The supposed ‘consensus’ on man-made global warming is facing an inconvenient challenge after the release of new temperature data showing the planet has not warmed for the past 15 years.
The figures suggest that we could even be heading for a mini ice age to rival the 70-year temperature drop that saw frost fairs held on the Thames in the 17th Century.
Based on readings from more than 30,000 measuring stations, the data was issued last week without fanfare by the Met Office and the University of East Anglia Climatic Research Unit. It confirms that the rising trend in world temperatures ended in 1997.
A painting, dated 1684, by Abraham Hondius depicts one of many frost fairs on the River Thames during the mini ice age
Meanwhile, leading climate scientists yesterday told The Mail on Sunday that, after emitting unusually high levels of energy throughout the 20th Century, the sun is now heading towards a ‘grand minimum’ in its output, threatening cold summers, bitter winters and a shortening of the season available for growing food.
Solar output goes through 11-year cycles, with high numbers of sunspots seen at their peak.
We are now at what should be the peak of what scientists call ‘Cycle 24’ — which is why last week’s solar storm resulted in sightings of the aurora borealis further south than usual. But sunspot numbers are running at less than half those seen during cycle peaks in the 20th Century.
Analysis by experts at NASA and the University of Arizona — derived from magnetic-field measurements 120,000 miles beneath the sun’s surface — suggest that Cycle 25, whose peak is due in 2022, will be a great deal weaker still.
According to a paper issued last week by the Met Office, there is a 92 per cent chance that both Cycle 25 and those taking place in the following decades will be as weak as, or weaker than, the ‘Dalton minimum’ of 1790 to 1830. In this period, named after the meteorologist John Dalton, average temperatures in parts of Europe fell by 2C.
However, it is also possible that the new solar energy slump could be as deep as the ‘Maunder minimum’ (after astronomer Edward Maunder), between 1645 and 1715 in the coldest part of the ‘Little Ice Age’ when, as well as the Thames frost fairs, the canals of Holland froze solid.
Yet, in its paper, the Met Office claimed that the consequences now would be negligible — because the impact of the sun on climate is far less than man-made carbon dioxide. Although the sun’s output is likely to decrease until 2100, ‘This would only cause a reduction in global temperatures of 0.08C.’ Peter Stott, one of the authors, said: ‘Our findings suggest a reduction of solar activity to levels not seen in hundreds of years would be insufficient to offset the dominant influence of greenhouse gases.’
These findings are fiercely disputed by other solar experts.
‘World temperatures may end up a lot cooler than now for 50 years or more,’ said Henrik Svensmark, director of the Center for Sun-Climate Research at Denmark’s National Space Institute. ‘It will take a long battle to convince some climate scientists that the sun is important. It may well be that the sun is going to demonstrate this on its own, without the need for their help.’
He pointed out that, in claiming the effect of the solar minimum would be small, the Met Office was relying on the same computer models that are being undermined by the current pause in global-warming.
CO2 levels have continued to rise without interruption and, in 2007, the Met Office claimed that global warming was about to ‘come roaring back’. It said that between 2004 and 2014 there would be an overall increase of 0.3C. In 2009, it predicted that at least three of the years 2009 to 2014 would break the previous temperature record set in 1998.