The stubborn worry about climate change that just won’t go away

New research suggests that warm spells at the top of the world can, surprisingly, cause unusually cold weather in parts of North America — and that could be hurting plants, damaging agriculture and even affecting the amount of carbon dioxide that goes into our atmosphere. Plus, it further reinforces a controversial but persistent theory suggesting that the fast-warming of the Arctic could be causing weather extremes in the heavily populated mid-latitudes as well. The new study, just out Monday in the journal Nature Geoscience by a team of researchers from South Korea, China and the United States, finds that warmer-than-usual springtime temperatures in the Arctic Ocean are followed by colder-than-usual temperatures across much of North America, as well as a reduction in precipitation in some parts of the southern United States. And these conditions are also associated with a reduction in plant growth and development, in some cases even leading to reduced crop yields.