The Greenhouse Inventory of the Province of Siena

The Greenhouse Gas Inventory of the Province of Siena

M. ~neller ' , L. ~ u ~ a r o * & N. ~ a r c h e t t i n i ~ I Lamont Doherty Earth Obsewatoiy, Columbia University, U.S.A. and Department of Earth Sciences, University of Siena, Italy 2 Department of Chemical and Biosystem Sciences, University of Siena, Italy

Abstract

As a result of increasing warnings by members of the scientific community about the possible harmful effects of rising greenhouse gas concentrations, the Intergovernmental Panel on Climate Change (IPCC) was established by the World Meteorological Organization and the United Nations Environment Programme in 1988, in order to assess the available scientific, technical, and socioeconomic information concerning possible future climate change. The aim of our project is to use the "Revised 1996 IPCC Guidelines for National Greenhouse Gas Inventories," in order to conduct a Greenhouse Gas Inventory for the province of Siena. This will quantify greenhouse gas sources and sinks at a local (provincial government) level. The inventory will be useful when governing bodies discuss community planning, where that planning may have an impact on the size of the sources and sinks. We conducted our inventory with data from the years 1999 and 2000. The Siena province emitted 1818 Gg (gigagrams) of CO2 into the atmosphere in the year 1999, due to the combustion of fossil fuels for energy purposes. The major contributors to this emission are natural gas, diesel fuel, gasoline and blended fuel oil, in descending order of importance. A significant portion of the COa derives from combustion outside the province, by the national electric power provider. However, the large presence of rural areas and woods within the Siena province contributes to a calculated CO2 sequestration of approximately 11 19 Gg CO2. Global Warming Potentials of the greenhouse gases are utilized: the net result is that the forests may balance approximately 60% of the greenhouse gas arising from the

Transactions on Ecology and the Environment vol 64, © 2003 WIT Press, www.witpress.com, ISSN 1743-3541

province's fossil fuel usage and the methane produced by its solid waste disposal sites.

l Background: The Kyoto Protocol and greenhouse gases

In 1990 the United Nations established the Intergovernmental Negotiating Committee for a Framework Convention on Climate Change. At its Third Conference of the Parties in Kyoto, Japan, December 1997, representatives from more than 160 nations negotiated binding limitations on greenhouse gases for the developed nations. The outcome of the meeting is the Kyoto Protocol, in which the developed nations agreed to limit their greenhouse gas emissions, relative to the levels emitted in 1990. The individual targets for the Annex I countries range from an 8% reduction for the European Union to a 10% increase for Iceland. The greenhouse gases included are carbon dioxide, methane, nitrous oxide, hydrofluorocarbons, perfluorocarbons, and sulphur hexafluoride. For the latter three gases, nations have the option of using 1995 as the base year from which to achieve reductions, instead of 1990. The aggregate target is established using the carbon dioxide equivalent of each of the greenhouse gases [l].

The established targets must be achieved over the period 2008 to 2012, the first commitment period. Each country must have made demonstrable progress by 2005. Sources of emissions include fuel combustion, fugitive emissions from fuels, industrial processes, solvents, agriculture, and waste management and disposal. The Protocol does not prescribe specific actions to be taken but lists a number of potential actions, including energy efficiency improvements, enhancement of carbon-absorbing sinks, such as forests and other vegetation, research and development of sequestration technologies, phasing out of fiscal incentives and subsidies that may inhibit the goal of emissions reductions, and reduction of methane emissions in waste management and in energy production, distribution, and transportation.

Initially, the study of greenhouse gases has focused on the CO2 cycle. The anthropic impact upon tropospheric CO2 concentrations became apparent following the measurements made by Charles Keeling. In 1959 the average atmospheric concentration of CO2 was 315.98 ppmv, rising to 370.9 ppmv in 2001 [l]. The rate at which terrestrial ecosystems and the ocean will absorb the CO2, initially emitted by fossil fuel burning, remains uncertain.

Instrumental temperature records show a surface temperature warming of between 0.65"C to 0.92OC per century, since 1860. Several other findings are important in order to understand the significance of this warming trend. First, the rate of temperature increase since 1976 has increased, to over 0.15"CIdecade. 1998 was the warmest year on record, and 2001 the second warmest; the 1990s were the warmest decade on record [2]. This warming is considered to be a consequence of anthropogenic greenhouse gases [3]. Second, a 0.6"C temperature change may appear small, however the surface temperature difference between the present, and full ice-age conditions of 21,000 years ago, is currently estimated at between just 3.0 and 5.0°C. This 3.0 to 5.0°C temperature difference accompanied the expansion of continental ice sheets, up


to 3000m thick, which covered the mid-latitudes of North America to New York City, and much of England and Scandinavia with ice up to 2500 m thick. Third, the globally averaged temperature change of 0.6"C, is accompanied by much larger regional and seasonal temperature changes. Over much of the land in the temperate latitudes of the northern hemisphere, winter temperatures have increased by 1°C per decade. In the summer, the warming trend over almost all of the western Eurasian continent is 1°C per decade.

2 The IPCC methodology

We are following the "Revised 1996 IPCC Guidelines for National Greenhouse Gas Inventories (hereafter referred to as Revised Guidelines)" which were accepted by the Intergovernmental Panel on Climate Change (IPCC) at its Twelfth Session (Mexico City, 11-13 September 1996). The Revised Guidelines consist of three volumes: 1. the Reporting Instructions; 2. the Workbook; and 3. the Reference Manual. The processes that produce or absorb greenhouse gases (also referred to as sources and sinks) have been grouped into six categories, which are referred to as Modules. These six modules are: 1. Energy, 2. Industrial Processes, 3. Solvent and Other Product Use, 4. Agriculture, 5. Land-use Change and Forestry, and 6. Waste. By following the instructions in these volumes, Summary Report Tables (which are called worksheets) can be produced with numerical values for the production (sources), or absorption (sinks), of the following Greenhouse Gas Categories: COz Emissions, CO2 Removals, and then the emissions of CH4, N20, NO,, CO, NMVOC (Non methane volatile organic compounds), SO2, HFCs, PFCs, and SF6. The instructions are intended to be utilized at the national level.

Extensive, detailed information is required in order to fill-in the worksheets. Since the information requested is not always available, we have focused our efforts in order to produce a GGI that is both accurate, and relevant. Two recent articles may help us focus our efforts. First, J. Hansen and M. Sato[4], state that "the recent flat growth rate of CO2, despite continuing increase of CO2 emissions at about 1 % 1 year, is in part of a reflection of increased terrestrial sequestration of carbon in the 1990s." Second, R. B. Myneni, Dong, and others[5] present evidence that carbon from fossil fuel emissions is being sequestered in vegetation biomass. Neither of these two results is new and unexpected, but they do show that scientific interest continues to focus on the CO2 emissions, and on the terrestrial vegetation. Recent scientific consensus continues to be that the combustion of fossil fuels is the largest anthropogenic contributor to the greenhouse gases, of which the principal greenhouse gas is COz, followed by methane (CH4), chlorofluorocarbons (CFCs) and nitrous oxide (N20).

At this stage in the SPIn-ECO project, we have focused on the years 1999 and 2000, for which data is now readily available (this is January 2002).


3 Calculation of greenhouse gases, sources and sinks: the IPCC methodology applied to the Siena province and the results

Module 1: energy

We utilised the Revised Guidelines Tier 1 method, Reference Approach, which is essentially an estimate of emissions based upon the carbon content of fuels combusted for purposes of energy production. For Siena Province, we evaluate the carbon content of the fuels that indirectly and directly enter the province: indirect emissions are those resulting from combustion of fossil fuels by the "Rete Nazionale (the national electric grid)" and direct emissions result from combustion of fossil fuels directly within Siena province.

We estimate the amount of indirect emissions by determining the amount of electricity provided by ENEL (the Italian national electric company) to Siena Province; this is electricity that Siena receives from the Rete Nazionale. For the year 1999, Italy consumed 267,284 GWh of energy and Siena province consumed 1027 GWh of energy, or 0.384 %. Thus Siena province is allocated 0.384% of the CO2 emissions emanating from each fossil fuel utilized by the Rete Nazionale.

Italy also imports energy which is then added to the Rete Nazionale: the quantity imported is 56,284 GWh. for the year 1999. In order to calculate carbon emissions from this imported energy, several assumptions have been made. First, the various fuel sources must be identified. 1998 is the most recent year for which we have a breakdown of imported electrical energy, by country and energetic source (Table 1). For 1998, 8.9% of the imported energy is thermoelectric energy. We assume that 8.9% of the 56,284 GWh, which equals 5000 GWh, is thermoelectric in source, until more information becomes available. Second, we have approximated its Carbon Emission Factor as 20 t C/TJ (see Table 1-2 of the Revised Guidelines, Workbook).

Fuels combusted within Siena province are called direct emissions. We estimated sales of gasoline, diesel oil, other diesel fuel, LPG, lubricants, and blendedhunker fuel oil, occurring within the province, from compilations of the Ministero dell'lndustria, del Commercio e dell'Artigiano (MICA, Ministry of Industry, Commerce and Artisans). Natural gas sales (also called gas metano) are derived from the distributors to the manufacturing, service, and civilian sectors. Table 2 contains the key energy data, and the calculations in order to achieve the "Actual CO2 Emissions".

Table l : Imported electrical energy for the year 1998, source: ENEL.

Country

France Switzerland Austria Former Yugoslavia Total

Net Import (GWh)

16 100 21 500

1 630 1 500

40 730

Imported energy from thermoelectric sources

("/.l 8 4

34 60

Thermoelectric Energy imported (GwM

1 300 860 550 900

3 610


Table 2: CO2 from energy resources (reference approach), year 1999, Revised Guidelines Worksheet 1-1.

I** Conversion factors from Table 1-2, Workbook, except natural gas where it comes from http:l/bioenergy.oml.govlpape~~/misc/ener~-conv.h~


Siena Province emitted 1818 Gg (gigagrarns) of CO2 into the atmosphere in the year 1999, due to the combustion of fossil fuels for energy purposes. The major contributors to this emission are natural gas, diesel fuel, gasoline and blended fuel oil, in decreasing order of importance. If one evaluates only the direct fuel emissions, then the major contributors are natural gas, diesel fuel and gasoline.

Module 2: industrial processes

The industries of Siena are mainly agricultural, and tourism-based and thus many of the IPCC industrial processes are not relevant. However, the production of red wine, white wine, and spirits generates NMVOCs. Siena province is known for its wine production, thus we have made a calculation of the NMVOCs (Table 3) produced from this activity based on statistics from ISTAT.

Table 3: Alcoholic beverage production-NMVOC emissions, Revised Guidelines Worksheet 2- 13.

1 Ouantitv in h1 I Emission Factor I NMVOCs emitted 1 NMVOC

A small quantity, 0.0504 Gg, of NMVOCs are produced from wine production within the province. In the remaining years of the SPIn-ECO project we will identify those few industries in Siena that may have some significant contribution to greenhouse gas emissions.

<l00 litres) 1 (kgNMVOC1100 1) I

Module 3: solvent and other product use

(Gg)

This is a small module. The activities include paint application, degreasing and dry cleaning, and chemical products, manufacturing and processing. The greenhouse gases emitted are CO2, N20, and NMVOCs. We have not collected data for these activities and obtaining the quantities of solvents used at the provincial level will be difficult.

630 000 1 0.08 1 50 400 1 0.0504

Module 4: agriculture

The processes relevant to the Siena province will be: 1. Methane (CH4) emissions from domestic livestock enteric fermentation and manure management, 2. Methane and Nitrous oxide emissions from domestic livestock enteric fermentation and manure management, 3. Field burning of agricultural residues, and 4. Agricultural Soils (specifically fertilisers used and nitrogen- fixing crops). Data is presently not available for the last three categories.

We presently have data to calculate CH4 emissions from domestic livestock enteric fermentation and manure management. Table 4 contains the calculations of CH4 emissions for the year 2000. The number of animals come from the 5" Censimento Generale dell'Agricoltura 2000 (General Census, year 2000). The


following approximations were made: 1. the 14,142 "Bovini e/o Bufalini," were given a 25:75 partition between Dairy Cattle and Non-Dairy Cattle (dairy cattle produce significantly more methane than non-dairy cattle); 2. the 125,601 head of "Ovini e/o Caprini," were given a 90:lO partition between sheep and goats; 3. poultry is not included in the census, we have hypothesized 10,000 birds for the province.

Table 4: Methane emissions from domestic livestock enteric fermentation and manure management, Revised Guidelines Worksheet 4-1.

Thus the relevant emissions from domestic livestock are 2.55 Gigagrams of methane for the year 2000.

Mules & Asses Swine Poultry Total

Module 5: land use change and forestry

The IPCC Executive Summary states that this is an area with high potential for scientific interest, and highly relevant to national policy, because forests and soils can sequester COz, and management of the local forests will directly affect the quantity of CO2 sequestered. Items for the GGI include: 1. Changes in Forest and other Woody Biomass Stocks, 2. Forest and Grassland Conversion, 3. On- Site Burning of Forests, 4. Abandonment of Managed Lands, and 5. Soil Carbon. Essentially, the Siena Province must attempt to measure the annual (or perhaps decadal) incremental change of woody biomass, whether that woody biomass is in protected forests, plantations, commercial timber, or in urban areas. The activities above, when summed, can produce either a net source, or sink, of COz. The Revised Guidelines acknowledge that "there are inherently large uncertainties or errors associated with these calculations."

We currently have partial information for item 1 above. The following are the key assumptions underlying the calculations. First, the area that is "forest" for this Bilancio Serra is that classified as "boschi (woods)" and "arboricoltura

23.7 10.0

1.5 35.55 ----p-p

10.00 1910.95

0.27 0.01 2.55

10.00 0.12

237.00 1.17

642.65


da legno (arboriculture for timber)" according to the 5" Censimento Generale dell'Agricoltura (General Census of Agriculture) (2000). "Woods" are defined as "those areas covered with trees or forest shrubs, in which wood is the principal product. Woods includes forested terrain in which the soil is partially utilised for herbaceous cultivation at a limited scale, and tree seedlings nurseries for company needs. Chestnut woods and poplar-groves are excluded. "Arboriculture for timber" includes "chestnut woods and poplar-groves, and terrain with fruit- bearing trees that are destined for timber, not fruit, production (e.g. walnut, cherry, plum, and eucalyptus trees, etc.). We exclude from the total of "forest" hectares those identified as "coltivazioni legnose agrarie (miscellaneous woody agriculture)," which are those hectares being utilised for grape vines, olive trees, citrus trees, fruit-bearing trees, seedlings in nurseries, reeds, mulberry-trees, rushes, manna, wicker willows, and summack-that is terrain which does not have a continuous crown cover. Second, we have estimated the "annual growth rate" at 5 tonnesldry matterlhectarelyear: this is the mean of the only two values given for temperate tree species (Pseudotsuga taxifolia and Pinus taeda) in the IPCC Guidelines (Table 5- 1, Workbook). The IPCC Guidelines state that these values are based upon measurements in the United States and that data from other regions should be supplied by individual countries. The third assumption is the "carbon fraction dry matter," which has a default value of 0.5 if specific values are not available. The fourth simplifying assumption is that the amount of biomass harvested (for commercial harvest and fuel wood) is essentially zero. This assumption is not accurate since there is cutting for fuel wood, and in the future the losses and gains in forested area should be evaluated.

Table 5: Changes in forest and other woody biomass stocks, Revised Guidelines

Forest Annual Annual Carbon Total Total Growth Biomass Fraction Carbon Biomass

(t d m h ) (kt dm) Matter (kt C) or Removal

610.5 1119

The forests in Siena province sequestered approximately 11 19 Gg CO2 in the year 2000. The ratio of "total carbon uptake" to "forest area" (305.25 : 122.1) is + 2.5 tonneslyear. Valentin and others [6] show that most European forests act as carbon sinks: data from 27 European sites shows the carbon absorbed varies from + 6.6 to - 1 tonnes carbonlhectarelyear. Therefore the estimate for the forests in Siena province is within the range of expected values.

To improve the estimate of COz sequestration, we must collect the following information: 1. annual changes in forested area; 2. composition of forest, and 3. the ages of the forests in the Siena province. Soil type should also be included, since it will impact the amount of sequestered COz.


Module 6: waste

Anaerobic decomposition of organic mater by methanogenic bacteria in solid waste disposal sites releases CH4 to the atmosphere. This source is estimated to account for about 5-20% of global anthropogenic CH4 emissions.

We have data for 1999 from the Ossewatorio provinciale dei rifiuti della Provincia di Siena (Siena provincial observatory of waste materials) which we used to approximate CH4 production from solid waste disposal sites. We have assumed that the fraction of degradable organic carbon in the waste collected is 10%. We calculate 5.2 X 10'~ Gg of methane generated in 1999.

Table 6: CH4 from solid waste disposal, Revised Guidelines Worksheet 6-1.

Total Annual

Solid Factor Waste

Fraction Potential Carbon C b released Generation as CH4 Rate

Gross generated Annual

waste Generation (Gg CH41

MSW)

The estimate of Cl& emissions is sensitive to the percent degradable organic carbon of the wastes, and this estimation should be checked.

4 Summary of greenhouse gases and Global Warming Potential

To provide a simple common measure of the radiative forcing of each greenhouse gas, a Global Warming Potential (GWP) can be utilized. The GWP is the ratio of the effective radiative forcing of a certain gas, with respect to a like mass of CO2. Convention gives CO2 a GWP of one, whereas for example CH4 has a GWP of 23 (for the time horizon of 100 years) [7] . The GWP values are still under scientific discussion; NMVOCs have as yet no assigned GWP. A summary of the GGI and the calculated GWP for each emission category (Table 7) shows that Siena province emitted a CO2 equivalent of +l877 Gg, sequestered 11 19 Gg of CO2, summing to a net CO2 equivalent emission of +758 Gg C02.

5 Conclusions

The GGI conducted at the small provincial scale is unique for trying to quantify the greenhouse gas sources and sinks at the local scale. The GGI can then be utilised when proposing political and economic decisions at the local (provincial) level, that may have an impact on greenhouse warming. The methodology followed here may be repeated for the years 1990 through 2000, in order to assess the annual variability and trend in the GGI.


Table 7: Greenhouse Gas Inventory for Siena Province, data from 1999 and 2000.

Greenhouse Gas Source or Sink

CO1 indirect emissions (energy from the Rete Nazionale) COn direct emissions (fuel

Mass Emitted(+) or Absorbed(-)

cornbusted in the province) NMVQCs from wine production C& emissions from domesticated

C@ Equivalent Siena Province

(Gd +772.64

+1045.76

livestock COz sequestered by forests CH4 emissions from municipal

In 1999, Siena Province consumed a total of 1027 GWh from the Rete Nazionale. However, because of its extensive geothermal energy resources, the province also produced 933 GWh of electrical energy, which was contributed to the Rete Nazionale. Thus Siena Province potentially satisfies approximately 90% of its electrical requirements from non fossil-fuel resources. The electrical energy that the Siena Province supplies to the Rete Nazionale, via the production of geothermal energy, is relatively low in CO2 emissions.

Total emissions of greenhouse gases from the combustion of fossil fuels, for heating and transportation, in addition to electricity from the Rete Nazionale, produced 1818 Gg CO2 in 1999. A significant portion of these are direct emissions (1046 Gg), within the province; it is here that local patterns of energy usage can be evaluated, in order to determine where reductions in emissions are possible. One possibility is to examine the trends in natural gas consumption (primarily for heating), and in gasoline consumption (primarily for transportation), in order to show where energy efficiency is increasing, and where it is decreasing.

The rural areas and woods may absorb approximately 60 % of the greenhouse gas emissions. Thus the province's woods are invaluable in balancing the CO2 emissions from fossil fuels.

(Gd +772.64

+1045.76

4.0504 +2.55

solid waste

References

not available +S8.6

-1119 +0.0052

I

[ l ] Keeling, C. D. & Whorf, T.P. Atmospheric carbon dioxide record from Mauna Loa. http://cdiac.esd.ornl.gov/trends/co2/sio-mlo.htm.

[2] Hansen, J., Reudy, R., Sato, M. & Lo, K. Global warming continues. Science, 295, p. 275.

[3] Houghton, J. T. & others (eds). IPCC, 2001: Climate Change 2001: The Scient@c Basis. Contribution of Working Group I to the Third Assessment Report of the Intergovernmental Panel on Climate Change, Cambridge University Press: Cambridge, United Kingdom and New York, 2001.

-1119 +0.119

Net Source +758 J


[4] Hansen, J. & Sato, M. Trends of measured climate forcing agents. Proceedings of the National Academies of Science, 98, pp. 14778-14783, 2001, and at www.pnas.org/cgi/doi/10.1073/pnas.261553698.

[5] Myneni, R. B., Dong, J., Tucker, C. J., Kaufmann, R. K., Kauppi, P. E., Liski, J., Zhou, L., Alexeyev, V. & Hughes, M. K. A large carbon sink in the woody biomass of Northern forests. Proceedings of the National Academies of Science, 98, pp. 14784-14789, 2001 and at www.pnas.org/cgi/doi/10.1073/pnas.261555198.

[6] Valentin, R., Matteucci, G., Dolman, A. J., Schulze, E. - D. & others. Respiration as the main determinant of carbon balance in European forests. Nature, 404, pp. 861-865.

[7] Rarnaswamy, V. and others. Radiative forcing of climate change (Chapter 6). IPCC, 2001: Climate Change 2001: The Scientific Basis. Contribution of Working Group 1 to the Third Assessment Report of the Intergovernmental Panel on Climate Change, eds. Houghton, J . T. & others Cambridge University Press: Cambridge, United Kingdom and New York, pp. 349416,2001.


The Greenhouse Inventory of the Province of Siena

Documents

Transcript of The Greenhouse Inventory of the Province of Siena