Researchers at the University of California, Irvine, believe that while the threat of greenhouse emissions exists, soot-infused or dirty snow also contributes to global warming.
If Charlie Zender, an Associate Professor of Earth System Science at the UCI and co-author of the study, is to be believed, dirty snow contributes to a third or more of Arctic warming.
Zender claims that snow becomes dirty when soot from tailpipes, smoke stacks and forest fires enters the atmosphere and falls to the ground. Soot-infused snow is darker than natural snow. Dark surfaces absorb sunlight and cause warming, while bright surfaces reflect heat back into space and cause cooling.
The study, which appears in this week's issue of the Journal of Geophysical Research, further goes on to say that dirty snow has had a significant impact on climate warming since the Industrial Revolution.
In the past 200 years, the Earth has warmed about .8 degree Celsius. Dirty snow caused the Earth's temperature to rise .1 to .15 degree, or up to 19 percent of the total warming, Zender and his colleagues claimed.
As far the Arctic region is concerned, the researchers say that In the past two centuries, it has warmed about 1.6 degrees, and added that dirty snow caused .5 to 1.5 degrees of warming, or up to 94 percent of the observed change.
Other human influences on Arctic climate change are particles in the atmosphere, including soot; clouds; and land use. According to the researchers, humans create the majority of airborne soot through industry and fuel combustion, while forest and open-field fires account for the rest.
Previous studies have analyzed dirty snow's effect on climate, but this is the first to take into account realistic emissions from forest fires in the Northern Hemisphere and how warming affects the thickness of the snow pack.
Dirty snow is also prevalent in East Asia, Northern Europe and Northeastern United States, and Zender believes policymakers could use these research results to develop regulations to mitigate global warming.