Recent observations point to a strong link between “solar variability” – or fluctuations in the sun’s radiation – and climate change on Earth, while other research sees the sun as just one of many heavenly bodies affecting global warming in the later half of the 20th century.
Contrary to what has been stated in a “Summary for Policymakers” attached to the United Nation’s International Panel on Climate Change (IPCC) report -- and in subsequent press coverage of the report -- there is scant evidence in favor of human-caused global warming, according to geologists, astrophysicists, and climatologists who have released updated studies.
The IPCC report was issued most recently in February 2007.
An examination of warming and cooling trends over the last 400 years shows an “almost exact correlation” between all of the known climate changes that have occurred and solar energy transmitted to the Earth, while showing “no correlation at all with CO2,” Don J. Easterbrook, a geologist with Western Washington University in Bellingham, Wash., told CNSNews.com.
The isotopes located in Greenland’s ice core, along with layering features, make it possible to date and track some of the climate changes that have occurred, he explained. Consequently, he has identified about 30 warming and cooling cycles that have taken place reaching back over the past several hundred years.
“Only one in 30 shows any correlation with CO2,” he said. “So if you’re a baseball player with 30 at bats, that’s not a very good average.”
The ice core records also show that after the last Ice Age ended, temperatures rose for about 800 years before CO2 increased, Easterbrook pointed out in a recent paper. This demonstrates that “climatic warming causes CO2 to rise, not vice-versa,” he wrote.
“There is no actual physical evidence you can point to that would say CO2 is causing climate change,” he said in the interview. “If CO2 was causing global warming, you would be able to detect this warming in the lower part of the atmosphere (called the troposphere) but there is no warming here, so the answer for some is to look the other way.”
Unfortunately, the media at large is reticent to report on any evidence that contradicts human-caused global warming because there is a lot of money and political influence tied up with the theory, Easterbrook said.
Meanwhile, other scientists are beginning to attach themselves to the idea that the sun, not mankind, is primarily responsible for driving global warming.
Dr. Bruce West, the chief scientist of the U.S. Army Research Office’s mathematical and information science directorate, sees a strong link between the dynamics of the sun and the Earth’s ecosystem.
In the March, 2008 issue of Physics Today, West wrote, “The Sun could account for as much as 69 percent of the increase in Earth’s average temperature.”
Although it was long assumed that the sun was a constant star, one that did not experience any variability in its irradiance, this is not the case, Fred Singer, an atmospheric and space physicist, pointed out in an interview.
Solar variability – fluctuations in the sun’s radiation – directly affects climate change on Earth, in his estimation. Unfortunately, the IPCC has overlooked some of the most important factors concerning solar activity, Singer argued.
There are some significant solar changes involving solar wind, for instance, that have ramifications for Earth’s climate, but those solar changes are de-emphasized in the IPPC studies, he said.
Singer co-authored and edited a report released earlier this year entitled “Nature, Not Human Activity Rules the Climate” in which he challenges some the assumptions made by IPPC and elaborates on some of his alternative theories. The report was produced on behalf of the Nongovernmental International Panel on Climate Change (NIPCC).
“By disregarding or ignoring the very much larger changes of solar ultraviolet or of the solar wind and its magnetic-field effect on cosmic rays and thus on cloud coverage, the IPCC has managed to trivialize the climate effects of solar variability,” Singer’s non-government report states.
Singer, in concert with some of his colleagues on the report, have identified cosmic rays as a primary factor driving climate change on Earth. Cosmic rays are high-energy particles of extraterrestrial origin that collide at almost the speed of light with atoms in the upper atmosphere of the earth.
The hypothesis is underpinned by the idea that variations in the sun’s irradiance – electromagnetic energy emitted by the sun that reaches earth’s surface – translate into climate changes on Earth in two key ways: 1) cosmic rays create either more or fewer low, cooling clouds in our planet’s atmosphere; and 2) ozone changes driven by solar activity in the stratosphere create varying degrees of heating in the lower atmosphere.
(Ozone refers to oxygen atoms that protect the planet from harmful ultraviolet radiation. Ozone occurs naturally in the stratosphere, which is the upper atmosphere.)
Willie Soon, a climate scientist based in Massachusetts, agrees that natural forces are largely responsible for driving climate change on Earth, but he has some reservations about the cosmic ray theory. Instead, he sees a mix of astronomical influences that include the sun and other heavenly bodies.
“It’s a beautiful idea and I’m open-minded about it, but in the end I don’t think cosmic rays are the ultimate answer,” he said. “For me what works is to look at the powerful phenomenon attached to how the earth goes around the sun. Very slight changes [in the orbit] can lead to changes in the seasons.”
Soon credits a mathematician named Milutin Milankovic from Yugoslavia (now Serbia) who formulated the “orbital theory of climate change” back during the World War II era for offering up an explanation that remains salient and relevant to this day.
“So the way this theory works, we do not look at the energy of the sun itself,” Soon said. “Instead we look at the way our earth is being pulled and tugged by bigger planets, including the sun and the most massive gas giants. This is how our orbit is changing. Seasons can be changed slightly and yet significantly by orbits being pulled and tucked.”
From this larger astronomical perspective it also is possible to measure warming and cooling cycles that impact Earth’s nearby neighbors, most notably Mars, Soon suggested.
There is data going all the way back to 1976 that show Mars has also experienced global warming. The Martian ice cap has been melting during the same time period that human-caused emissions have been identified as the culprit behind global warming on Earth, he said.
Soon acknowledges that the astronomical data is limited and that more research is required. Even so, for the moment, it is difficult to disprove the idea that heavenly influences are largely responsible for the warming trends over the past few decades, he added.
As it turns out, this warming trend could be over anyway, according to Easterbrook, the geologist from Washington State. A slight cooling period that began to take hold in 1998 could endure for the next 30 years, he forecasts.
A phenomenon known as the “Pacific Decadal Oscillation” (warming and cooling modes in the Pacific Ocean) points the way, in his view.
“It’s practically slam dunk that we are in for about 30 years of global cooling,” he said. Not something you will read about in the media.”