Most Britons could be forgiven for thinking a new Ice Age is upon us. Small comfort, then, as we struggle through snowdrifts and cope with burst pipes, that the present cold is a sign the British climate is generally getting milder.
Ironically, most scientists now believe the short sharp shock of severe cold that has struck Europe for three winters running is an indicator that the world is growing warmer. The burning of fossil fuels is building up a blanket of carbon dioxide in the atmospere, creating a "greenhouse" effect.
Britain and Europe have certainly experienced weather this cold before. In the 17th century, the Thames froze solid so often that it became a regular winter sports attraction. The weather then was so severe that it is sometimes referred to as the Little Ice Age. Even in the early 19th century, Britain's climate was still colder than it is today. We still have a cherished picture of Charles Dickens's Christmases — although, in fact, snow at Christmas has been a rarity in southern England for 150 years.
Studies of temperature trends around the world show that it has been warming up since the middle of the 19th century. Most experts agree that this is a result of human activities. By burning coal and oil, we are putting carbon dioxide into the air. This acts like a blanket round the earth, trapping heat that would otherwise escape into space. As long as we keep burning fossil fuel, the trend is likely to continue. So why have we had such severe cold spells in Europe recently? According to researchers at the University of East Anglia, it is all part of the same process. When the climate of the globe changes, it doesn't do so evenly. Britain and Western Europe are just unlucky in being in the path of a particularly significant wind shift.
By comparing the weather in different seasons, during the warmest and coldest years of the 20th century, the researchers have built up a picture of what is going on. Their key new discovery is that although spring, summer and autumn are all warmer, severe cold spells in winter are most likely over the whole of central Europe. So then, short cold spells mean it's generally getting warmer — but the bad news is it could get TOO warm. If the predictions come true — and the present changes are exactly in line with computer forecasts — within the next 40 or 100 years we shall see a change in climate as dramatic as the shift which ended the last Ice Age.
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