Action could help avert climate tipping points
FRISCO — Leading scientists say the U.S. must do more to cut methane emissions from fossil fuel exploitation and other sectors to try and avoid reaching climate tipping points that could have disastrous implications.
Methane is a much more potent heat-trapping gas than carbon dioxide, but it only stays in the atmosphere for about 12 years, which means that big cuts could have a tangible short-term benefit in the race to cap global warming.
The scientists expressed their concerns in a July 29 letter to Energy Secretary Ernest Moniz, explaining that government agencies should use short-term calculations when they assess the effects of methane gas and the benefits of cutting emissions.
An excerpt from the letter:
“Specifically, we ask that that the Administration’s methane mitigation effort include steps that will slow near-term climate change while also contributing to capping long-term warming. Because use of the 100-year Global Warming Potential (GWP) spreads out the strong near-term warming influence of methane over a period roughly ten times its atmospheric lifetime, the present reliance on GWP-100 in identifying optimal actions obscures the potential for cutting emissions of methane (and other short-lived warming agents) to slow the pace of climate change. To facilitate better development of emissions-reduction policies that will contribute to limiting both near- and long-term climate change, we recommend that the Administration and agencies adopt and require the use of both the 20-year and the 100-year GWPs for methane.”
“Reducing the oil and gas industry’s massive methane pollution could help provide the breathing room we need to avoid disastrous climate tipping points,” said Shaye Wolf, climate science director at the Center for Biological Diversity, who signed the letter. “The Obama administration has to start using accurate estimates of methane’s short-term climate effects. But our government also has to take swift action against this dangerously potent greenhouse gas.”
While the Department of Energy is examining opportunities for reducing methane from the natural gas sector, officials have focused primarily on voluntary measures. But experts say stronger reductions are needed under the Clean Air Act.
The Obama administration has acknowledged the importance of methane as part of the president’s Climate Action Plan, but federal agencies continue to use only 100-year methane global warming potentials and outdated values from the Intergovernmental Panel on Climate Change’s Second Assessment Report, which was released nearly 20 years ago.
“Methane reductions are also feasible technologically today and can, in many cases, be achieved in a cost-neutral or even cost-positive way, and this opportunity for action must not be under-estimated,” the scientists wrote.