Fifty years ago Britain was in the grip of the coldest winter of the 20th century, and the anniversary is prompting comparisons between the present harsh winter weather and the Big Freeze of 1963.
It is clear that 2013, although harsh, will not equal that extreme, at least in terms of duration, because during the cold of half a century ago, it began snowing on Boxing Day 1962, and it was the first week of the following March before the snow began to melt – and in that time, in most of Britain, the snow cover was continuous.
But with six weeks of winter left this year, it is still possible that 2013 may go quite a long way along the spectrum of severity towards the famous 1963 freeze, not least because we seem to be entering a period of severe winters.
There has been a noticeable change in Britain in the last four years. Previously we had experienced a very long run of increasingly warm winters, much of which were considered by scientists to be the product of global climate change. After the last really harsh freeze, of 1978-79, which produced in political terms the famous Winter of Discontent, there was a long period in Britain with very little snow, which had notable effects, such as a near-doubling of the badger population between the mid-1980s and mid-1990s (as the ground was rarely frozen and their earthworm food was available).
But the winter of 2009-10 was quite different, being the snowiest and harshest for 30 years, and the winter of 2010-11 even harsher. The present winter is fitting this pattern, but it is far too soon to predict what the outcome of this season as a whole will be.
Paradoxically, these new harsh winters may be the result of global warming, according to a hypothesis which has been developed by scientists at the Potsdam Institute for Climate Impact Research in Germany, and is being widely considered.
This suggests that the current rapid melting of the Arctic sea ice, which most climate researchers attribute to global warming, is having a major effect on the wind patterns of the northern hemisphere, causing cold, Arctic air to be funnelled over Britain during winter, replacing the mild westerly airstream which normally dominates the UK’s weather.
If this hypothesis is true, it is possible that the exceptional conditions of 1963 may once again return, although no-one can possible say when.