Over it’s historical record, in January, Northern Hemisphere snow cover averages 47 million square kilometers (18.1 million square miles), and in February it averages 46 million square kilometers (17.8 square miles)—approximately 45 to 46 percent of the land area in the region. While sea ice extent was below average for January 2011, this month had the sixth-largest snow cover extent since the record started in 1966, at 49 million square kilometers (18.9 million square miles). Snow was unusually widespread over the mid-western and eastern United States, eastern Europe, and western China. Snow cover in February remained above average at 47.4 million square kilometers (18.3 million square miles), with more snow than usual in the western and central U.S., eastern Europe, Tibet and northeastern China.

Reduced sea ice extent and extensive snow cover are not contradictory, and are both linked to a strong negative phase of the Arctic Oscillation (see our January 5, 2011 post). A strongly negative AO favors outbreaks of cold Arctic air over northern Europe and the U.S., as many people experienced first-hand these last two winters. Whether this is a trend, or in any way linked to ongoing climate warming in the Arctic, remains to be seen.

Then, in 1979, Mrs Margaret Thatcher (now Lady Thatcher) became Prime Minister of the UK, and she elevated the hypothesis to the status of a major international policy issue.

Mrs. Thatcher could not have promoted the global warming issue without the support of her UK political party. And they were willing to give it. Following the General Election of 1979, most of the incoming Cabinet had been members of the government which lost office in 1974. They blamed the National Union of Mineworkers (NUM) for their 1974 defeat. They, therefore, desired an excuse for reducing the UK coal industry and, thus, the NUM’s power. Coal-fired power stations emit CO2 but nuclear power stations don’t. Global warming provided an excuse for reducing the UK’s dependence on coal by replacing it with nuclear power.