Over the span of 11 years images from the Solar and Heliospheric Observatory (SOHO) spacecraft show the Sun's activity vary in intensity as magnetic field lines that are wound and tangled inside the Sun periodically break through to the surface.
Solar Cycle 24 began in early 2008 (image left), but has shown minimal activity through early 2009 (image right). The small changes in solar irradiance that occur during the solar cycle exert a small influence on Earth's climate, with periods of intense magnetic activity producing slightly higher temperatures, and solar minimum periods such as that seen in 2008 and early 2009 likely to have the opposite effect.
Skeptics have been saying that global temperature rises might be due to changes in the sun, pretty much the ultimate "it wasn't us, a big boy did it," with a giant fusion reactor as the elusive culprit. Researchers have shown that this isn't the case and unlike the original claim, their work involves advanced computer models, a distinct lack of the word "might", and has been published in Science.
Carnegie Mellon University's Peter Adams along with Jeff Pierce from Dalhousie University in Halifax, Canada, have developed a model to test the controversial hypothesis that says changes solar activity are causing global warming.
The hypothesis they tested was that increased solar activity reduces cloudiness by variations in cosmic rays. So, when clouds decrease, more sunlight is let in, causing the earth to warm. Some climate change skeptics have tried to use this hypothesis to suggest that greenhouse gases may not be the global warming culprits that most scientists agree they are. They found that changes in the concentration of particles that affect clouds are 100 times too small to affect the climate.
Professors Peter Adams and Jeff Pierce did a bunch of things that those throwing around the solar excuse didn't:
a) They did detailed work analyzing the actual effects of such activity
b) They actually understood what such effects would really even be
c) They rigorously applied scientific procedures to this research, constructed computer models, and would have reported the results either away
d) They spent many, many years earning PhDs in scientific research and the title of "Professor."
We have to say, d) is our favorite.
The simulations show that the effects of cosmic rays from the sun are barely 1% of what they'd have to be to explain what we've seen. The scientists are even one step ahead of the "maybe-sorta" game, admitting their simulations can't account for everything that exists, because nothing could ever do that (including their opponents' arguments), but pointing out that nothing omitted or missed could skew the results enough to appreciably alter the results.
Posted by Luke McKinney with Casey Kazan.
Changes in the Sun are not causing Global Warming, Study Says http://www.sciencedaily.com/releases/2009/05/090511122425.htm
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