A new study completed by Mark Z. Jacobson and presented at the 242nd National Meeting & Exposition of the American Chemical Society (ACS) suggests that reducing soot emissions from diesel engines and other sources could go a long way in slowing the melting of sea ice in the Arctic. Additionally, reducing these emissions presents a faster and cheaper method than many other methods to slow the rate of melting. Calculations made by Jacobson show that controlling soot emissions could reduce warming above the Arctic Circle by almost 3 degrees F in 15 years. According to him, this is almost equivalent to the warming that has occurred there over the last 100 years.
Melting sea ice over the Arctic Circle will not only reduce temperatures directly over the circle, but also be a positive factor for the entire Earth’s climate. Ice reflects heat and sunlight back into space. If the ice melts, the darker water underneath will absorb heat and increase the rate of warming, much like wearing a black shirt.
“No other measure could have such an immediate effect,” said Jacobson, who is with Stanford University. “Soot emissions are second only to carbon dioxide (CO2) in promoting global warming, but its effects have been underestimated in previous climate models. Consequently, soot’s effect on climate change has not been adequately addressed in national and international global warming legislation. Soot emissions account for about 17 percent of global warming, more than greenhouse gases like methane. Soot’s contribution, however, could be reduced by 90 percent in five to 10 years with aggressive national and international policies.”
Soot is emitted from the combustion of fossil fuels and biofuels. Also known as “black carbon”, soot consists of nearly invisible particles released in the form of smoke. Major sources of soot include diesel cars, buses, trucks, ships, aircrafts, agricultural machines, construction equipment and wood/animal dung fires commonly used for cooking and heating in developing nations.
The technology to reduce soot emissions is already available. Diesel particulate filers can be utilized on car and truck exhausts. Many government and non-government agencies are also trying to incorporate low-soot cookstoves into the lives of people in developing countries. The use of electric and hydrogen vehicles will also reduce emissions from diesel-burning cars and trucks.
The effect of reducing soot emissions can happen rapidly. This is because soot disappears within a few weeks, unlike carbon dioxide which remains in the atmosphere for years. Therefore, long-term reservoirs that have continuous warming effects do not exist for soot emissions.
To learn more about Mark Jacobson and his work on this subject, click here.