Longer and colder winters because of global warming


We are in April and finally a hot sunny day after a long winter. However, some Northern Hemisphere locations still have cold temperatures. Some people wonder "why the winter was so long if we talk about global warming?". Actually global warming may be the reason for longer and colder winters.
Global warming produces more glacier retreat. Although some people wonder whether glaciers retreat faster or slower than predicted, the fact is that they are retreating, as explained in a previous article. Although the Arctic has already reached its maximum yearly extent, such extension is the 6th lowest according to the satellite records.
Image 1. Extreme and unusual snowfall in UK
Source: The Telegraph

How does less glacier means colder winter?
An article just published at the "Proceedings of the Academia Science of the United States" shows that Less Arctic sea ice alters atmospheric circulation leading to more snow and ice.

Without a substantial ice cover, Arctic wind is less constrained. Thus, the jet stream of cool air that regulates weather then dips farther and farther south, bringing cold air from the Arctic closer to the Equator. Hence, much colder weather extents into the spring much longer

Besides, Arctic ice locks up water molecules. Once the ice melts, the water molecules change into liquid state, which in turn will evaporate increasing the air moisture. Such moisture will eventually return to earth as precipitation; heavier precipitation than with less moisture. The precipitation may be either rainfall or snowfall. The point is, since there is more precipitation source (air moisture), it is reasonable to expect heavier precipitation.

References and Additional Reading

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