Livestock and greenhouse gas emissions

Exploring the relationshipTara Garnett

Food Climate Research Network7 December 2007

About the FCRN – some context

Funded by UK research council & based at Surrey UniversityFocuses on:• Researching food chain contribution to

GHG emissions and options for emissions reduction

• Sharing and communicating information on food & climate change with member network

FCRN outputs

1. Four comprehensive studies so far:1. Fruit & vegetables2. Alcoholic drinks3. Food refrigeration4. Meat & dairy

2. Working seminars: To inform research3. Mailings: regular news on food / GHGs to

670+ members4. Networking: To catalyse further research

Presentation today1. Trends production & consumption2. Review of livestock-related studies3. GHGs associated with system inputs 4. GHGs associated with system outputs5. Mitigation options 6. Scenarios

7. Conclusions

Largely but not solely UK focused

Limitations

• Focus on GHGs and not other environmental impacts

• Up to farm gate only (although leather, wool and rendering upstream impacts)

• More on cattle than the other livestock• No economic analysis – planned for future

study

Overall food-related contribution to GHG emissions

• EU EIPRO report: 31% all EU consumption related GHGs

• FCRN UK estimates: around 19% (probably an underestimate)

• Defra estimates similar

Food consumption related contribution to UK consumption GHGs (work in progress)

1. CONSUMPTION TRENDS

UK consumption - meat

UK consumption – dairy ex milk

Milk consumption declining

Projected global trends in demand

Global meat demand by animal type

2020

1997

Source: IFPRI 2001

Policy influences

2. REVIEW OF LIVESTOCK GHG CONTRIBUTION

Livestock GHG estimates

• Global – 18% (FAO)

• EIPRO – 15% (half all food impacts)

• Dutch study: half all food impacts

• UK (from this study):– 6.6% production related GHG emissions

(NETCEN & other)– 8% consumption emissions (Cranfield plus

volumes based on MLC & Defra)

But

• Livestock production yields food and non food benefits – they ‘save’ having to produce them by other means

• Make use of unproductive land & byproducts

• We have to eat – there’ll always be an impact

• Would non-animal substitutes be any better for GHG emissions?

To understand why the impacts arise and how/whether they can be reduced you need to look at

• The inputs to livestock production and GHG implications

• The outputs and GHG implications

3. THE INPUTS

The inputs

• Cereals: How much? Alternative uses (food, biofuel)?

• Oilseeds: Second order impacts? Relationship between cake and oil?

• Grazing land: Inputs to? Alternative uses? Benefits of?

• Byproducts: Alternative uses? • Land: What’s the best way of using

the land for most output at least GHG cost?

• Energy: not discussed

• What are the second order impacts?

• What is the opportunity cost – could these inputs be used in other ways?

Cereals

• UK: 50% wheat; 60% barley • Globally: 33 – 37% cereals• Cattle 50% feed cereals; pigs & poultry

50%• Alternative uses?

– Direct human consumption (quality – wheat grades? Nutritional comparability with meat?

– Biofuels?

Oilseeds - soy• Soy – 40% oilseeds in livestock diet (av)• By- or co-product?

– Soy volume: 20% oil 80% cake– Soy value: 33% oil 67% cake

• Feed cake drives soy production – now biofuels too

• Implications?– Human diet– Lost carbon sequestration – 2nd order impact

Human diet: oilseed consumption

Soy – lost carbon sequestration

• Brazilian soy 60% EU imports• Legal Amazonia – Cerrado & rainforest• Direct & indirect deforestation• Direct: doubling of soy cultivation in last

decade and could double again • Indirect: push other industries onto land• Plus of course Brazilian cattle ranching• Lost C sequestration not captured in

standard LCA

Former forest, Matto Grosso Brazil

Byproducts

• Livestock make use of byproducts – resource utilisation

• How much production do byproducts actually sustain?

• Could these byproducts be used for something else? Opportunity cost?

• Quality of feed / methane?• Are they byproducts produced near where

they’re needed?

Grassland

• 37% agric land used for grazing• Grass not a free resource – fertiliser

inputs & significant N2O emissions• Overgrazing globally - FAO estimates this

accounts for 7% global GHG emissions• Some overgrazing in the UK and also

undergrazing

Grassland continued

• Carbon sequestration: appropriate grazing makes sequestration pay BUT losses if overgrazed)

• Alternative use: biomass cultivation? If:– Price is right– No disruption to soil (C losses)

• Or forest cover

Land: the big issues....

• Need to consider the opportunity cost of using land for one purpose over another– Land to feed animals or to feed humans? – Land for feed production or for C

sequestration?– Land for animal rearing or for biomass

production?• Bearing in mind projected 9 billion by 2050

4. THE OUTPUTS

Livestock: The outputs

• Nutrition: protein, calcium, iron, B12, fat…• Leather & wool• Rendered products: glues, soaps, pet

food…• Manure: nutrients and soil quality• Soil carbon sequestration• Landscape aesthetics & biodiversity

Questions

• What benefits do we gain from livestock production?

• Are these benefits accurately accounted for in life cycle analysis?

• How much do we need these products?– (who defines need?)

• To what extent can we obtain these goods / services by non livestock means and what would the GHG implications be?

Nutrition

Protein

• Global av 28.7 g protein a day* (ie. pure protein not grams of meat or milk)

• Devpg world 21 g a day

• Developed world: 20% kcal from animal products

• Developing world: 6%

Calcium, Iron & B12

• Dairy products good sources of calcium – non meat alternatives available

• Red meat good sources of iron – non meat sources available – anaemia global problem

• B12 – sources animals, yeast and (now) fortification

General conclusions on meat, dairy and nutrition

• Good source of calcium, iron & Vit B12• Not so important for protein• Provides fat in excess• Livestock products not essential• But useful in small quantities esp. for

vulnerable groups• Issues in developed world and extremely

poor in developing world different

Other benefits: leather and wool

• Leather : useful byproducts but not ‘needed’ at current levels (but devpg world industries)

• Comes with own environmental downsides

• Wool: v. small textile player

Non-carcass & rendered products• Are we making the best use of the carcass?

– Decline in offal consumption– Trading of unwanted parts– Pet food... (do we need to feed them all this?)– Oleochemicals– Energy – Some waste

• Are there ways of consuming which would enable lower livestock production levels?

• Post-BSE disposal problems – future risks?

Manure

• Costs & benefits– Avoids need for mineral fertilisers (although

harder to optimise input levels)– Contributes to soil quality / carbon

sequestering properties of soil– Leads to methane and N2O emissions

• Manure isn’t necessarily where you want it• Fertiliser needed in first place to support

animal feed production

Soil carbon sequestration

• Overgrazing and undergrazing

• Not relevant to all livestock types

Biodiversity & aesthetics

• Importance of grazing to biodiversity• Overgrazing and decline in biodiversity• 20% land degraded worldwide (73% in dry

areas)• Overgrazing more of a problem than

undergrazing (though this may change)• Grazing land in UK - biological interest?• Aesthetics: We like what we know... Not a

question of all or nothing

5. MITIGATION

Relative importance of different gases - GWP

Source: Williams AG (2007) per comm. Based on 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.

Mitigation options

1. Husbandry

2. Changing management

3. Managing outputs

4. Changing numbers

• Need to consider all gases – pollution

swapping risk

• Framing issues: Animal welfare, biodiversity, long term soil quality, rural economy

• Trade offs inevitable: With other social / environmental concerns & pollution swapping

1. Husbandry for productivity• Modifying diet:

– Concentrates – High sugar grasses– Legumes– Nutritional supplements

• Animal breeding: for productivity / longevity / multifunctionality

• Animal welfare & biodiversity?• 2nd order C impacts of high cereal diet?

2. Changing management

• Soil inputs: reduce N inputs, soil management, maximise N efficiency

• Intensive vs extensive: extensive more nitrogen efficient?

• Organic vs non organic: Studies mixed – long term soil fertility / C storage potential? System vs individual differences?

• Housing: Manure management but animal welfare?

3. Managing outputs

• Manure: AD• Slurry and FYM heap management

4. Changing numbers

• Simplest ...and hardest

Key issues

• What do we decide to use our land and other resources for?

• Need to bear projected 9 billion population in mind

• And an 80% (more?) required cut in emissions...

• Tackle problems in isolation or as a whole - atomised vs synthetic approach?

6. SCENARIOS

The scenarios

• Business as usual• Maximum productivity• Organic• Intensive plus extensive• Livestock switching• Marginal livestock rearing• NEED TO CONSIDER: other sustainability

& welfare objectives; second order impacts; land opportunity cost

Maximum ProductivityGHG reduction UK reduction but not elsewhere

Impact on human nutrition Nutritionally enhanced meat etc – otherwise little difference

Impact on non food goods Little impact – slight reduction

Rural economy Little impact – gains for niche farmers producing nutritionally enhanced products

Soil fertility N surplus risk

Biodiversity Most ruminant on biologically monotonous pasture. Scope for some species diversity in upland areas

Aesthetics Similar to today but less livestock in uplands

Animal welfare Arguably negative

Land opportunity cost Increased land for biofuels but conflict with land needed for feed? Second order impacts lost carbon sequestration potential on land overseas.

OrganicGHG reduction Reduction on per area basis but not necessarily per yield

(although need to consider carbon storage)

Impact on human nutrition If consumption reduced, possibly good

Impact on non food goods Little impact – slight reduction

Rural economy Depends on CAP etc- if consumers are willing to pay more for organic he impacts could be beneficial

Soil fertility Mixed results; greater use of manure and legume rotations could have a positive effect

Biodiversity Probably good

Aesthetics Depends on the scale but probably positive

Animal welfare Possibly good

Land opportunity cost Less land available for other purposes. Lower reliance on concentrates means land use impacts overseas lower (although organic farming still depends on concentrates).

Intensive & extensiveGHG reduction First order reductions, although second order impacts

unclear and probably negative

Impact on human nutrition Unchanged from current situation; the total output of livestock products may not change very greatly

Impact on non food goods Probably unchanged

Rural economy This depends on CAP and other policy developments, but the impacts could be negative if costs increase relative to current methods.

Soil fertility Possibly positive

Biodiversity No change if standard grass / grass-clover mixes are sown although overgrazing may be reduced.

Aesthetics Little change – some less intensive systems

Animal welfare Extensive systems may benefit animal welfare although management will be key

Land opportunity cost High dependence on concentrates means potentially negative impacts from lost carbon sequestration overseas. Less land available for biofuels production

Livestock switchingGHG reduction Fewer CH4 emissions. Renewable energy could reduce C

intensity of p&p units. Second order impacts negative. Problems could arise from pig and poultry manure surpluses

Impact on nutrition Chicken & (fatless) pork low in fat but less good for Ca & Fe.

Impacts on non food Less leather & wool

Rural economy Negative for ruminant farmers. Mixed for P&P – more competition from more entrants could simply drive prices down.

Soil fertility Possibly negative - fewer livestock to fertilise grass land

Biodiversity Patchy - grazing land can be managed to maximise biodiversity rather than grazing productivity but benefits of grazing lost

Aesthetics Negative in so far as we value seeing livestock grazing

Animal welfare Depends on the rearing system adopted

Land opportunity cost More land needed to grow feed (but cattle eat cereals too). Less available for food / biofuels. Lost sequestration potential.

Marginal livestock rearingGHG reductions More CH4/kg output; N use efficiency might decrease. Feed production

impacts & 2nd order impacts reduced. Overall GHG reduction through number cuts and measures to reduce consumption

Impact on nutrition Consumption would decline– positive but interventions needed to maintain Ca & Fe levels among vulnerable groups. Cattle & sheep main meat .

Impact - non foods Slight reduction in availability

Rural economy Potentially v.damaging unless measures taken to raise the cost of livestock products and increase returns to farmers. Potential for diversifying into other areas eg biocrops

Soil fertility Possibly beneficial. Less manure available for arable land but area needed for arable would decline (since feed cereals cut). Nutrient shortfalls could in part be met from AD digestate and compost.

Biodiversity Depends on management; reductions in overgrazed areas will be good but numbers will need to be maintained in undergrazed areas

Aesthetics Depends on management. If upland areas stocked appropriately then favourable. Some changes may be seen as negative such as an overall decline in the livestock we see on rural land.

Animal welfare Poss beneficial although care is needed to maintain good nutritional health.

Land opp cost Positive - less lost carbon sequestration from overseas feed production. Land could be used for arable or for biofuels.

7. THOUGHTS, QUESTIONS, CONCLUSIONS

What I think is fairly certain

• Livestock impacts significant• Some livestock production positively

beneficial• But not at current levels...• ...Or given current trends• Techno-oriented mitigation approaches

don’t tackle second order impacts• Nor relationship with other sustainability

objectives

And....

• Significant reduction in production and consumption meat AND dairy needed

• We need to pay more for livestock products

• We need to collaborate globally and think strategically about how to make best use of land

In other words

• In the context of 9 billion on planet by 2050• What is the best use of global land so that:

– We are all fed adequately ...– At minimum GHG cost?– Stored carbon is not released?– Biodiversity is protected?– Other ethical non-negotiables upheld??

• Meeting Needs rather than demand - only feasible approach

Thank you

Tara Garnetttaragarnett@blueyonder.co.uk

www.fcrn.org.uk

Food Climate Research Network