Emissions of CH4 and Emissions of CH4 and N2O from Agriculture N2O from Agriculture in Irelandin Ireland

Michael McGettigan,Environmental Protection Agency

Principal Activity DataPrincipal Activity Data

1990 1995 2000

Dairy Cattle thousand head 1356 1262 1231

Other Cattle thousand head 4926 5449 5591

Sheep thousand head 7606 7116 6384

Pigs thousand head 1091 1534 1776

Fertilizer N kt 366 404 427

Organic N kt 444 481 498

Crops thousand ha 416 400 400

Grassland thousand ha 5129 3993 4022

Overall Sector Contribution and Overall Sector Contribution and TrendsTrends

Agriculture accounted for 27.5% of total GHG emissions in 2000 (approx 34% in 1990)

Single largest source is CH4 emissions from enteric fermentation in non-dairy cattle (8.8%)

Direct N2O emissions from organic N higher than from chemical N

Nine key sources in agriculture (3 for N2O and 6 for CH4)

Contribution to national total is decreasing

Component Contributions and Component Contributions and TrendsTrends

0

5000

10000

15000

20000

25000

1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000

Ent Ferm Cattle Ent Ferm Other Manure Mgmt Ag Soils

Key Sources - Emissions IPCC Level Key Sources - Emissions IPCC Level 22

I PCC Level 2 GHG Emissions 2000 Level Cumulative

Source Category in 2000 Assessment Total of Level

Gg CO2 % %

1.A.1 Energy Industries CO2 16621.58 24.81 24.81

1.A.4 Other Sectors CO2 10786.70 16.10 40.91

1.A.3 Transport CO2 10542.31 15.74 56.64

4.A Enteric Fermentation CH4 9664.35 14.42 71.07

4.D Agricultural Soils N2O 6665.76 9.95 81.02

1.A.2 Manufacturing Industries CO2 4904.24 7.32 88.34

2.A Mineral Products CO2 1693.03 2.53 90.87

6.A Solid Waste Disposal CH4 1539.72 2.30 93.16

4.B Manure Management CH4 1395.74 2.08 95.25

2.B Chemical Industry CO2 883.29 1.32 96.57

2.B Chemical Industry N2O 812.45 1.21 97.78

4.B Manure Management N2O 680.01 1.01 98.79

Key Sources - Emissions by SourceKey Sources - Emissions by Source

Disaggregateda GHG Emissions 2000 Level CumulativeEmission Source in 2000 Assessmentb Total

of LevelGg CO2 % %

1 Enteric Fermentation - Other Cattle CH4 5871.18 8.76 8.762 Energy Industries- Coal CO2 5760.44 8.60 17.36

3 Road Transport - Diesel CO2 4925.62 7.35 24.71

4 Road Transport - Petrol CO2 4610.38 6.88 31.60

5 Energy Industries- Natural Gas CO2 4098.43 6.12 37.71

6 Energy Industries- Oil CO2 3484.39 5.20 42.92

7 Animal Production N2O 2923.30 4.36 47.28

8 Direct Soil Emissions N2O 2817.90 4.21 51.49

9 Enteric Fermentation - Dairy Cattle CH4 2634.03 3.93 55.42

10 Energy Industries- Peat CO2 2324.05 3.47 58.89

Estimation of CH4Estimation of CH4 IPCC Tier 1 methods Three-year averaging + summer-winter averaging of

key livestock populations

N excretion

kg N/year

Dairy Cattle 92.5Other Cattle 50.0Sheep 8.0Pigs 12.0Poultry 0.6

1.50

15.96.50.05.50.1

CH4 emissions (kg/head/yr)

100508

EntericFermentation

ManureManagement

Nitrogen Excretion/ManagementNitrogen Excretion/Management

Animal Waste Management System

(AWMS)

Anaerobic lagoons

Liquid systems

Daily spread

Solid storage & drylot

Pasture range and paddock

Total

498,372,536

Proportion

2

21

14

63

100

Nex

%

105,275,471

-

67,631,943

315,611,652

Nitrogen Excretion Nex(AWMS)

(kg N/yr)

9,853,470

Estimation of N2OEstimation of N2O IPCC methods, accounting for all N inputs Default emission factors (direct and indirect emissions) Default + country-specific values of other variables; Fractions of synthetic fertilizer N and livestock manure

N that volatilizes as NH3 determined directly from NH3 inventory as 0.04 and 0.17, respectively (NOX emission assumed negligible)

Fraction N leached revised to 0.1 as determined from leaching studies and riverine N loading reported to OSPAR

Crop N now included (N-fixing and other) with default values of N fractions and residues/product ratios (Tier 1b)

N-fixing in grasslands not included

Ongoing Research/Improvement Ongoing Research/Improvement

CH4 measurement programme (SF6 technique) for the full range of cattle groups

Detailed characterisation of cattle feed intake Country-specific Tier 2 emission factors for CH4 Detailed farm surveys to determine N excretion rates and

the allocation of organic N by AWMS N2O measurement programme accounting for typical

range of chemical N inputs, typical soil types, rainfall and temperature

Country-specific emission factors for direct emissions of N2O

Implementation of new NH3 inventory with links to indirect emissions of N2O

Future ResearchFuture Research

Major flux measurement campaign for land types Model development to represent gas exchange Up-scaling to determine annual balances Linking to LULUCF research projects and reporting for

LULUCF source/sink categories Assessment of carbon storage capacity of grasslands Introduction of NH3 abatement options