Air Pollution May Have Masked Arctic Sea Ice Loss as Far Back as the Mid-20th Century
Humans may have been altering Arctic sea ice longer than previously thought, according to researchers studying the effects of air pollution on sea ice growth in the mid-20th Century. The new results challenge the perception that Arctic sea ice extent was unperturbed by human-caused climate change until the 1970s.
Scientists have observed Arctic sea ice loss since the mid-1970s and some climate model simulations have shown the region was losing sea ice as far back as 1950. In a new study, recently recovered Russian observations show an increase in sea ice from 1950 to 1975 as large as the subsequent decrease in sea ice observed from 1975 to 2005. The new observations of mid-century sea ice expansion led researchers behind the new study to the search for the cause.
The new study supports the idea that air pollution is to blame for the observed Arctic sea ice expansion. Particles of air pollution that come primarily from the burning of fossil fuels may have temporarily hidden the effects of global warming in the third quarter of the 20th Century in the eastern Arctic, the researchers say.