US Cold Snap Fuels Climate Debate

A sudden drop in temperatures across the United States has ignited debate about the influence of climate change and polar melt over the stability of one of the world’s two jet streams. “The polar jet stream is a natural product of Earth’s rotation and climate system, created as warm air from the south merges with cold Arctic air,” writes Jeff Tollefson for Nature. “Most of the time it is fairly stable, circling the planet and effectively containing the cold air within the Arctic.” Scientists won’t characterize a single weather event as connected to global warming. One theory has suggested that warming temperatures and arctic melting could weaken the jet stream, prompting it to meander. Another researcher analyzed more than 30 years of data and found no connection between melting polar ice and jet-stream meandering. There’s no doubt that changes in in the jet stream path have an immediate influence over temperatures and economic productivity. – YaleGlobal