An Oregon State University researcher has found melting Arctic snow and sea ice are contributing more to global warming than international climate models estimate.
Karen Shell is an assistant professor of oceanic and atmospheric sciences at OSU. She took part in a study that compared changes in snow and ice in the Northern Hemisphere from 1979 to 2008 with 18 different climate models.
The researchers found snow and ice were absorbing twice as much sunlight as state-of-the-art climate models estimate.
Shell says the more sunlight the melting snow and ice absorb, the less cooling effect they will have on the Earth as a whole. That’s what scientists call “albedo feedback.”
Karen Shell: “The current models are underestimating this albedo feedback, and so if that’s the only thing that changes that means they would be underestimating global warming in response to increased carbon dioxide.”
Shell says new climate models due out this year will have more accurate estimates of the global warming effect of melting snow and ice, which will be one of many factors in new climate change predictions.