Harvard Researchers Provide Policymakers a Clearer Picture on Methane Emissions

CARBON DIOXIDE IS THE USUAL VILLAIN in the climate change story. Emitted largely through the use of fossil fuels, it not only warms the planet now, but will continue to do so for more than a century while it remains in the atmosphere.

Less well known is the role that another greenhouse gas—methane—plays. About one third of global methane emissions occur naturally, mostly from wetlands. But two-thirds are caused by human activity, including from oil and gas operations, coal mining, landfills, plus livestock and rice paddies. And because of its chemical composition, methane has a much higher global-warming potential than carbon dioxide does—up to 80 times as much—and is responsible for about a third of current global warming. But crucially, methane lingers in the atmosphere for much less time than carbon dioxide does—only about 10–20 years.

“What that means is that methane is responsible more for near-term climate change, but it also means that acting on methane can give us a short-term climate response,” says Daniel Jacob, the Vasco McCoy Family Professor of Atmospheric Chemistry and Environmental Engineering at Harvard University. “So, if we are trying to address climate change over the next decade or two, methane is a very powerful lever.”

Jacob and Robert Stavins, the A.J. Meyer Professor of Energy and Economic Development at Harvard Kennedy School and director of the Harvard Environmental Economics Program and the Harvard Project on Climate Agreements, are combining their respective natural sciences and public policy expertise on a project designed to help policymakers use that lever. For countries currently working to address climate change through a variety of international agreements, the Harvard team’s efforts will help policymakers more precisely determine their existing emissions and, from there, their proposed cuts....