Experts in solar science, climate modeling and atmospheric science met in Boston at the annual meeting of the American Association for the Advancement of Science to discuss the possible link between variability in solar energy output and global warming here on Earth.
We do know that that our sun is a variable star: "It varies by about one-tenth of one percent" in energy output, according to David H. Hathaway, a sunspot specialist from NASA's Marshall Space Flight Center in Hunstville, Alabama. But that doesn't seem enough to explain observed climate change. In fact, according to Casper M. Ammann, a climate modeler at the National Center for Atmospheric Research in Boulder, Colorado, in the years since 1950, "there is no observed trend in solar radiation. The 11-year sunspot cycle has not been significantly abnormal."
In essence, he added, it's now very clear that the atmospheric changes being seen now — global warming — "have nothing to do with changes in solar activity. It's greenhouse gases. It's not the sun that is causing this [climate] trend."
The Earth's atmosphere — and its relationship to the sun's energy output — is so complex that even as warming began, "up until 1960 we couldn't see it." But now, he said, since warming has been confirmed, the world's climate scientists "are probably not overestimating the problem. It's probably worse than the estimates."
Ammann did add, however, that there is reason to hope that the most dire consequences can be avoided. Although it's clearly too late to avoid the heating of the earth's atmosphere, "we can substantially cut [it]" by severely reducing the amounts of carbon dioxide going into the air. "It is absolutely achievable," he said — if by mid-century societies can generate enough will to make the necessary changes.
In short: Grave situation. Can't blame the sun. There's hope if we get off our butts.
Lets do it.
See also: ::The 4 Stages of Global Warming Denial, ::Driving Another Nail into Climate Skeptics' Coffin, ::One More Climate Skeptic Argument Dims
Pic by Global Warming Art, Creative Commons BY-NC-SA