A global cooling consensus

Solar activity is now falling more rapidly than at any time in the last 10,000 years

In the last two years, the scientific community’s openness to examining the role of the Sun in climate change – as opposed to the role of man – has exploded.

By Lawrence Solomon

In the 1960s and 1970s, a growing scientific consensus held that the Earth was entering a period of global cooling. The CIA announced that the “Western world’s leading climatologists have confirmed recent reports of detrimental global climatic change” akin to the Little Ice Age of the 17^th and 18^th centuries, “an era of drought, famine and political unrest in the western world.” President Jimmy Carter signed the National Climate Program Act to deal with the coming global cooling crisis. Newsweek magazine published a chilling article entitled “The Cooling World.”

In the decades that followed, as temperatures rose, climate skeptics mocked the global cooling hypothesis and a new theory emerged — that Earth was in fact entering a period of global warming.

Now an increasing number of scientists are swinging back to the thinking of the 1960s and 1970s. The global cooling hypothesis may have been right after all, they say. Earth may be entering a new Little Ice Age.

“Real risk of a Maunder Minimum ‘Little Ice Age,’” announced the BBC this week, in reporting startling findings by Professor Mike Lockwood of Reading University. “Professor Lockwood believes solar activity is now falling more rapidly than at any time in the last 10,000 years [raising the risk of a new Little Ice Age] from less than 10% just a few years ago to 25-30%,” explained Paul Hudson, the BBC’s climate correspondent. If Earth is spared a new Little Ice Age, a severe cooling as “occurred in the early 1800s, which also had its fair share of cold winters and poor summers, is, according to him, ‘more likely than not’ to happen.”

During the Little Ice Age, the Sun became eerily quiet, as measured by a near disappearance of the sunspots that are typically present. Solar scientists around the world today see similar conditions, giving impetus to the widespread view that cold times lie ahead. “When we have had periods where the Sun has been quieter than usual we tend to get these much harsher winters” echoed climatologist Dennis Wheeler from Sunderland University, in a Daily Express article entitled “Now get ready for an ‘Ice Age’ as experts warn of Siberian winter ahead.”

Scientists at the Climate and Environmental Physics and Oeschger Centre for Climate Change Research at the University of Berne in Switzerland back up theories that support the Sun’s importance in determining the climate on Earth. In a paper published this month by the American Meteorological Society, the authors demolish the claims by IPCC scientists that the Sun couldn’t be responsible for major shifts in climate. In a post on her website this month, Judith Curry, Chair of the School of Earth and Atmospheric Sciences at the Georgia Institute of Technology, all-but mocked the IPCC assertions that solar variations don’t matter. Among the many studies and authorities she cited: the National Research Council’s recent report, “The Effects of Solar Variability on Earth’s Climate,” and NASA, former home of global warming guru James Hansen.

As NASA highlighted in a press release in January of this year, in citing the NRC report on solar variations: “There is, however, a dawning realization among researchers that even these apparently tiny variations can have a significant effect on terrestrial climate.” To bolster the argument that solar activity could explain the Little Ice Age as well as lesser changes, NASA then listed some dozen authorities, including Dan Lubin of the Scripps Institution of Oceanography, whose research on other sun-like stars in the Milky Way suggest that “the Sun’s influence could be overpowering.”

In the last two years, the scientific community’s openness to examining the role of the Sun in climate change – as opposed to the role of man – has exploded. Scientists are now rediscovering earlier works by scientists at the Danish National Space Center who as early as the 1990s published peer-reviewed articles demonstrating the Sun’s role in climate change. And by scientists at the Russian Academy of Sciences’ Pulkovo Observatory, whose predictions in the last decade that global cooling would start in this decade are looking especially prescient.

All will be rediscovering the science of the 1960s and 1970s, which even earlier sounded the alarm on the coming period of global cooling. Those early scientists expected the cooling trend of the 1960s and 1970s to relent for several decades, as it in fact did. “None of us expected uninterrupted continuation of the trend,” explained Columbia University’s George Kukla in 2007, whose 1972 letter to the president triggered the U.S. government’s decision to take immediate action on the threat of global cooling.

Global warming always precedes an ice age, Kukla explained. The warming we saw in the 1980s and 1990s, in other words, was expected all along, much as the calm before the storm.