Arctic ice provides more than just homes for fish and mammals – it also slows global warming.

Dwindling sea ice in the Arctic Ocean is creating large areas of relatively dark ocean surface that reduce the albedo, or reflectivity, of the polar region. More open water causes the Earth to absorb more of the sun’s solar energy rather than reflect it back into the atmosphere. A new study by researchers at Scripps Institution of Oceanography, UC San Diego, has found that the impact this phenomenon is having on global warming has likely been substantially underestimated.

‘It’s fairly intuitive to expect that replacing white, reflective sea ice with a dark ocean surface would increase the amount of solar heating,” Kristina Pistone, a graduate student at Scripps who participated in the research, said in a statement.

However, the study, published Monday in the Proceedings of the National Academy of Sciences, used direct satellite measurements for the first time rather than computer models to determine that the magnitude of surface darkening has been two to three times as large as found in previous studies.

‘Scientists have talked about Arctic melting and albedo decrease for nearly 50 years,” Veerabhadran Ramanathan, a distinguished professor of climate and atmospheric sciences, […]