A change in the world's so-called jet stream may be causing our incredibly bitter winter, with a little help from climate change. Professor Jennifer Francis of Rutgers University gave a talk in Chicago yesterday saying that the jet stream—a high-speed air current in northern latitudes—has been weakening as the Arctic gets warmer, the BBC reports. Normally the temperature clash between cold Arctic air and warmer southern air fuels the jet stream. But with less clash, the jet stream meanders and fails to push cold weather patterns away.
Francis said the changing jet stream has other effects too, like driving cold weather south (see Atlanta's "catastrophic" storm) and warm weather north (like the unusually warm winter in Alaska and parts of Scandinavia). But she admits it's too early to fully blame climate change, and even the "meandering jet stream" notion remains controversial, AFP reports. "There is evidence for and against it," said Colorado scientist Mark Serreze. However, he said that warmer Arctic temperatures are indeed melting ice caps and releasing warm air into the atmosphere. (Read more climate change stories.)