Abstract

Methane emissions from ruminants are New Zealand’s largest source of greenhouse gas emissions. As a signatory to the United Nations Framework Convention on Climate Change and the Kyoto Protocol, New Zealand is committed to producing an accurate inventory of its methane emissions. Official estimates of methane emissions from ruminants have declined since 1990 but because of a failure to take account of changes in agricultural productivity these figures may be misleading. In comparison to Australia, the United Kingdom and the United States of America the methods used in New Zealand to calculate methane emissions comply less well with guidelines published by the Intergovernmental Panel on Climate Change although new methodologies are under development. Estimated errors in methane inventories are large (20-80%) and although some of these errors can be reduced, large biological variation in the processes being quantified places a limit on this.

H, Clarke

Proceedings of the New Zealand Society of Animal Production, Volume 62, Palmerston North, 206-210, 2002