CLIMATE CHANGE: by Peter WestmoreNews Weekly
Lack of sunspots points to global cooling
, July 9, 2011
Having scared the hell out of a generation of young people by warning of imminent catastrophic global warming, climate alarmists are now facing the very real possibility that nature is about to apply its own corrective — with a period of global cooling.
Although Prime Minister Julia Gillard, Climate Change Minister Greg Combet and the Government’s climate advisers Professor Ross Garnaut and Tim Flannery have yet to catch up with it, there is a mounting body of evidence that the gradual upward temperature rise of the last three decades of the 20th century peaked, then remained stationary for about a decade, and is now falling — despite gradually increasing levels of CO2 in the atmosphere, which is supposed to trigger global warming.
What is triggering great interest is the behaviour of the sun. Solar observers had long noticed a correlation between sunspot activity and temperatures on earth, although the nature of the link is still hotly debated.
What is beyond dispute is that the Maunder Minimum, the period between 1645 and 1715 when there were fewer sunspots, coincided with the “Little Ice Age”, when all of Western Europe was covered with snow and ice for months on end. And the Dalton Minimum, another period of few sunspots between 1790 and 1820, coincided with another period of significantly colder weather.
Scientists have discovered that an earlier period of low solar activity, the Spörer Minimum (1460-1550), was also an unusually cold period. Conversely, periods of strong solar activity seem to coincide with warmer periods on earth.
The gradual temperature rise late last century coincided with three strong solar cycles. Solar cycle 21, which lasted from 1976-86, peaked with a sunspot number of 165.
The next solar cycle, which also lasted just 10 years, peaked at 159. Solar cycle 23, which lasted over 12-and-a-half years, ending in 2009, peaked at 121, while solar cycle 24 — which began early in 2009 — seems likely to reach just 70, the lowest for a century.
On top of this, solar physicists have discovered related changes which were the subject of discussion at a recent meeting of the American Astronomic Society.
A group of solar physicists from the US National Solar Observatory have noticed that a jetstream in the sun which normally precedes the rise in sunspot activity appears to have disappeared. Further, the strength of sunspots (separate from their number), seems to be diminished, and, if present trends continue, sunspot activity could cease altogether in 10 years’ time, as happened during the Maunder minimum.
The solar scientists concluded that the sun might be approaching an extended solar minimum, such as those which took place in the 17th and 19th centuries.
Quite apart from this, Dr David Evans, former consultant to the Australian Greenhouse Office (now the Department of Climate Change), has drawn attention to the impact of oceans, which cover over 75 per cent of the earth’s surface, on the earth’s temperature.
In a recent address in Perth, he said: “The earth has been in a warming trend since the depth of the Little Ice Age around 1680.
“Human emissions of carbon dioxide were negligible before 1850 and have nearly all come after World War II, so human CO2 cannot possibly have caused the trend. Within the trend, the Pacific Decadal Oscillation causes alternating global warming and cooling for 25-30 years at a go in each direction. We have just finished a warming phase, so expect mild global cooling for the next two decades.”
While many climate scientists are sceptical of the influence of the sun in global warming, instead blaming anthropogenic CO2, a prominent American climate scientist, Dr Roy Spencer, has recently changed his mind.
Before becoming a principal research scientist at the University of Alabama in Huntsville in 2001, he was a senior scientist for climate studies at NASA’s Marshall Space Flight Center, where he conducted their global temperature monitoring work with satellites.
Dr Spencer’s work with NASA continues as the U.S. Science Team leader for the Advanced Microwave Scanning Radiometer flying on NASA’s Aqua satellite, and he posts monthly global temperature data on his web site: www.drroyspencer.com
After reviewing data which showed that cosmic radiation from outer space promotes cloud formation, Dr Spencer wrote, “While I have been sceptical of [Dr Henrik] Svensmark’s cosmic ray theory up until now, it looks like the evidence is becoming too strong for me to ignore.”
Dr Svensmark argues that the intense radiation emissions associated with sunspots blanket the earth, reducing the amount of cosmic radiation hitting the earth, and reduce cloud formation. Conversely, reduced sunspot activity and lower electromagnetic radiation from the sun were accompanied by more cosmic radiation from space, more cloud cover and a cooler earth.
Svensmark’s controversial theory is a possible explanation for the correlation between the historical observation that reduced sunspot activity accompanies global cooling.
Chart caption: A graph showing the reconstructed Pacific Decadal Oscillation, over the past two millennia or so. The source is the US National Oceanic and Atmospheric Administration (NOAA).