Image: black carbon, a short-lived pollutant (shown in purple), shrouds the globe.
With coastal areas bracing for rising sea levels, new research indicates that cutting emissions of certain pollutants can greatly slow sea level rise this century.Scientists found that reductions in four pollutants that cycle comparatively quickly through the atmosphere could temporarily
forestall the rate of sea level rise by roughly 25 to 50 percent.The researchers focused on emissions of four heat-trapping pollutants: methane, tropospheric ozone, hydrofluorocarbons and black carbon.These gases and particles last anywhere from a week to a decade in the atmosphere and can influence climate more quickly than carbon dioxide, which persists in the atmosphere for centuries.”To avoid potentially dangerous sea level rise, we could cut emissions of short-lived pollutants even if we cannot immediately cut carbon dioxide emissions,” says Aixue Hu of the National Center for Atmospheric Research NCAR in Boulder, Colo., first author of a paper published today in the journal Nature Climate Change.”Society can significantly reduce the threat to coastal cities if it moves quickly on a handful of pollutants.”The research was funded by the National Science Foundation NSF and the U.S. Department of Energy.”Sea level rise and its consequences present enormous challenges to modern society,” says Anjuli Bamzai, program director in NSF’s Division of Atmospheric and Geospace Sciences, which supported the research.”This study looks at projections of global sea level rise, unraveling the effects of mitigating short-lived greenhouse gases such as methane, tropospheric ozone, hydrofluorocarbons and black carbon, as well as long-lived greenhouse gases like carbon dioxide,” says Bamzai.It is still not too late, “by stabilizing carbon dioxide concentrations in the atmosphere and reducing emissions of shorter-lived pollutants, to lower the rate of warming and reduce sea level rise by 30 percent,” says atmospheric scientist Veerabhadran Ramanathan of the Scripps Institution of Oceanography SIO in San Diego, a co-author of the paper. Ramanathan initiated and helped oversee the study.”The large role of the shorter-lived pollutants is encouraging since technologies are available to drastically cut their emissions,” says Ramanathan.The potential effects of rising oceans on populated areas are of great concern, he says. Many of the world’s major cities, such as New York, Miami, Amsterdam, Mumbai, and Tokyo, are located in low-lying areas along coasts.
Dramatic climate change can challenge our survival as a species, so I vote that we should do all we reasonably can while we still can.