Guardian Have All Bases Covered
By Paul Homewood
Just in case we get a cold winter this year, the Guardian thought it advisable to warn us that this would no doubt be because of global warming.
The record loss of Arctic sea ice this summer may mean a cold winter for the UK and northern Europe. The region has been prone to bad winters after summers with very low sea ice, such as 2011 and 2007, said Jennifer Francis, a researcher at Rutgers University
Well yes, Jennifer. It has also been prone to mild winters recently. It was also prone to cold winters when the Arctic had more summer ice, and also mild winters in other years at the time. It is actually called “weather”.
Jennifer helpfully explains
"The jet stream is clearly weaker," said Francis. That means weather systems, be it rain or dry conditions, are slow to move on and last longer. Ultimately this can result in "blocking" events, such as the conditions that produced the terrible heatwave in western Russia during the summer of 2010, she said.
What Jennifer is referring to is what meteorologists call a “meridional jet stream”. Meteorologist Jeff Haby explains this phenomenon in layman terms below.
Are you keeping up so far, Jennifer? Good. Let’s go onto stage two then.
Hubert Lamb is one of the best known climate scientists of all time, and founded the Climate Research Unit at the UEA. In his book, “Climate: Past, Present & Future”, he talks about the climate during the 1960’s and early 70’s when the Arctic was getting colder and sea ice expanding. He identifies one of the effects of this Arctic shift as
“changes over middle latitudes, where the most significant feature has been the very awkward type of variability from year to year, associated with the behaviour of blocking systems and meridional circulation patterns.” which led to “the extremes of cold and warmth, drought and flood associated with the occurrences of blocking in middle latitudes.”
Scientists at the time even identified the mechanism involved
“The slight drop in temperature produces large numbers of pressure centres in the upper atmosphere. These break up the smooth flow of westerly winds over temperate areas.The stagnant air produced in this way causes an increase in extremes of local weather such as droughts, floods, extended dry spells, long freezes, delayed monsoons and even local temperature increases.”
Of course Lamb and his colleagues might have been wrong. But, if so, perhaps Jennifer might like to explain the UK’s Big Freeze of 1963, which lasted three months and was caused, according to the Met Office, by a high pressure system stuck for most of the winter to the north-east?
Meanwhile, whether this winter is mild, cold, wet, dry, snowy, windy, or just plain normal, the hacks at the Guardian will have the answer. Global Warming!