PITTSBURGH — Last week, a landmark climate report from the United Nations gave the sobering consensus of decades of international climate change research: “It is unequivocal that human influence has warmed the atmosphere, ocean and land,” causing “widespread and rapid changes” in the air, seas, once-frozen places and plant and animal life that have touched every region on Earth.
Worse changes could be limited by deep, swift and lasting reductions in greenhouse gas emissions, but it could take 20 or 30 years for global temperatures to stabilize after that, the report said. Some changes to the oceans, ice sheets and sea level will be irreversible for hundreds or thousands of years.
One new focus of the report from the Intergovernmental Panel on Climate Change is potent greenhouses gases that last decades or less in the atmosphere — especially methane — because cutting those is a leading strategy for slowing warming relatively quickly. Amy Townsend-Small, an associate professor of environmental science at the University of Cincinnati, has been studying the second-most abundant greenhouse gas emitted through human activities for over a decade.
This interview has been edited for space and clarity.
Q. The new Intergovernmental Panel on Climate Change assessment is clear carbon dioxide is the primary driver of human-caused climate change and curbing carbon dioxide will be the primary solution. But it also says “strong, rapid and sustained reductions” in methane emissions are important. Why is that?