Unsettled science: Frank Hill of the National Solar Observatory: "the connections between solar activity and climate are still very poorly understood"

But wait a minute:  How, specifically, do you go about writing a reliable climate model while openly admitting that we don't understand really important influences like the sun and clouds?

Scientists see sunspot hibernation but no Ice Age | Reuters

But contrary to some media reports, this does not mean a new Ice Age is coming, Frank Hill of the National Solar Observatory said in a telephone interview.
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How strong a connection is there between a Little Ice Age and a Maunder Minimum? "Not as strong a connection as people would like to believe," Hill said by phone.
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Several websites and blogs have argued that the potentially cooling influence of a lower level of sunspot activity could cancel out the warming caused by human activities that generate climate-warming greenhouse gases. Hill disputed this.

"In my opinion, it is a huge leap ... to an abrupt global cooling, since the connections between solar activity and climate are still very poorly understood," he said in an e-mail.