New global warming advice
Cut methane, soot for short-term relief
WASHINGTON — An international team of scientists says it has figured out how to slow global warming in the short run and prevent millions of deaths from dirty air: Stop focusing so much on carbon dioxide.
They say the key is to reduce emissions of two powerful and fast-acting causes of global warming — methane and soot.
Carbon dioxide is the chief greenhouse gas and the one world leaders have spent the most time talking about controlling. Scientists say carbon dioxide from fossil fuels like coal and oil is a bigger overall cause of global warming, but reducing methane and soot offers quicker fixes.
Soot also is a big health problem, so dramatically cutting it with existing technology would save between 700,000 and 4.7 million lives each year, according to the team’s research published online Thursday in the journal Science.
Two dozen scientists from around the world ran computer models of 400 different existing pollution control measures and came up with 14 methods that attack methane and soot.
All 14 methods — capturing methane from landfills and coal mines, cleaning up cook stoves and diesel engines, and changing agriculture techniques for rice paddies and manure collection — are being used efficiently in many places, but aren’t universally adopted, said the study’s lead author, Drew Shindell of NASA.
If adopted more widely, the scientists calculate that would reduce projected global warming by 0.9 degrees Fahrenheit by the year 2050. Without the measures, global average temperature is projected to rise nearly 2.2 degrees Fahrenheit in the next four decades.
But controlling methane and soot, the increase is projected to be only 1.3 degrees. It also would increase annual yield of key crops worldwide by almost 150 million tons.
Methane comes from landfills, farms, drilling for natural gas, and coal mining. Soot is a byproduct of burning.