Tuesday’s formal announcement of an US-EU-led pledge to reduce global methane emissions by 30% by 2030 could well prove to be one of the most significant outcomes of COP26.
When methane is discussed in Ireland, it is exclusively understood to be associated with agriculture.
But in an international context, while ruminant livestock and the production of manure account for about a third of total methane emissions (compared to almost 100% in Ireland), landfills and waste water contribute about 20%; oil, gas and coal mining amount to about 26%; and rice production generates another 10%.
The tenure of the global pledge very much stresses the role of non-livestock-produced methane. It would be a big mistake, therefore, to extrapolate the global perspective on methane to an Irish context.
And the Taoiseach Micheál Martin was very careful to emphasise that, in signing up to the pledge along with 80 or so other countries, he was supporting a global commitment and this could not be interpreted as applying to Ireland.
Non-livestock methane sources
Indeed the solutions that are proposed to generate the 30% reduction in methane by 2030 prioritise the non-livestock sources. And importantly, none of the measures that are put forward to reduce methane in the ruminant livestock sector involve a policy-generated reduction in animal numbers.
This is not surprising, as while reductions in methane in the non-livestock sectors will incur costs, they will not threaten the very existence of these sectors. In contrast, if animal numbers were to be deliberately reduced to curb methane, this would threaten the survival of these enterprises on many farms.
While reductions in methane in the non-livestock sectors will incur costs, they will not threaten the very existence of these sectors
The measures that are proposed for livestock concern improved manure management, anaerobic digestion, feed additives, composting and genetic selection for low-methane production. Most of these factors are, of course, included in the Teagasc Marginal Abatement Cost Curve (MACC).
The combination of these measures would be at most be likely to achieve a 10% reduction in the production of biogenic methane by 2030. This outcome would of course be consistent with what’s recommended by AgClimatise and Vision2030.
When it comes to action on the pledge, the international focus to achieve the greater bulk of the 30% cut will be on fixing leaks in pipes, landfills and old coal mines. Irish policymakers would do well to bear this in mind.
Professor Gerry Boyle is the former Director of Teagasc and former member of the Climate Change Advisory Council, and is at COP26 in Glasgow, Scotland.