Cutting Soot Emissions Best Hope for Arctic Sea Ice, Study Shows
31.07.2010 - Atmosphere & Space, Ice & Snow, Arctic
In a new study published in the Journal of Geophysical Research–Atmospheres, Mark Jacobson, director of Stanford University’s Atmosphere/ Energy Program, found that the influence of black carbon (soot) has been widely underestimated regarding its contribution to global warming. Controlling soot, Jacobson says, may be the only option for saving the Arctic sea ice from melting.
Over the past 20 years, Jacobson developed an intricate computer model of global climate, air pollution and weather to include atmospheric processes not incorporated in previous models. He examined the effects of soot (black and brown particles that absorb solar radiation) from fossil fuels and solid biofuels on heating clouds, snow and ice. By designing the first global model to use mathematical equations to describe the physical and chemical interactions of soot particles in cloud droplets in the atmosphere, Jacobson was able to include details such as light bouncing around inside clouds and within cloud drops, which he said are critical for understanding the full effect of black carbon on heating the atmosphere. Jacobson argues that leaving out this scale of detail in other models has led many scientists and policymakers to undervalue the role of black carbon as a warming agent.
The effect of black carbon has the most profound effects in the Arctic, where sunlight can be absorbed by the black carbon particles both on its way through the atmosphere and in the snow and ice as light reflects back toward space. Black carbon particles on snow or ice darkens the surface and enhances melting.
According to Jacobson, eliminating soot could reduce warming above parts of the Arctic Circle by up to 1.7°C in the next 15 years.
