Speaking of computer models, one thing that may work against CAGW is the fact that we are in an anomalous sunspot cycle. (notice the gap between latest actual numbers, and the predicted red model curve)
As many know who have been following the sunspot threads, we have been in an abnormally long period of little/no sunspots. Sunspots are an indicator of solar activity, and in particular of the strength of the solar magnetic field. The solar magnetic field acts to shield the Earth from interstellar cosmic ray particles. Ionizing particles act to promote cloud formation. The net effect is a global cool down when the Sun's magnetic field weakens.
Yep, I’ve been following that closely myself. It may be something more than a single anomalous cycle.
From another forum:
Here are a few things to keep in mind.
First, the consensus among solar astronomers is that Solar Cycle 24 (the new one) will be longer and weaker than Cycle 23, which was an extremely long and weak cycle. Long and weak cycles are generally associated with cooling trends.
Second, the solar wind remains at about half of historical levels, and no one knows exactly why. This causes cosmic rays to increase, and this year they are 20% stronger than ever observed before. There’s a hypothesis that they contribute to cloud formation, which would reflect more solar energy and cool the Earth.
Third, there’s a very interesting paper from the National Solar Observatory that predicts sunspots will vanish by around 2015, near the peak of the cycle. The reason is that, independent of the solar cycles, three measures of sunspot “quality” have been going down. In a nutshell, the core temperature is getting warmer, and if they get warm enough the sunspots will no longer be visible as dark spots. That’s a rather elegant explanation of the multi-cycle “no sunspots” periods during the Maunder Minimum.
http://wattsupwiththat.com/2008/06/02/livingston-and-penn-paper-sunspots-may-vanish-by-2015/
The article contains a link to the peer-reviewed paper.
The Maunder Minimum produced temperatures that were so cold, they could ice skate on the Thames River in England. Cold spells like that usually result in famine as well, since crops often don’t grow where they normally would. Think Canadian wheat...