New Analysis Says GWP* May Let Countries Understate Livestock Methane Emissions
A Greenpeace‑commissioned study warns that the GWP* accounting method could let nations report lower methane emissions from livestock.
Background to the upcoming climate summit
Climate negotiators will travel to Turkey next month for the United Nations annual climate summit, known as the Conference of the Parties (COP). The trip follows a recent U.N. report that warned the world’s chance of limiting warming to safe levels is vanishing.
Why methane matters
Methane is a short‑lived greenhouse gas that is about 80 times more potent than carbon dioxide over a 20‑year horizon. Because of its strong but brief warming effect, cutting methane emissions is seen as a fast way to reduce overall warming.
Controversy over measuring livestock methane
Scientists say GWP100 does not capture methane’s rapid warming power because methane’s impact peaks quickly and then declines after about 12 years. About a decade ago, researchers at the University of Oxford created GWP*, which translates emission rates of short‑lived gases like methane into equivalent pulses of carbon dioxide.
GWP* assumes that steady methane emissions do not add extra warming, since the gas breaks down relatively fast and its sources—such as cow belches—originate from vegetation that previously removed carbon dioxide from the atmosphere.
Greenpeace’s response
Sophie Nodzenski, a campaigner with Greenpeace, said, Proponents of GWP* will tell you methane is part of the natural carbon cycle, we just need to keep it stable. We argue that methane levels are already too high. Methane is the climate emergency brake. It disappears so quickly from the atmosphere and is so warming—if we acted on methane right now, we could see results within the next 15 years.
Implications for the COP talks
The analysis suggests that the way methane is accounted for could affect how countries report progress toward climate goals at the upcoming COP summit.
