The vast majority of farming in the

UK is conventional.

Organic farming on the other hand eschews the use of chemicals; it is “a holistic

production management system that avoids the use of synthetic fertilisers, pesticides

and genetically modified organisms, minimises pollution of air, soil and water, and

optimises the health and productivity of interdependent communities of plants,

animals and people” (Scialabba & Müller-Ludenlauf 2010:159). In the EU organic

produce labelled organic must satisfy certain criteria in order to obtain its certification

(Scialabba & Müller-Ludenlauf 2010; Gomiero et al 2011:99), with produce only

being allowed to be sold as organic if at least 95% of the ingredients are organic.

Those who farm organically often do so to preserve the natural environment, amid

concerns that conventional farming can have a negative impact upon the flora, fauna

and ecosystem services of an area as well as on resources such as soil fertility and

water quality; these issues are discussed later in this section.

Of particular concern with regards to conventional farming is the large scale use of

agro-chemicals, as well as the creation of mega-fields through the removal of

hedgerows and other boundary features. This in addition to the fact that most farms

concentrate on single crop species in an area can have a negative impact on the

biodiversity of a region.

It is estimated that in the UK 300kg of N are applied per hectare per year (Conway &

Pretty 1991:159), in conventional farming. Theoretically around 90% of applied

fertiliser can be recovered by the plants and soil; however the actual figure is

normally between 20 and 70% (Conway & Pretty 1991:212) with the lost fertiliser

becoming a pollutant.

Fertiliser lost through run off can end up in water bodies such as rivers, lakes and

streams. Here it causes eutrophication and results in a number of issues within the

57

water (Skinner et al 1996:119). At first growth amongst aquatic species of flora is

promoted, especially of algal species which are highly responsive to nitrogen and

phosphorus. This results in a dense bloom that causes the death of other aquatic

species in a number of ways (Skinner et al 1996:119). The bloom starves other

species of light and then eventually the algae sinks to the bottom of the water body.

As it decays it creates anoxic conditions, which can lead to a rapid decline in resident

species.

There are a number of environmental and economic implications related to the

eutrophication of terrestrial waters as identified by the FAO (FAO 1996):

• Shift in habitat characteristics due to change in aquatic plants

• Loss of desirable species of fish e.g. salmon

• Production of toxins by certain algae

• Loss of recreational use of water due to slime, weed infestation and noxious odour

Fertiliser can also affect domestic water supplies; algal blooms can block water

treatment plants and leave undesirable odours and tastes in drinking water (Conway &

Pretty 1991:198, Skinner et al 1996:120). Nitrates can also leach through the soil into

groundwater supplies, although the full extent is not known as transition time through

the underlying geology can be up to 40 years (Conway & Pretty 1991:183). Thus

fertiliser can cause a considerable increase in the costs of treating water supplies

(Skinner et al 1996:119, Pretty et al 2000:117).

As can be expected the impacts of pesticides on the environment are much higher than

those of fertilisers. The inherent flaw of pesticides is that they are indiscriminate by

nature; they may be designed to attack certain pests by targeting specific

characteristics but will also attack anything else with the same characteristics

(Conway & Pretty 1991:24). It has been calculated that only about 5% of the applied

pesticide reaches the intended organism (Miller 2009:149), with the remainder

entering the environment as a pollutant. Such losses can have significant impacts

upon the environment, particularly on local flora and fauna, which will briefly be

outlined below.

58

In the wider environment pesticides can move into the atmosphere and can be

redeposited though rainfall far away from the site of their application. Contamination

of surface water through runoff is relatively rare in the United Kingdom, although it

can occur after periods of heavy rain (PAN 2010:11). Pollution from point sources is

more common (Skinner et al 1996:113), and instances of this are dealt with under UK

legislation. Leaching through soils into groundwater supplies does also occur,

requiring extensive and expensive treatment for domestic supplies, it has been

estimated that such treatment costs annually around £140m in the UK alone (Pretty et

al 2000:117).It is widely documented that the use of pesticides has had significant

impacts upon the biodiversity of areas where they are applied (Moore 1967). Not only

do pesticides remove the weeds which are the first link in the food chain for many

species (PAN 2010:3) but they can also be ingested through the eating of treated

plants, causing poisoning within animals.

Between 1990 and 2006 the area of British farmland treated with pesticides rose by

38% (Fera 2009) but diversity of plant species found within fields declined (PAN

2010:12). This has been attributed to both the use of pesticides but also other changes

in agriculture such as the removal of hedgerows.

Soil fertility is also affected by pesticides; studies have shown that pesticides can

remove nitrates from the soil and they can also reduce the number of earthworms

within the soil (PAN 2010:13). This is a catch 22 situation for farmers who have to

apply more fertiliser to compensate for the decrease in soil fertility.

Faunal species can also be directly poisoned by the spraying of pesticides over crops.

Some 10m breeding individuals of ten species of farmland bird have disappeared

between 1979 and 1999 (Krebs et al 1999:411), with farmland bird populations

falling by 51% between 1970 and 2007 (DEFRA 2009:57). The deaths of other

animals have also been attributed both directly and indirectly to the spraying of

pesticides (Skinner et al 1996:115, Conway & Pretty 1991, Chadwick 1993, Boatmen

et al 2004, PAN 2010).

One of the most notable species whose decline in recent years has been attributed to

pesticides is that of the honey bee (PAN 2010:9). In the UK between 1995 and 2001,

59

85% of reported bee poisonings were caused by pesticides (PAN 2010:9), with further

estimates that modern farming practices are responsible for the loss of ca. 2000

colonies a year (Pretty et al 2000:127). Research has also demonstrated that pesticides

have altered the behaviour of honey bees (Decourtye et al 2003).

Since organic farming does not make use of chemical fertilisers and pesticides, none

of the issues presented above occur on organic farms.

Without chemical pest (insect and weed) control, these can become an issue on

organic farms (Gomiero et al 2011:97). Zhu et al (2000) have argued that with

increasing intensification and monoculture, crops vulnerability to pests and disease

increases. Therefore by increasing biodiversity & habitats (common in organic

agriculture), natural pest control can compensate for the lack of chemical pesticides

(Gomiero et al 2011:108). It has been shown that organically managed soils enhance

the nutrient balance in plants, which can increase resilience to pest attack (Phelan et al

1996; Alyokhin et al 2005; Gomiero et al 2011). The increasing abundance of birds

on organic farms can also provide weed and pest containment (Westerman et al

2003); studies in the Netherlands (Mols & Visser 2002) found that the introduction of

the Parus major L to apple orchards reduced the number of pest caterpillars by up to

99%, increasing yields from 4.7kg to 7.8kg per tree.

It would be reasonable to suggest that a reduction in the use of pesticides that is

accompanied by a rise in biodiversity would also experience a rise in the number of

pests; this is not always the case. Pesticides can disrupt the natural predators of pests,

allowing pest numbers to increase unchecked (if they develop resistance to the

chemicals). When pesticide use is stopped, this allows for natural pest control to re-

develop and a number of studies have shown no increase in organic yield losses to

pests (Gomiero et al 2011:109), although it should be noted that introducing non-

native species as pest control is not recommended as they can become invasive

species themselves (Thomas & Reid 2007).

Weeds can remain an issue; studies in Scotland (Hawesa et al 2010) found

significantly greater numbers of weeds on organic farms and this is a trend found

worldwide (Hole et al 2005:115). Whilst birds (see above) can be used for weed

60

control, many organic farmers result to either manual weed clearing (significantly

increasing the number or workers required) or flame weeding (significantly increasing

the fuel consumption of the farm), with the latter generating substantial amounts of

GHG’s.

The majority of studies into biodiversity (number of species & species numbers) and

agriculture have found that it is greatly enhanced on organic farms when compared

with conventional farms (Hole et al 2005; Gomiero et al 2011:106). Of 65 studies

analysed by Bengtsson et al (2005), 53 (84%) found enhanced biodiversity, although

a number of authors have suggested that carefully managed conventional agriculture

could achieve similar results (Gibson et al 2007).

In terms of numbers, organic farms have been found to have 74-153% more weed

species compared to conventional farms, as well as, 68-105% more spiders, 16-62%

more birds and 6-75% more bats (Gomiero et al 2011:107). Bat activity is between

61-84% higher on organic farms (Hole et al 2005:117) and birds are in greater

abundance. A study in Sweden (Rundlof et al 2008) found a greater abundance of

butterflies on organic farms, although an earlier study (Weibull et al 2003) found no

difference in biodiversity between organic and conventional farms. Here the authors

suggest that rather than the farming style, the heterogeneity of the landscape has a

bigger influence on biodiversity (Gomiero et al 2011:107).

Table 3.2: The effects of organic farming on biodiversity, compared to

conventional farming (From Hole et al 2005:122)

Diverse landscapes have a greater number of habitats and are thus able to support a

greater range of biodiversity; conventional farming often lowers heterogeneity

through the removal of hedgerows and promotion of monoculture. By eschewing

61

agro-chemicals and promoting a greater number of crop varieties, with longer crop

rotations, as well as encouraging hedgerows and set-a-side, organic farming creates a

greater on farm heterogeneity and thus encourages biodiversity.

For this to work to its full effect, landscape level heterogeneity must also be

increased, since the positive environmental effects of one organic farm can easily be

outweighed by the impacts of conventional farming in the surrounding landscape.

Benton et al (2003) have argued that rather than concentrating on farming style, focus

should be shifted to promoting diversity across the landscape in order to increase

biodiversity; since organic farms remain a minority, their full benefits may not be

fully realised due to the negative effects from conventional farming.

Aside biodiversity, organic farming can also have a positive effect on soils. Intensive

farming can lead to soil erosion and losses of soil organic matter (SOM) (Gomiero et

al 2011:100). On conventional farms, such issues are usually fixed through the

addition of extra chemicals to the soil, but this is not available in organic farming.

What has been observed however is that under organic conditions, SOM improves

naturally over time.

In America, a 40 year long study (Reganold et al 1987) found that compared to

conventional soils, organics had on average a 3cm thicker surface horizon and 16cm

deeper topsoil, as well as experiencing soil loss of less than 75% of the maximum

region tolerance, whereas conventional losses were three times that. A study by

Pimentel et al (2005) found that soil carbon increases on organic farms were almost

30% compared to only 8.6% on conventional farms. A 150 year study in Britain found

a 120% increase in SOM and soil N levels compared to only a 20% increase on

conventional farms using fertiliser (Gomiero et al 2011:101).

Organic soils also have increased pools of stored nutrients, with stability of

percolation and aggregate between 10-60% higher than conventional soils (Gomiero

et al 2011:101). Planting cover crops increases soil stability and prevents soil erosion,

providing that the vegetation cover is kept year round (Gomiero et al 2011:1010). Soil

health can be indicated by high amounts of earthworms, arthropods and microbial

biomass; with organic soils being found to have up to 320% greater abundance of

62

earthworms and microbial biomass when compared to conventional soils (Hole et al

2005:116; Gomiero et al 2011:105).

Compared with conventional soils, organic soils appear to have a greater water

retention capacity (Swiss trials found water holding capacity to be 20-40% greater)

which provides organic crops with the ability to fare well during droughts (Gomiero

et al 2011); organic yields during drought periods have been demonstrated to be

between 70-90% higher than conventional yields during drought periods.

A 1% increase in SOM can add 10-11 litres of plant available water per hectare to

soils (Sullivan 2002), and this is potentially very important at a time where pumped

irrigation could be limited and where climate is becoming increasingly variable,

although extensive experimentation to “gain better understanding of the complex

interactions of farming practices, environmental characteristics and agroecosystem

resilience” (Gomiero et al 2011:103) has been called for.

It has already been discussed how organic farming has a lesser energy burden, and

thus lower overall GHG emissions than conventional farming. It can also provide

opportunities to reduce greenhouse gas emissions associated with agriculture and can

mitigate against atmospheric CO2 through carbon sequestration (Adler et al 2007;

Johnson et al 2007; Smith et al 2008; Eglin et al 2010; Scialabba & Müller-Ludenlauf

2010).

Figure 3.4 Sources of N2O and CH4 emissions in the USA (From Johnson et al 2007:109)

63

In agriculture, methane emissions (Figure 3.4) are a result of livestock production,

waste decomposition (including crop residues) and rice paddies (Johnson et al 2007;

Smith et al 2008). Methane emissions from agriculture could be reduced by up to

56% through careful management practices (Smith et al 2008:802) and it has been

suggested that CH4 uptake by soils could offset up to 21% of cattle emitted CH4

(Johnson et al 2007:115); both of these can be carried out in either farming type, thus

organic farming does not offer any opportunities to reduce CH4 emissions compared

with conventional farming (Stolze et al 2000:59).

By avoiding the use of chemical fertiliser, organic farming straight away avoids direct

N2O emissions, which account for 10% of global agricultural emissions (Scialabba &

Müller-Ludenlauf 2010:161). Organic manures (used in place of chemical fertilisers)

can result in greater N2O emissions (Figure 3.4) compared with chemical N fertilisers,

although this is highly dependent on soil types and not always the case (Scialabba &

Müller-Ludenlauf 2010:161). The use of cover crops in organic farming increase N2

fixation and thus absorb greater amounts of N, reducing N2O emissions from topsoil

(Scialabba & Müller-Ludenlauf 2010:161; Gomiero et al 2011:102), as well as

keeping greater amounts of N within the plant system.

A number of trials have found that organic soils perform better in preventing N

leaching than conventional soils (Gomiero et al 2011:102). Compacted soils are a

major source of N2O emissions and since organic soils have enhanced aeration, this

risk is mitigated (Scialabba & Müller-Ludenlauf 2010:161). Overall organic systems

have around 66% less N2O emissions than conventional farming (Stalenga & Kavalec

2008).

CO2 emissions from organic agriculture arise from the combustion of fossil fuels

during the operation of farm machinery. Here emissions can only be reduced through

less use of machinery (or through the use of biofuels (see Section 3.2)); practices such

as conservation tillage can lead to less machinery use (Johnson et al 2007:111; Smith

et al 2008:791; Gomiero et al 2011:104) potentially reducing global CO2 emissions

by 15% (Lal 2004) but again it is not an approach unique to organic farming. And has

64

been seen, some practices can lead to increased fossil fuel consumption (Stolze et al

2000:68) compared to conventional farming.

Many organic practices such as mulching, continuous cropping, cover cropping,

legume rotations and manure applications can improve the carbon content of organic

soils (Johnson et al 2007:112; Eglin et al 2010:712) and thus organic farming can be a

method to improve the balance of agricultural greenhouse gas emissions (Leifield &

Fuhrer 2010:586). Pretty et al (2002) found that organic soils have carbon

accumulation increase from 0.3 to 3.5t per hectare per year, although some have

warned that such a sink can only be temporary, lasting around 100 years (Foeried &

Høgh-Jensen 2004).

Soils can also be used to manually sequester carbon, through the addition of black C

such as biochar (Woods et al 2010:3003). Calculations by Lee et al (2010) indicate

that in 1 hectare of arable land, 303.8 tons of carbon can be stored. The United

Kingdom possesses some 6.2m ha of arable land, providing the storage potential for

1.8GtCyr-1 of biochar. This could potentially offset over 300% of UK emissions;

although it is highly unlikely that the full potential would ever be realised, manual

sequestration of carbon into organic soils does offer a significant GHG mitigation

opportunity.

As well as the carbon sequestration, the addition of biochar to arable soils has a

number of other advantages; field trials have shown that biochar increases soil

hydraulic conductivity, permeability and holding capacity (Stavi & Lal 2010:165). It

also reduces soil acidity (Pratt & Moran 2010:1150), reduces nutrient leaching,

decreases N20 emissions (by 50%), suppresses CH4 emissions and increases fertiliser

efficiency and crop yields (Gaunt & Lehmann 2010:4152, 4155; Stavi & Lal

2010:165; Pratt & Moran 2010:1150; Atkinson et al 2010).

65

3.4 Local Food Production, Food Miles and Sustainability Implications

The transportation of food currently accounts for 18% of total energy use in the UK

food sector (White 2007:1243), equating to 2% of the UK total energy consumption.

The majority of transportation is carried out by HGV; with food transportation

accounting for 25% of all HGV vehicle kilometres in the UK (24.6bn km), causing

the emission of 10m tonnes of CO2 (AEA 2005:ii). The annual amount of food

moved by HGV has increased by 23% since 1978 (AEA 2005:i).

As previously mentioned, the depletion of oil supplies could lead to the greater

adoption of alternative forms of transport such as canals, rail and sea to move produce

around the UK.

The concept of food miles has become increasingly popular in the UK (Saunders &

Barber 2008; Coley et al 2009; Chi et al 2009) as both producers and consumers have

sought to examine the environmental credibility of products, especially their carbon

emissions. Food miles have become “powerful polemical tools in policy discourses

built around sustainable agriculture and alternative food systems” (Coley et al

2009:150) but are they really a proper indicator of sustainability?

A number of studies (AEA 2005; Saunders & Barber 2008; Coley et al 2009) have

established that the idea of freighted food having a great environmental impact than

local food can often be incorrect. In their study for Defra, AEA (2005) demonstrated

that tomatoes can be grown in Spain and freighted to the UK with less emissions than

if they were grown directly in the UK. This is due to UK tomatoes needing to be

grown in heated greenhouses outside of summer months and thus requiring greater

energy inputs (AEA 2005:v) which gave UK tomatoes greater emissions. Saunders &

Barber (2008) found that the majority of New Zealand food imports to the United

Kingdom had lower carbon emissions than UK grown equivalents.

They found that for most New Zealand products, the chemical inputs to agriculture

were at least half that of UK products (meaning less overall emissions), as well as the

fact that it was less emitting to freight New Zealand apples to the UK at any time of

66

the year compared to keeping UK apples in refrigerated storage until they were

needed (Saunders & Barber 2008:81).

It is also the case that vegetables grown by farmers in Africa often have lower

emissions associated with them than UK vegetables. This is because they are farmed

manually with little mechanisation or chemical inputs (McKie 2008) although once

airplane emissions are factored in, this figure can be up to 12 times greater than UK

vegetables (Chi et al 2009:38). What this fails to take into account however is the fact

that up to 80% of fruit and vegetables flown out of Africa are mostly transported via

backloading i.e. they are carried in the cargo hold of UK bound passenger planes

which would have flown anyway (Chi et al 2009:38) and thus the transport stage of

these products is insignificant in terms of emissions.

Of course, if the local produce is organic, then many of the above arguments are

negated, as the emissions from the organic farming will most likely be less than those

of freighted produce.

Food miles also fail to take into account other aspects of the global food market.

Through the export market, the importing of produce in the UK, provides economic

development opportunities for farmers in developing countries (MacGregor & Vorley

2006). In 2005 exports to the UK from sub-Saharan Africa had a declared value of

£200 million (MacGregor & Vorley 2006:3) and provided employment for around 1.5

million people (both directly in agriculture and indirectly in related business such as

transport, packaging and so forth) (MacGregor & Vorley 2006:7). This allows

individual farmers to move away from subsistence farming by providing access to the

global export market and through this individuals in developing countries can

experience improved incomes and higher standards of living.

It is therefore reasonable to suggest that the food miles are not an accurate indicator of

the sustainability (or green credentials) of a product. Focussing should instead be on

producing a carbon footprint for the product via a full life cycle analysis, as this will

be able to show its full environmental impact and enable consumers to make ‘green’

choices when purchasing produce.

67

The other side of the argument to the above mentioned international development

aspects of a global food market, the local food market is shown to have numerous

benefits for communities in the UK (Milestad et al 2010). The definition of local food

is not defined by any official characteristic, instead the consumer sets their own

definition of what they view as local (Milestad et al 2010:229), although by its nature

local food is normally fresher, more ‘authentic’ and in many cases unprocessed

(Milestad et al 2010:228). Local food allows the consumer to have much more

information about the ecological costs of the produce they purchase, due to a

shortened supply chain whereby the producer often sells direct to the consumer

(Sundkvist et al 2001:218) and by purchasing either direct from the producer, or via

local shops and farmers markets more of the money spent remains in the local

economy (Martinez et al 2010:42).

A study by the New Economics Foundation into the economy of local produce, found

that for every £10 spent on a local organic box scheme £25 is generated for the local

economy, compared to only £14 if the equivalent was spent in a supermarket (Pretty

2001:6). They also suggested that if every business and person in the area switched

1% of their current spending to local goods and services then an extra £52 million

could be generated in the local economy. Money put into local produce stays in the

local economy as the farmer uses some of the money to purchase a drink at the local

pub, the landlord spends some of that money on servicing his car at the local garage

and so on; if this money is spent at a supermarket, the money leaves the area almost

instantly.

In turn a greater demand for local produce and an increase in money available in the

local economy can bring about the creation of jobs either directly (working in the

farm) or indirectly in supporting roles (such as butchers, bakers, shopkeepers, delivery

drivers etc.).

As with the Breadshares Community Bakery, investment in local business allows

producers to purchase supplies up front and allows them to embark on projects that

traditional sources of funding (i.e. the bank) might have deemed too risky.

68

The local food system is also a source of community cohesion. Local shops and

delivery schemes allow individuals to meet and talk on a regular basis; it can ensure

that the elderly and infirm are regularly checked on and helped out (Lawrence

2004:123) and it can provide localised advertising for jobs and services carried out by

individuals within the area (Pretty 2001:5).

There are also ecological conservation aspects of local food; individuals purchasing

local organic produce may be doing so on the basis that the farming practices are

ecologically sound/environmentally friendly and thus by purchasing this produce,

they are investing in the protection of local ecology.

Studies of local bread networks in Austria (Milestad et al 2010) and Sweden

(Sundkvist et al 2001) found that locals participated in the networks, purchasing

products from them even though cheaper ‘non-local’ alternatives were available

(Sundkvist et al 2001:225) indicating that local produce had a greater value attached

to it.

When interviewing participants (producers and consumers) in the networks, it was

found that overall the participants in both networks had the same reasons for doing so

(Milestad et al 2010):

• Artisan production methods

• Organic farming

• High quality products

• Social interactions

• Benefiting the local economy

The authors of the Austrian study summed up the network as “social closeness

connected to the mode of production via shared values” (Milestad et al 2010:237) and

this is a phrase that could be used to describe those involved in the Breadshares

Community Bakery.

As we have seen, the concept of food miles itself is not a valid indicator of a product’s

sustainability. Food that is imported can be more environmentally friendly than

69

produce grown locally and the export market has provided economic growth for

farmers in developing countries. However if local food is produced organically it can

have a very low environmental impact and purchasing local food can have numerous

benefits for a community.

70

Chapter 4: Conclusion

The examination of organic farming, localised production and sustainability has

brought about a number of conclusions.

The adoption of organic farming offers considerable benefits; adoption of organic

farming can save up to 51% of energy use associated with agriculture and would

make food supply less dependent on oil thus increasing food security at a time when

oil production is at its peak.

The environmental benefits that organic farming can provide are numerous, the most

important aspects being that chemical pesticides and fertilisers are avoided,

preventing water and air pollution and not harming biodiversity. The preservation and

re-introduction of hedgerows and set-a-side provide habitats and increase the

heterogeneity of the landscape, encouraging biodiversity.

Organic farming can also go someway to reducing GHG emissions from agriculture

and mitigating CO2 emissions already present in the atmosphere, through the

improvement of soil carbon and by manually sequestrating carbon into the soil

through materials such as biochar. The latter, however, is not unique to organic

farming and is a mitigation strategy that could also be carried out in conventional

farming.

A number of the environmental benefits offered by organic farming could also be

achieved through carefully managed conventional farming. Whether this be through

the careful application of agro-chemicals or the re-establishment of habitat areas such

as hedgerows to encourage biodiversity, conventional farming is not as damaging to

the environment as may be portrayed.

Although yields may be lower under some circumstances in organic farming, this

does not necessarily have to impact upon food security since lower yields can still

adequately feed the global population if there is a switch to a less meat based diet.

71

The concept of food miles has been demonstrated to be a poor indicator of a product’s

environmental credentials. Instead the full life cycle of a product must be evaluated to

fully understand the impact that it has. Whilst importing produce from abroad can

offer carbon savings in certain conditions, and can provide economic relief to

producers in developing countries, local food also has a number of benefits to the

local area. It can lead to job creation and an improvement of the local economy; for

every £10 spent on local produce, there is a net benefit of £25 to the local economy.

The carbon footprint calculated for a loaf of bread created by the Breadshares Bakery

ranges from 0.39kgCO2e to 0.47kgCO2e depending on the mix of electricity used

during the production stage. These figures were between half and two thirds less than

the carbon footprints of breads calculated in other studies, with the major reductions

in emissions due to the organic farming method, the absence of transport between

production nodes and the use of on-site generated electricity.

If a delivery scheme for Breadshares bread was to be implemented, it would add on

up to an extra 66% to the carbon footprint of a loaf, although this would still perform

better than other loaves of bread. As well as being more environmentally friendly in

the long run, as delivering to seventy addresses over 40 miles is better than those 70

people individually driving to purchase bread.

This demonstrates the sustainability of projects such as the Breadshares Bakery which

shorted the chain of production and reveals how the carbon footprint of foods could

be reduced in order to try and mitigate against climate change.

72

Appendix A: Detailed Calculations for Life Cycle Inventory Analysis

Input Amount Source Raw Materials

Flour –Wheat Cultivation

kg CO2e per kg wheat 0.4 AgiLCA model

Flour – Wheat Milling

Mill yield per hour (kg) 100 Farmer interview

Power consumption of mill

(kWh)

6.25 Farmer interview

Power consumption per kg

flour (kWh)

0.0625 Calculation: power

consumption of mill / mill

yield

kg CO2e per kWh 0.362 The Scottish Government

kg CO2e per kg milled wheat Scenario A: 0

Scenario B: 0.01131

Scenario C: 0.02262

Calculation: power

consumption per kg x

emissions per kWh

kg CO2e per kg flour Scenario A: 0.4

Scenario B: 0.41131

Scenario C: 0.42262

Calculation: kg CO2e per kg

wheat + kg CO2e per kg

milled wheat

Flour

kg wheat per loaf 0.6 Baker interview

kg CO2e per loaf Scenario A: 0.24

Scenario B: 0.24678

Scenario C: 0.25357

Calculation: emissions per kg

flour x kg wheat per loaf

Yeast

kg CO2e per kg -0.0556 Emissions database

kg yeast per loaf 0.08 Baker interview

kg CO2e per loaf -0.004448 Calculation: emissions per kg

yeast x kg yeast per loaf

Salt

kg CO2e per kg 0.167 Emissions database

kg salt per loaf 0.05 Baker interview

kg CO2e per loaf 0.00835 Calculation: emissions per kg

salt x kg salt per loaf

73

Water

kg CO2e per kg 1.5x10-4 Scottish Water

kg water per loaf 0.4 Baker interview

kg CO2e per loaf 6.0×10-5 Calculation: emissions per kg

water x kg water per loaf

kg CO2e per loaf Scenario A: 0.243962 Scenario B: 0.250748 Scenario C: 0.257534

Calculation: emissions from

flour per loaf + emissions

from yeast per loaf +

emissions from salt per loaf +

emissions for water per loaf

Processing

Generic Oven

Power consumption of oven

(kWh)

24.72 Baker Interview

Capacity of oven (loaves) 36 Baker Interview

Oven operation time (hours) 1 hour (15 minutes heating

up + 45 minutes per baking

period)

Baker Interview

Baking Periods 2 (72 loaves = 1 hour 45

mins)

Baker Interview

Power consumption per loaf

(kWh)

0.601 Calculation: (power

consumption of oven x

operation time)/capacity

kg CO2e per kWh 0.362 The Scottish Government

kg CO2e per loaf Scenario A: 0 Scenario B: 0.1088 Scenario C: 0.2176

Calculation: power

consumption per loaf x

emissions per kWh

Breadshares Oven

Power consumption of oven

(kWh)

5.162 Baker Interview

Capacity of oven (loaves) 25 Baker Interview

Oven operation time (hours) 8 Baker Interview Baking Periods Up to 9 (For this 15 minutes

initial heating + 2 baking

periods of 45 minutes used)

Baker Interview

Power consumption per loaf 0.180 Calculation: (power

74

(kWh) consumption of oven x

operation time)/capacity

kg CO2e per kWh 0.362 The Scottish Government

kg CO2e per loaf Scenario A: 0 Scenario B: 0.03258 Scenario C: 0.06516

Calculation: power

consumption per loaf x

emissions per kWh

Consumption

Power consumption per slice

(40g) of bread (kWh)

0.047kWh Espinoza-Orias et al (2011)

kg CO2e per kWh 0.362 The Scottish Government

Slices of bread toasted per

loaf

8.775 Calculation: (39% of loaf) /

40g

kg CO2e per loaf 0.1493 Calculation: power

consumption per slice x

emissions per kWh x no.

slices

Total per loaf (kg CO2e) Scenario A: 0.393262 Scenario B: 0.508848 Scenario C: 0.624434

Calculation: emissions raw

materials + emissions

processing + emissions

consumption

Proposed Delivery

Round trip distance (miles) 44 Calculation

kg CO2e per litre of diesel 2.672 DEFRA (2010)

Van fuel economy (mpg) 37 Van average

Van fuel economy (mpL) 8.13 Calculation: mpg / 4.55

Number of loaves per van 70 Baker Interview

kg CO2e per loaf 0.206 Calculation: ((distance / fuel

economy) x

emissions)/number of loaves

Proposed Packaging

kg CO2e per bag 0.012 Berners-Lee (2010)

Proposals total per loaf (kg CO2e)

0.218 Calculation: transport

emissions per loaf +

packaging emissions per loaf

75

Bibliography

Adler, P.R., Del Grosso, S.J. & Parton, W.J. (2007) ‘Life-Cycle Asssessment of Net

Greenhouse-Gas Flux for Bioenergy Cropping Systems’ Ecological Applications

17, pp. 675-691

AEA (2005) The Validity of Food Miles as an Indicator of Sustainable Development.

Final Report produced for Defra. Available from

http://archive.defra.gov.uk/evidence/economics/foodfarm/reports/documents/food

mile.pdf [Last Accessed 29th July 2011]

Alexander, W. (2010) 52 Loaves, Algonquin Books of Chapel Hill, Chapel Hill

Alyokhin, A., Porter, G., Groden, E., and Drummond, F. (2005) ‘Colorado potato

beetle response to soil amendments: A case in support of the mineral balance

hypothesis?’ Agriculture, Ecosystems & Environment 109, pp. 234–244

Amate, J.I. & de Molina, M.G. (2011) ‘‘Sustainable de-growth’ in agriculture and

food: an agro-ecological perspective on Spain’s agri-food system (year 2000)’,

Journal of Cleaner Production xx pp.1-9

Andersson, K. & Ohlsson, T. (1999) ‘Life Cycle Assessment of Bread Produced on

Different Scales’ International Journal of Life Cycle Assessment, 4, pp. 25-40

Andersson, K. (2000) ‘LCA of Food Products and Production Systems’ International

Journal of Life Cycle Assessment, 5, pp. 239-248

Arizpe, N., Giampietro, M. & Ramos-Martin, J. (2011) ‘Food Security and fossil

energy dependence: an international comparison of the use of fossil energy in

agriculture (1991-2003)’ Critical Reviews in Plant Science, 30, pp. 45-64

Ashton, J. (1904) The History of Bread from Prehistoric to Modern Times, Brooke

House Publishing, London

76

Ashton, T.S. (1977) The Industrial Revolution 1760-1830, Oxford University Press,

Oxford

Atkinson, C.J., Fitzgerald, J.D. and Hipps, N.A. (2010) ‘Potential mechanisms for

achieving agricultural benefits from biochar application to temperate soils: a

review’ Plant Soil, 337, pp. 1-18

BBC (2008) The cost of food: facts and figures. Available from:

http://news.bbc.co.uk/1/hi/in_depth/7284196.stm [Last Accessed 28th July 2011]

Bengtsson, J., Ahnstrom, J., and Weibull, A-C. (2005) ‘The effects of organic

agriculture on biodiversity and abundance: A meta-analysis’ Journal of Applied

Ecology 42, pp. 261–269

Benton, T. G., Vickery, J. A., and Wilson, J. D. (2003) ‘Farmland biodiversity: Is

habitat heterogeneity the key?’ Trends Ecological Evolution 18, pp. 182–188

Berners-Lee, M. (2010) How Bad are Bananas? The Carbon Footprint of Everything,

Profile Books, London

Bimpeh, M., Djokoto, E., Doe, H. & Jequier, R. (2006) LCA of the Production of

Home made and Industrial Bread in Sweden.Available from

http://www.infra.kth.se/fms/utbildning/lca/projects%202006/Group%2003%20(Br

ead).pdf [Last Accessed 20th July 2011]

Block, L.G., Grier, S.A., Childers, T.L., Davis, B. et al (2011) ‘From Nutrients to

Nurturance: A Conceptual Introduction to Food Well-Being’ Journal of Public

Policy and Marketing 30, pp. 5-13

Boatman, N.D., Brickle, N.W., Hart, J.D. et al (2004) 'Evidence for the indirect

effects of pesticides on farmland birds', IBIS 146, pp. 131-143

77

BP (2010) Statistical Review of World Energy 2010. Available from

http://www.bp.com/sectionbodycopy.do?categoryId=7500&contentId=7068481

[Last Accessed 27th July 2011]

BP (2011) Statistical Review of World Energy 2011 Available from

http://www.bp.com/sectionbodycopy.do?categoryId=7500&contentId=7068481

[Last Accessed 27th July 2011]

Braschkat, J., Patyk, A., Quirin, M. & Reinhardt, G.A. (2010) Life cycle assessment of

bread production – a comparison of eight different scenarios. Available from:

http://www.lcafood.dk/lca_conf/contrib/g_reinhardt.pdf [Last Accessed 29th July

2011]

BSI (2008a) Specification for the assessment of the life cycle greenhouse gas

emissions of good and services, British Standards Institution, London

BSI (2008b) Guide to PAS 2050. How to assess the carbon footprint of goods and

services, British Standards Institution, London

Chadwick, D. (1993) Crop Protection and Sustainable Agriculture, Symposium on

World Food Production by Means of Sustainable Agriculture

Chi, K.R., MacGregor, J. & King, R. (2009) Fair Miles: Recharting the food miles

map, iied. Available from: http://pubs.iied.org/15516IIED.html [Last Accessed

30th July 2011]

Clapp, B.W. (1994) An Environmental History of Britain since the Industrial

Revolution, Longman, London

Clark, M.S., Horwarth, W.R., Shennan, C. et al (1999) ‘Nitrogen, weeds and water

and yield-limiting factors in conventional, low-input and organic tomato systems’

Agriculture, Ecosystems & Environment 73, pp. 257-270

78

Clarkson, L.S. (1972) The Pre-Industrial Economy in England 1500-1750, Batsford,

London

COFELAC (2010) Establishing the yeast carbon-footprint. Available from

http://www.cofalec.com/Default.aspx?lid=1&rid=76&rvid=146 [Last Accessed:

2nd August 2011]

Coley, D., Howard, M. & Winter, M. (2009) ‘Local food, food miles and carbon

emissions: A comparison of farm shop and mass distribution approaches’ Food

Policy, 34, pp. 150-155

Conway, Gordon R. & Pretty, J.N. (1991) Unwelcome harvest : agriculture and

pollution Earthscan Publications, London

Cook, M. & Dunbar, L. (2008) Rituals, Roundhouses and Romans. Excavations at

Kintore, Aberdeenshire 2000-2006 Vol 1, STAR Publications, Edinburgh

Daunton, M.J. (1995) Progress and Poverty An Economic and Social History of

Britain 1700-1850, Oxford University Press, Oxford

Decourtye, A., Lacassie, E. & Pham-Delegue, M. (2003) 'Learning performances of

honeybees (Apis mellifera L) are differentially affected by imidacloprid according

to the season', Pest Management Science 59, pp. 269-278

DEFRA (2009) Sustainable development indicators in your pocket 2009, DEFRA,

London

DEFRA (2010) GHG Conversion Factors for Company Reporting. Available from:

http://www.defra.gov.uk/environment/economy/business-efficiency/reporting/

[Last Accessed 8th August 2011]

Dixon, N. (2004) The Crannogs of Scotland. An underwater archaeology, Tempus

Publishing, Stroud

79

Ecoinvent (2007) Ecoinvent Database v 2.0

Elgin, T., Ciais, P., Piao, S.L. et al (2010) ‘Historical and future perspectives of

global soil carbon response to climate and land-use changes’ Tellus B 62, pp. 700-

718

Ehrlich, P.R. & Holdren, J.P (1971) ‘Impact of population growth’, Science 171, pp.

1212-1217

Espinoza-Orias, N., Stichnothe, H. & Azapagic, A. (2011) ‘The carbon footprint of

bread’, International Journal of Life Cycle Assessment, 16, pp. 351-365

EU (2007) EU makes bold climate and renewables commitment. Available from:

http://www.euractiv.com/en/energy/eu-bold-climate-renewables-

commitment/article-162373 [Last Accessed 1st August 2011]

FAO (1996) Control of Water Pollution from Agriculture, Irrigation & Drainage

Paper 55, FAO, Rome

Fargione, J., Hill, J., Tilman, D. et al (2008) ‘Land Clearing and the Biofuel Carbon

Debt’, Science 319, pp. 1235-1238

Foereid, B., and Høgh-Jensen, H. (2004) ‘Carbon sequestration potential of organic

agriculture in northern Europe – a modelling approach’ Nutrient Cycling in

Agroecosystems. 68, pp. 13–24

Gélinas, P., Morin, C., Reid, J.F. & Lachance, P. (2009) ‘Wheat cultivars grown

under organic agriculture and the bread making performance of stone-ground

whole wheat flour’, International Journal of Food Science and Technology, 44,

pp. 525-530

Gibson, R. H., Pearce, S., Morris, R. J., Symondson,W. O. C., and Menmott, J. (2007)

‘Plant diversity and land use under organic and conventional agriculture: A

whole-farm approach’. Journal of Applied Ecology 44, pp. 792–803

80

Gomiero, T., Pimentel, D. & Paoletti, M.G. (2011) ‘Environmental Impacts of

Different Agricultural Management Practices: Conventional vs Organic

Agriculture’ Critical Reviews in Plant Science, 30, pp. 195-124

Goodland, R. (1997) ‘Environmental sustainability in agriculture: diet matters’

Ecological Economics 23, pp. 189-200

Gronroos, J,. Seppalla, J., Voutilainen, P., Seuri, P. & Koikkalainen, K. (2006)

‘Energy use in conventional and organic milk and rye bread production in

Finland’, Agriculture, Ecosystems and Environment, 117, pp. 109-118

Grübler, A. (1998) Technology and global change, Cambridge University Press,

Cambridge

Grunwald, M. (2008) ‘The Clean Energy Scam’ Time Magazine. Available from:

http://www.time.com/time/magazine/article/0,9171,1725975-1,00.html [Lat

Accessed 28th July 2011]

Guant, J.L. and Lehmann, J. (2008) ‘Energy Balance and Emissions Associated with

Biochar Sequestration and Pyrolysis Bioenergy Production’, Environmental

Science and Technology, 42, pp. 4152-4158

Hansen, B., Alroe, H.F. & Kristensen, E.S. (2001) ‘Approaches to assess the

environmental impact of organic farming with particular regard to Denmark’

Agriculture, Ecosystems & Environment 83, pp. 11-26

Hansen, B., Alroe, H.J & Kristensen, E.S. (2001) ‘Approaches to asses the

environmental impact of organic farming with particular regard to Denmark’

Agriculture, Ecosystems and Environment 83, pp. 11-26

Hansson, P.A. & Mattsson, B. (1999) ‘Influence of Derived Operation-Specific

Tractor Emission Data on Results from an LCI on Wheat Production’

International Journal of Life Cycle Assessment, 4, pp. 202-206

81

Hawesa, C., Squirea, G. R., Hallett, P. D.,Watsonb, C. A., and Young, M. (2010)

‘Arable plant communities as indicators of farming practice’. Agriculture,

Ecosystems & Environment 138, pp. 17–26

Heinberg, R. (2005) The Party’s Over. Oil, War and the Fate of Industrial Societies,

Clairview, Forest Row

Heinberg, R. (2007) ‘The essential re-localisation of food production.’ In Soil

Association (eds) One Planet Agriculture. Preparing for post-peak oil food and

farming future. The case for action, Soil Association, Bristol

Hole, D.G., Perkins, A.J., Wilson, J.D. et al (2005) ‘Does organic farming benefit

biodiversity?’, Biological Conservation 122, pp. 113-130

Hopkins, R. (2007) ‘A vision of food and farming in 2030. The case for an energy

descent plan for UK agriculture’. In Soil Association (eds) One Planet

Agriculture. Preparing for post-peak oil food and farming future. The case for

action, Soil Association, Bristol

IPCC (2001) Climate Change 2001: The Scientific Basis, Cambridge University

Press, Cambridge

IPCC (2007) ‘Summary for Policymakers’. In: Climate Change 2007: The Physical

Science Basis. Contribution of Working Group I to the Fourth Assessment Report

of the Intergovernmental Panel on Climate Change . Cambridge University Press,

Cambridge

ISO (2006) Environmental management – Life cycle assessment – Requirements and

guidlines (ISO 14044:2006), CEN, Brussels

Jiang, B., Ni, L. & Buckle, K. (2010) ‘Food for Health and Wellbeing: 14th Congress

of Food Science and Technology’, Journal of the Science of Food and Agriculture

90, Special Edition

82

Johnson, J.M-F., Franzluebbers, A.J., Weyers, S.L. & Reicosky, D.C. (2007)

‘Agricultural opportunities to mitigate greenhouse gas emissions’, Envionmental

Pollution, 150, pp. 107-124

King, S. & Timmins, G. (2001) Making sense of the Industrial Revolution, English

economy and Society 1700-1850, Manchester University Press, Manchester

Kingsbury, K. (2007) ‘After the Oil Crisis, a Food Crisis?’, Time Magazine. Available

from

http://www.time.com/time/business/article/0,8599,1684910,00.html?iid=sphere-

inline-sidebar [Last Accessed 28th July 2011]

Krebs, J.R., Wilson, J.D., Bradbury, R.B. & Siriwardena, G.M. (1999) ‘The Second

Silent Spring?’ Nature 400, pp. 611-612

Kussmaul, A. (1990) A General View of the Rural Economy of England 1538-1840,

Cambridge Univeristy Press, Cambridge

Lal, R. (2004). Soil carbon sequestration impact on global climate and food security.

Science 304, pp. 1623–1627

Lawrence, F. (2004) Not On The Label, what really goes into the food on your plate,

Penguin Books, London

Lee, J.W., Hawkins, B., Day, D.M. and Reicosky, D.C. (2010) ‘Sustainability: the

capacity of smokeless biomass pyrolysis for energy production, global carbon

capture and sequestration’, Energy and Environmental Science, 3, pp. 1695-1705.

Leggett, P. (2007) ‘The Peak Oil Problem’. In Soil Association (eds) One Planet

Agriculture. Preparing for post-peak oil food and farming future. The case for

action, Soil Association, Bristol

Leifield, J. & Fuhrer, J. (2010) ‘Organic Farming and Soil Carbon Sequestration:

What Do We Really Know About the Benefits?’ AMBIO 29, pp. 585-599

83

Macgregor, J. & Vorley, B. (2006) Fair Miles? Weighing environmental and social

impacts of fresh produce exports from sub-Saharan Africa to the UK, Fresh

Insights Number 9. Available from:

http://www.agrifoodstandards.net/en/filemanager/active?fid=74 [Last Accessed

30th July 2011]

Madrigal, A. (2008) ‘How to Make Fertilizer Appear Out of Thin Air, Part 1’, Wired.

Available from http://www.wired.com/wiredscience/2008/05/how-to-make-nit/

[Last Accessed 27th July 2011]

Malthus, T. (1798) An Essay on the Principle of Population, re-printed in 1970 by

Penguin Books, London

Marchant, J., Reuben, B. & Alcock, J. (2008) Bread: A Slice of History, The History

Press, Stroud

Martinez, S., Hand, M., Da Pra, M., Pollack, S. et al (2010) Local Food Systems.

Concepts, Impacts and Issues, ERR97. Available from:

http://permanent.access.gpo.gov/lps125302/ERR97.pdf [Last Accessed 30th July

2011]

McKie, R. (2008) ‘How the myth of food miles hurts the planet’ The Observer.

Available from:

http://www.guardian.co.uk/environment/2008/mar/23/food.ethicalliving [Last

Accessed 30th July 2011]

Meisterling, K., Samaras, C. & Schweizer, V. (2009) ‘Decisions to reduce greenhouse

gases from agriculture and product transport: LCA case study of organic and

conventional wheat’ Journal of Cleaner Production, 17, pp. 222-230

Middleton, N. (1999) The Global Casino. An introduction to environmental issues,

Arnold Publishers, London

84

Milestad, R., Bartel-Kratochvil, R., Leitner, H. & Axmann, P. (2010) ‘Being close:

The Quality of social relationships in a local organic cereal and bread network in

Lower Austria’ Journal of Rural Studies, 26, pp. 228-240

Millennium Ecosystem Assessment (2005) Volume 1: Current States and Trends,

Island Press, Washington D.C.

Miller, G.T. (2009) Sustaining the Earth: an integrated approach, Wadsworth

Publishing, London

Mols, C.M.M., andVisser, M. E. (2002) ‘Great Tits can reduce caterpillar damage in

apple orchards’ Journal of Applied Ecology 39, pp. 888–899

Monbiot, G. (2004) Feeding Cars, Not People. Available from:

http://www.monbiot.com/2004/11/23/feeding-cars-not-people/ [Last Accessed

28th July 2011]

Moore, N.W. (1967) 'Effects of Pesticides on Wildlife' Proceedings of the Royal

Society of London 167, pp. 128-133

NAS (2008) Understanding and Responding to Climate Change, National Academy

of Sciences

Nissinen, A., Gronroos, J., Heiskanen, E. et al (2007) ‘Developing benchmarks for

consumer-orientated life cycle assessment-based environmental information on

products, services and consumption patterns’, Journal of Cleaner Production, 15,

pp. 538-549

Oreskes, N. (2004) ‘Beyond the Ivory Tower. The Scientific Consensus on Climate

Change’ Science 306, pp. 1686

PAN (2010) Pesticides and the loss of biodiversity. Available online: http://www.pan-

europe.info/Campaigns/biodiversity.html [Last Accessed 2nd August 2011]

85

Phelan, P. L., Norris, K. H., and Mason, J. F. (1996) ‘Soil-management history and

host preference by Ostrinia nuhilalis: Evidence for plant mineral balance

mediating insect-plant interactions’. Environmental Entomology 25, pp.1329–

1336

Pimentel, D. & Giampietro, M. (1994) Food, Land, Population and the US Economy,

Carrying Capacity Network

Pimentel, D., Hepperly, P., Hanson, J. Douds, D. & Seidel, R. (2005) ‘Environmental,

energetic and economic comparisons of organic and conventional farming

systems’ Bioscience 55, pp. 573-582

Pimentel, D., Hepperly, P., Hanson, J., Douds, D., and Seidel, R. (2005)

‘Environmental, energetic, and economic comparisons of organic and

conventional farming systems’, BioScience 55, pp. 573–582

Pimm, S.L., Russell, G.J., Gittleman, J.L. & Brooks, T.M. (1995) ‘The future of

biodiversity’, Science 269, pp. 347-350

Plassmann, K. & Edwards-Jones, G. (2009) Where does the carbon footprint fall?

Developing a carbon map of food production, Sustainable Markets Discussion

Paper Number 4, Bangor University, Bangor

Pratt, K. and Moran, D. (2010) ‘Evaluating the cost-effectiveness of global biochar

mitigation potential’, Biomass and Bioenergy, 34, pp.1149-1158

Pretty, J. (2001) Some benefits and drawbacks of local food systems. Available from:

http://www.sustainweb.org/pdf/afn_m1_p2.pdf [Last Accessed 30th July 2011]

Pretty, J. N., Ball, A. S., Xiaoyun, L., and Ravindranath, N. H. (2002) ‘The role of

sustainable agriculture and renewable-resource management in reducing

greenhouse-gas emissions and increasing sinks in China and India’ Philosophical

Transactions of the Royal Society 360, pp. 1741–1761

86

Pretty, J.N., Brett, C., Geec, D., Hine, R.E. et al (2000) 'An assessment of the total

external costs of UK agriculture', Agricultural Systems 65, pp. 113-165

Rees, W.E. (1992) ‘Ecological footprints and appropriated carrying capacity: what

urban economics leaves out’ Environment & Urbanization 4, pp. 121-130

Reganold, J., Elliott, L., and Unger, Y. (1987) ‘Long-term effects of organic and

conventional farming on soil erosion’ Nature 330, pp. 370–372

Rejmanek, M. & Randall, J.R. (1994) ‘Invasive alien plants in California: 1993

summary and comparison with other areas in North America’, Madroño 41, pp.

161-171

Reynolds, P.J. (1979) Iron-Age Farm, The Butser Experiment, British Museum

Publications, London

Roberts, P. (2004) The End of Oil. The decline of the petroleum economy and the rise

of a new energy order, Bloomsbury Publishing, London

Röös, E., Sundberg, C. & Hansson, P.A. (2011) ‘Uncertainties in the carbon footprint

of refined wheat products: a case study on Swedish pasta’ International Journal of

Life Cycle Assessment, 16, pp. 338-350

Rundl¨of, M., Bengtsson, J., and Smith, H. G. (2008) ‘Local and landscape effects of

organic farming on butterfly species richness and abundance’. Journal of Applied

Ecology 45, pp. 813–820

Saunders, C. & Barber, A. (2008) ‘Carbon footprints, life cycle analysis and food

miles: global trade trends and market issues’, Political Science, 60, pp. 73-88

Scarre, C. (2005) The Human Past, Thames and Hudson, London

Schnepf, R. (2004) Energy Use in Agriculture: Background and Issues, Congressional

Research Service, The Library of Congress

87

Scialabba, N.E-H. & Müller-Lindenlauf, M. (2010) ‘Organic agriculture and climate

change’, Renewable Agriculture and Food Systems, 25, pp. 158-169

Scottish Water (2010) Scottish Water carbon footprint report 2008-2009. Available

from:

http://www.scottishwater.co.uk/portal/page/portal/SWE_PGP_NEWS/SWE_PGE

_NEWS/INFO_CLIM_CHANGE/Scottish%20Water%20Operational%20Carbon

%20Footprint%202008-09.pdf [Last Accessed 4th August 2011]

Searchinger, T., Heimlich, R., Houghton, R.A. et al (2008) ‘Use of U.S. Croplands for

Biofuels Increases Greenhouse Gases Through Emissions from Land-Use Change’

Science 319, pp. 1238- 1240

Siegle, L. (2011) ‘Chris Young’s innovation: bread matters’ The Observer, 27th

February 2011

Simmons, M.R. (2006) Twilight In The Desert: The Coming Saudi Oil Shock and the

World Economy, John Wiley and Sons, London

Skinner, J.A., Lewis, K.A., Bardona, K.S., Tucker, P., Catt, J.A. & Chambers, B.J.

(1996) 'An Overview of the Environmental Impact of Agriculture in the UK,'

Journal of Environmental Management, 50, pp. 111-128

Smith, P., Martino, D., Cai, Z., Gwary, D. et al (2008) ‘Greenhouse gas mitigation in

agriculture’, Philosophical Transactions of the Royal Society, 363, pp. 789-813

Soil Association (2003) Organic farming, food quality and human health. Available

from

http://www.soilassociation.org/Whyorganic/Health/Reports/tabid/388/Default.asp

x [Last Accessed 27th July 2011)

Soil Association (2007) One Planet Agriculture. Preparing for post-peak oil food and

farming future. The case for action, Soil Association, Bristol

88

Soil Association (2008) An inconvieneant truth about food – neither secure nor

resilient. Available from:

http://www.soilassociation.org/LinkClick.aspx?fileticket=EttWlupviYA%3d&tabi

d=387 [Last Accessed 1stAugust 2011]

Soil Association (2010) Organic Market Report 2010. Available from

http://www.soilassociation.org/LinkClick.aspx?fileticket=bTXno01MTtM=&tabid

=116 [Last Accessed 28th July 2011]

Stalenga, J., and Kawalec, A. (2008) ‘Emission of greenhouse gases and soil organic

matter balance in different farming systems’. International Agrophysics. 22, pp.

287–290

Stavi, I and Lal, R. (2010) ‘Challenges and Opportunities of Soil Organic Carbon

Sequestration in Croplands’. In Lichtfouse, E. (ed) Biodiversity, Biofuels,

Agroforestry and Conservation Agriculture, Sustainable Agriculture Reviews 5,

pp. 149-174

Steffen, W., Sanderson, A., Tyson, P.D., Jager, J. et al (2005) Global Change and the

Earth System: A Planet Under Pressure, Springer, Berlin

Stolze, M., Priorr, A., Haring, A. & Dabbert, S. (2000) The Environmental Impacts of

Organic Farming in Europe, University of Hohenheim, Stuttgart

Suh, S. & Huppes, G. (2005) ‘Methods for Life Cycle Inventory of a Product’,

Journal of Cleaner Production, 13, pp. 687-697

Sullivan, P. (2002) Drought Resistant Soil. ATTRA, National Center for Appropriate

Technology USDA. http://attra.ncat.org/attra-pub/PDF/drought.pdf [Last

Accessed: 10th August 2011]

Sundkvist, A., Jansson, A. & Larsson, P. (2001) ‘Strengths and limitations of

localizing food production as a sustainability building strategy – an analysis of

89

bread production on the island of Gotland, Sweden’ Ecological Economics, 37,

pp. 217-227

The Scottish Government (2011) Modelling Greenhouse Gas Emissions from Scottish

Housing: Final Report. Available from

http://www.scotland.gov.uk/Publications/2009/10/08143041/11 [Last Accessed

9th August 2011]

The Times (2008) Fear of rice riots as surge in demand hits nations across the Far

East. Available from

http://business.timesonline.co.uk/tol/business/industry_sectors/consumer_goods/ar

ticle3701347.ece [Last Accessed 28th July 2011]

Thomas, M. B., and Reid, A. M. (2007) ‘Are exotic natural enemies an effective way

of controlling invasive plants?’ Trends in Ecology and Evolution 22, pp. 447–453

Watkins, T. (2005) ‘From foragers to complex societies in south-west Asia’ In Scarre,

C. (ed) The Human Past, Thames and Hudson, London

Weibull, A. C. & and Ostman, O. (2003) ‘Species richness in agroecosystems: The

effect of landscape, habitat and farm management’. Biodiversity and Conservation

12, pp. 1335–1355

Westerman, P. S., Wes, J. S., Kropff, M. J., and van der Werf, W. (2003) ‘Annual

losses of weed seeds due to predation in organic cereal fields’. Journal of Applied

Ecology 40, pp. 824–836

White, R. (2007) ‘Carbon Governance from a Systems Perspective: an investigation

of food production and consumption in the UK’. In EC (eds) Proceedings,

European Council for an Energy-Efficient Economy 2007 Summer Study, France.

Available from

http://www.eci.ox.ac.uk/research/energy/downloads/eceee07/white.pdf [Last

Accessed 27th July 2011]

90

Whitley, A. (2009) Bread Matters: The state of modern bread and the definitive guide

to baking your own, Andrews McMeel Publishing,

Whittle, A. (1999) ‘The Neolithic period, c. 4000-2500/2200 BC: changing the

world’. In. Hunter, J. & Ralston, I. (eds) The Archaeology of Britain: An

Introduction from the Upper Paleolithic to the Industrial Revolution, Routledge,

London

Williams, A.G., Audsley, E. and Sandars, D.L. (2006) Determining the environmental

burdens and resource use in the production of agricultural and horticultural

commodities, Main Report, Defra Research Project IS0205, Cranfield University

and Defra, Bedford

Williams, A.G., Audsley, E. and Sandars, D.L. (2010) ‘Environmental burdens of

producing bread wheat, oilseed rape and potatoes in England and Wales using

simulation and system modelling’ International Journal of Life Cycle Assessment,

15, pp. 855-868

Williams, H. & Wikstrom, F. (2011) ‘Environmental impact of packaging and food

losses in a life cycle perspective: a comparative analysis of five food items’,

Journal of Cleaner Production, 19, pp. 43-48

Woods, J., Williams, A., Hughes, J.K., Black, M. & Murphy R. (2010) ‘Energy and

the food system’ Philosophical Transactions of the Royal Society, 365, pp. 2991-

3006

World Commission on Environment and Development (1987) Our Common Future,

Oxford University Press, Oxford

WRAP (2008) The Food We Waste, WRAP, Banbury

Zhu, Y., Chen, J., Fan, J., Wang, Y. et al (2000) ‘Genetic diversity and disease control

in rice’, Nature 406, pp. 718-722