Since at least the 1960s, the shrinkage of the ice cap over the Arctic Ocean has advanced in lockstep with the amount of greenhouse gases humans have sent into the atmosphere, according to a study published this week in Science. Every additional metric ton of carbon dioxide (CO2) puffed into the atmosphere appears to cost the Arctic another 3 square meters of summer sea ice—a simple and direct observational link that has been sitting under scientists’ noses. If current emission trends hold, the study suggests the Arctic will be ice free by 2045—far sooner than some climate models predict. The study suggests that those models are underestimating how warm the Arctic has already become and how fast that melting will proceed. And it gives the public and policymakers a concrete illustration of the consequences of burning fossil fuels. For instance, a U.S. family of four would claim nearly 200 square meters of sea ice, based on U.S. emissions in 2013. Over 3 decades, that family would be responsible for destroying more than an American football field’s worth of ice. |
