The past several days have seen much of the United States gripped by freezing temperatures as the northerly jet stream pushed Arctic air south across North America. This has provided fuel for global-warming skeptics, even as scientists debate whether the extreme cold might in fact be a consequence of a warming climate. Nature takes a look at the underlying science…One theory is that a warmer Arctic will reduce the temperature differences between the Arctic and warmer latitudes, leading to a weaker jet stream that would be more likely to wander off course from time to time. "Of course, we can’t say that this particular pattern is due to warming, but it’s very consistent with what we expect to see happen," says Jennifer Francis, an atmospheric scientist at Rutgers University in New Brunswick, New Jersey, who published a study on this effect in Geophysical Research Letters in 20121.
/ / / US cold snap fuels climate debate