Rising Sea Levels Could Be Slowed By Dealing With Four Short-Term Pollutants; CO2 In The Long Run

Rising sea levels are expected to begin affecting many coastal cities in the decades to come, and researchers have been scrambling for a way to curb the impending flooding. An encouraging new study now states that curbing four key pollutants can effectively slow the rate of sea level rising by 25 to 50 percent.

The four pollutants - methane, tropospheric ozone, hydrofluorocarbons, and black carbon - are short-lived and cycle through the atmosphere far quicker than carbon dioxide. 

"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 study author Aixue Hu from the National Center for Atmospheric Research (NCAR). "This new research shows that society can significantly reduce the threat to coastal cities if it moves quickly on a handful of pollutants."

A 2007 Intergovernmental Panel on Climate Change report stated that sea levels could rise 7 to 23 inches this century - an estimate many find too conservative. Contributors to this alarming rate include melting ice caps, which in turn are caused by rising global temperatures. Carbon dioxide, which can stay in the atmosphere for hundreds of years, has normally been singled out as the most damning greenhouse gas, but as the researchers point out, attacking shorter-term pollutants could buy us more time to deal with the larger issues. 

"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," says study leader Veerabhadran Ramanathan from Scripps University. "The large role of the shorter-lived pollutants is encouraging since technologies are available to drastically cut their emissions."

The study's authors believe that with proper implementation and use of technology currently available, countries can cut emissions of these four harmful pollutants by 30 to 60 percent over the next few decades. 

Still, while these moves are definitely a step in the right direction, and do buy our society more time, it's important to keep our eyes on the prize, the scientists state. 

"It must be remembered that carbon dioxide is still the most important factor in sea level rise over the long term," says NCAR scientist Warren Washington said. 

The study, carried out with members from NCAR, Scripps, and Climate Central, can be read in the journal Nature Climate Change.