Solar scientists are finally overcoming their fears and going public about the Sun-climate connection
Four years ago, when I first started profiling scientists who were global warming skeptics, I soon learned two things: Solar scientists were overwhelmingly skeptical that humans caused climate change and, overwhelmingly, they were reluctant to go public with their views. Often, they refused to be quoted at all, saying they feared for their funding, or they feared other recriminations from climate scientists in the doomsayer camp. When the skeptics agreed to be quoted at all, they often hedged their statements, to give themselves wiggle room if accused of being a global warming denier. Scant few were outspoken about their skepticism.
Scientists, and especially solar scientists, are becoming assertive. Maybe their newfound confidence stems from the Climategate emails, which cast doomsayer-scientists as frauds and diminished their standing within academia. Maybe their confidence stems from the avalanche of errors recently found in the reports of the United Nations Intergovernmental Panel on Climate Change, destroying its reputation as a gold standard in climate science. Maybe the solar scientists are becoming assertive because the public no longer buys the doomsayer thesis, as seen in public opinion polls throughout the developed world. Whatever it was, solar scientists are increasingly conveying a clear message on the chief cause of climate change: It’s the Sun, Stupid.
Jeff Kuhn, a rising star at the University of Hawaii’s Institute for Astronomy, is one of the most recent scientists to go public, revealing in press releases this month that solar scientists worldwide are on a mission to show that the Sun drives Earth’s climate. “As a scientist who knows the data, I simply can’t accept [the claim that man plays a dominant role in Earth’s climate],” he states.
Kuhn’s team, which includes solar scientists from Stanford University and Brazil as well as from his own institute, last week announced a startling breakthrough — evidence that the Sun does not change much in size, as had previously been believed. This week, in announcing the award of a ¤60,000 Humboldt Prize for Kuhn’s solar excellence, his institute issued a release stating that its research into sunspots “may ultimately help us predict how and when a changing sun affects Earth’s climate.”
Earlier this month, the link between solar activity and climate made headlines throughout Europe after space scientists from the U.K., Germany and South Korea linked the recent paucity of sunspots to the cold weather that Europe has been experiencing. This period of spotlessness, the scientists predicted in a study published in Environmental Research Letters, could augur a repeat of winters comparable to those of the Little Ice Age in the 1600s, during which the Sun was often free of sunspots. By comparing temperatures in Europe since 1659 to highs and lows in solar activity in the same years, the scientists discovered that low solar activity generally corresponded to cold winters. Could this centuries-long link between the Sun and Earth’s climate have been a matter of chance? “There is less than a 1% probability that the result was obtained by chance,” asserts Mike Lockwood of the University of Reading in the U.K., the study’s lead author.
Solar scientists widely consider the link between the Sun and Earth’s climate incontrovertible. When bodies such the IPCC dismiss solar science’s contribution to understanding Earth’s climate out of hand, solar scientists no longer sit on their hands. Danish scientist Henrik Svensmark of the Danish National Space Institute stated that the IPCC was “probably totally wrong” to dismiss the significance of the sun, which in 2009 would likely have the most spotless days in a century. As for claims from the IPCC and other global warming doomsayers who argue that periods of extreme heat or cold were regional in scope, not global, Svensmark cites the Medieval Warm Period, a prosperous period of very high solar activity around the year 1000: “It was a time when frosts in May were almost unknown — a matter of great importance for a good harvest. Vikings settled in Greenland and explored the coast of North America. On the whole it was a good time. For example, China’s population doubled in this period.”
The Medieval Warm Period, many solar scientists believe, was warmer than today, and the Roman Warm Period, around the time of Christ, was warmer still. Compelling new evidence to support his view came just in March from the Saskatchewan Isotope Laboratory at the University of Saskatchewan and Institute of Arctic and Alpine Research at the University of Colorado. In a study published in the Proceedings of the National Academy of Sciences of the United States of America, the authors for the first time document seasonal temperature variations in the North Atlantic over a 2,000-year period, from 360 BC to about 1660 AD. Their technique — involving measurements of oxygen and carbon isotopes captured in mollusk shells — confirmed that the Roman Period was the warmest in the past two millennia.
Among solar scientists, there are a great many theories about how the Sun influences climate. Some will especially point to sunspots, others to the Sun’s magnetic field, others still to the Sun’s influence on cosmic rays which, in turn, affect cloud cover. There is as yet no answer to how the Sun affects Earth’s climate. All that now seems sure is that the Sun does play an outsized role and that the Big Chill on freedom of expression that scientists once faced when discussing global warming is becoming a Big Thaw.