Finally, there's some good news on reducing climate change, which is great news as far as I'm concerned. I'm a climate skeptic. It's not that I'm skeptical about the existence of climate change, but I'm extremely skeptical about mankind's collective willingness to do anything about it in a timely manner.
Late last year, the Global Carbon Project issued a report showing global emissions of carbon dioxide rose to record levels in 2011 and were on track to rise even higher in 2012. Carbon dioxide is produced most often by the burning of coal, the largest global source of energy used to generate electricity.
Carbon dioxide in the atmosphere causes glaciers and ice sheets to melt and warming oceans to expand. But a new study by the National Center for Atmospheric Research, the Scripps Institution for Oceanography, and Climate Central shows that by limiting four other pollutants that might be easier to control, scientists can make significant progress toward stemming rising sea levels.
For a host of reasons, international policy makers have been unable to agree on how to reduce emissions of carbon dioxide or CO2, the main greenhouse gas created by human activity. The new study shows that by limiting emissions of four substances -- methane, soot, refrigerants, and gases that lead to the formation of ground-level ozone -- progress could still be made, possibly even more quickly.
These four gases and particles remain in the atmosphere anywhere from a week to a decade. CO2, on the other hand persists in the atmosphere for more than a century. So limiting emissions of the group of four pollutants can reverse rising sea levels more quickly than by limiting CO2.
The research team found that reductions in those four pollutants would cycle comparatively quickly through the atmosphere. As a result, their limitation could slow the annual rate of sea level rise by roughly 25 to 50 percent.
This is major news. Many Americans still doubt the existence of climate change or manmade climate change. But after Superstorm Sandy last year and Hurricane Katrina in 2005, hardly anyone can argue that low-lying cities have no reason to fear rising sea levels. I'm not sure how those who would deny anthropogenic climate change explain how sea levels are rising, but somehow they do.
In any event, the report's authors note: "The potential impact of rising oceans on populated areas is one of the most concerning effects of climate change. Many of the world's major cities, such as New York, Miami, Amsterdam, Mumbai and Tokyo, are located in low-lying areas by the water."
So why would it be easier to regulate emissions of soot and refrigerants than it has been to regulate CO2 emissions? One reason: There would be fewer and smaller corporate interests lobbying against their regulation. Soot or black carbon is emitted into the atmosphere when combustion of biomass or fossil fuels is incomplete. It often occurs when burning biomass or crop residue.
Cooking -- with wood, crop residues and dung -- is also a major source of soot. One can imagine that a government could more easily regulate cooking with dung or crop residues than it could fight the immensely powerful coal lobby.
The authors note carbon dioxide emissions must still be cut over time. But this study shows more immediate, substantial gains from limiting the use of shorter-lived pollutants. Cutting emissions of those gases would give coastal communities more time to prepare for rising sea levels.
That is a gift of time few saw coming. It is one that policymakers should try to use wisely and swiftly.
(Bonnie Erbe, the host of PBS' "To the Contrary," writes this column for Scripps Howard News Service.)