www.eoearth.org/article/Solar_radiation


http://aip.org/history/climate/solar.htm
Quote:
Some experts persevered in arguing that slight solar changes (which they thought they detected in the satellite record) had driven the extraordinary warming since the 1970s. Most scientists expected that these correlations would follow the pattern of every other subtle solar-climate correlation that anyone had reported fated to be disproved by the following decade or two of data. Even if the contrarians were right, however, greenhouse warming was bound to swamp the solar effects as humanity emitted ever more gases. Willson, the leader of the satellite experts, explained that in the future,"solar forcing could be significant, but not dominant."(58*)
The import of the claim that solar variations influenced climate was now reversed. Critics had used the claim to oppose regulation of greenhouse gases. But what if the planet really did react with extreme sensitivity to almost imperceptible changes in the radiation arriving from the Sun? The planet would surely also be sensitive to greenhouse gas interference with the radiation once it entered the atmosphere. A U.S. National Academy of Sciences panel estimated that if solar radiation were now to weaken as much as it had during the 17th-century Maunder Minimum, the effect would be offset by only two decades of accumulation of greenhouse gases. As one expert explained, the Little Ice Age "was a mere 'blip' compared with expected future climatic change."


http://aip.org/history/climate/20ctrend.htm#M_46_

What I'm reading says that solar irradiance may or may not be increasing very slightly over the last several decades, but the change appears to be so small as to be close to undetectable. The models suggest that it could add slightly to the effects of greenhouse gas, but that it can't be responsible for the recent runup in temperature. But if you have better data, Duke, I'll read it.