Cold winters in Europe caused by less summer sea ice

The first reaction by the public when a cold snap hits is to criticise scientists who talk of global warming, and how ridiculous it all seems. In fact, science has predicted that cold weather, especially in Eastern Europe during winter, is likely to be intensified by the lack of summer sea ice over the Arctic.

Scientists at the Alfred Wegener Institute for Polar and Marine Research have shown yet again, that global warming is a complex process and that warming in one region may lead to cooling in others, despite an overall warming trend.

The loss of sea ice in the Arctic leads to two important effects: the retreat of lighter coloured ice in favour of darker ocean, which in turn causes warming of the ocean. Secondly, the lid effect of the ice cap is removed, causing the warmer ocean to heat the atmosphere. This warming effect has been clearly measured and causes a rising air mass over the arctic, which in turn influences normal circulations in the region. The air pressure difference between the Arctic and the mid-latitudes can therefore be reduced, lessening Atlantic westerly’s and letting the arctic air push south into Europe.

Just a few weeks ago, this pattern did not seem to be occurring like the last few winters; instead the warmer westerly pattern was dominating, but now this has changed and yet again Europe is experiencing a cold winter. Deaths related to the cold-wave have now reached the hundreds, with temperatures dipping below -30C in parts of Eastern Europe.

It is never easy to make medium term predictions of climate. The further we go into the future, the easier it is to say climate change will be having an impact. Yet freak winter weather like this has backed up the scientists yet again. This goes along with the record warm years we have seen in the last decade and the rapid decline of world glaciers and the Arctic ice sheets.