Estimates of enteric methane emissions from cattle in Canada using the IPCC Tier-2 methodology

• Published in: Canadian Journal of Animal Science
• Main Authors: Ominski, K. H., Boadi, D. A., Wittenberg, K. M., Fulawka, D. L., Basarab, J. A.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Canadian Science Publishing 2007
• Subjects: Newfoundland
• Online Access: http://dx.doi.org/10.4141/cjas06034; http://www.nrcresearchpress.com/doi/pdf/10.4141/CJAS06034

The objective of this study was to estimate enteric methane (CH 4 ) emissions of the Canadian cattle population using the International Panel on Climate Change (IPCC) Tier-2 methodology. Estimates were then compared with IPCC Tier-1 methodology and data from Canadian research studies (CRS). Animal inventory data for the Canadian beef and dairy cattle herd was obtained from Statistics Canada. Information on cattle performance and feeding practices were obtained from provincial cattle specialists via a survey, as well as various published reports. Methane emissions from dairy and beef cattle in Canada for 2001 were 173 030 t yr -1 or 3.6 Mt CO 2 eq. and 763 852 t yr -1 or 16.0 Mt CO 2 eq., respectively, using Tier-2 methodology. Emissions for dairy cattle ranged from 708 t yr -1 in Newfoundland to 62 184 t yr -1 in Ontario. Emissions for beef cattle ranged from 191 t yr -1 in Newfoundland to 356 345 t yr -1 in Alberta. The national emission factors (kg CH 4 yr -1 ) using IPCC Tier-2 were 73, 126, 90, 94, 40, 75, 63 and 56 for dairy heifers, dairy cows, beef cows, bulls, calves < 1yr, beef heifer replacements, heifers > 1 yr, and steers > 1yr, respectively. Emission factors (kg CH 4 yr -1 ) for the above classes of cattle using IPCC Tier-1 were 56, 118, 72, 75, 47, 56, 47 and 47, respectively. The values were 15.1% higher to 25.3% lower than those obtained using IPCC Tier-2 methodology. When IPCC Tier-2 emission factors were compared with CRS, they were 12.3% lower to 32.6% higher than those obtained using the Tier-2 methodology. In conclusion, national estimates of enteric emissions from the Canadian cattle industry using Tier-1 and Tier-2 methodologies, as well as CRS, differ depending on the methodology used. Tier-2 methodology does allow for the inclusion of information other than population data, including feeding strategies, as well as duration of time in a given production environment. Additional research is required to establish the extent to which feed energy is converted to methane for those ...