Those who wonder why large parts of North America seem to be skipping winter have a new answer in addition to climate change: big city life.
A study, published in the journal Nature Climate Change, found that the heat thrown off by major metropolitan areas on America's east coast caused winter warming across large areas of North America, thousands of miles away from those cities.
Winter warming was detected as far away as the Canadian prairies. In some remote areas, temperature rose by as much as 1 degree C (1.8F) under the influence of big cities, which produced changes in the jet stream and other atmospheric systems, the study found.
Researchers found a similar pattern in Asia, where major population centres resulted in strong warming in Russia, northern Asia, and eastern China.
On the flip side, however, changes in atmospheric conditions had an opposite effect in Europe – lowering autumn temperatures by as much as 1 degree C (1.8F).