Climate Scientists Urge Ireland to Reject New Methane Accounting Method

Forty-two climate scientists have called on the government of Ireland to reject a proposal that would measure methane emissions from livestock using a method known as Global Warming Potential Star, or GWP*. The scientists said the method, originally developed to assess the warming impact of short-lived greenhouse gases, is being used by the livestock industry and some countries to set targets based on avoiding additional warming instead of cutting emissions.

Background on the Proposal Ireland is a major dairy producer.

The scientists stated that adopting the new method for the country's 2031-2035 carbon budget would permit nine million additional tons of carbon dioxide equivalent emissions, equal to burning about 20 million barrels of oil. New Zealand adopted a similar target in 2025 using the same method, which resulted in a weaker methane reduction goal.

The Intergovernmental Panel on Climate Change and governments that signed the Paris Agreement use a metric called GWP 100, which measures cumulative emissions over a 100-year period relative to carbon dioxide. GWP* instead measures changes in the rate of emissions between two points in time.

The scientists said this allows countries with large existing livestock herds to maintain current emission levels. Methane concentrations in the atmosphere are now about two and a half times higher than before industrialization and account for roughly one-third of global warming.

Paul Behrens, an environmental scientist at the University of Oxford, said other countries are considering similar targets and warned that adopting them would freeze current high emissions rather than reduce them. Drew Shindell, a climate scientist at Duke University, said the method gives an advantage to countries with high current emissions while penalizing developing nations that increase emissions from lower baselines.