NASA first began using satellites to monitor Arctic sea ice in 1979, putting attention on a key player in the planet’s health.
Since that time, the agency has tracked the decline of the ice pack as it has continued to shrink. As of March, the ice pack was 620,000 square miles smaller than it was in 1979.
While the cause of global climate change continues to be a hot-button political topic in the United States, a researcher in UT’s College of Engineering may have pinpointed the reason for the retreat of sea ice.
Joshua Fu, a professor of civil and environmental engineering, has been instrumental in the study of black carbon.
“There’s been a tremendous amount of Arctic ice melt, whereas the melting in Antarctica hasn’t been as severe,” said Fu. “We set out to look at the reasons why that might be, and black carbon emerged early on as a key substance.”
Black carbon is a result of the incomplete burning of fossil fuels, which results in a concentration of particulate matter that’s higher than what is typically found in other forms of air pollution. Because of that extra matter, black carbon has the tendency to settle back to the ground.
As anyone who has owned a dark car can attest, the outside air temperature doesn’t have to be all that warm to make the inside of the vehicle uncomfortably toasty.
In much the same way, when black carbon follows the global air patterns north and settles on the ice, it greatly increases its temperature compared to the outside air. This warming, in turn, melts the ice at a quicker rate.
“The black carbon melts the ice faster, which decreases the amount of ice in the Arctic, which means there’s less ice to reflect the sun’s rays, which warms the region and melts the ice even more rapidly,” said Fu. “It’s a double hit on the Arctic.”
Fu was able to build models that track black carbon pollution back to its source by monitoring nitrogen oxides, whose rates are closely tied to black carbon. That breakthrough was so astounding that NASA even reached out to him for feedback and input.
What he found was that most of the black carbon came from just three regions: Siberia, the Niger Delta, and the Middle East, with 26 percent of the substance coming from Russia alone.
The thing all three regions have in common? They are all major petroleum producing regions where, incredibly, mass quantities of natural gas are burned off as a waste product.
The impact from the United States was much smaller, though the rapid growth of fracking sites, which often burn gas, has seen the country climb from thirteenth to fifth in the overall rankings of black carbon producers.
The next step for Fu is to expand research efforts and improve black carbon tracking methodology, something made easier by the burgeoning cooperation between NASA, the U.S. Department of Energy, Russia, and researchers.
“If we can come up with a better way to track black carbon itself independent of nitrogen oxides, we can make a more pinpointed effort to controlling them and finding ways of reducing them,” said Fu.
He added that he’s begun working with the first doctoral student he had, Louis Diaz, who is now a professor in Chile. Together, they are studying ways of monitoring glacial decline in the Andes Mountains as well as Antarctica.
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CONTACT:
David Goddard (865-974-0683, david.goddard@utk.edu)