To be Fair: Global Warming May not be caused by the Sun

I want to be fair and open minded in the Climate Change debate. A recent study is indicating that the Sun may not be a cause of Climate Change.

Now, the finding doesn't make sense to me since it is counterintutive that more heat from the sun should cool the earth. The vague reasoning about the the earth not be affected due to the ocean's ability to absorb and retain heat needs to be explained a little bit more. I would think that if the oceans are preventing the Earth from warming because of the Sun, then wouldn't they work similarly for warming caused by man?

I still have questions that cause me to be skeptical. There is no "man-made" explanation for the Medieval Warming period between 800-1100 when the Vikings were able to farm areas of Greenland. What did man do to cause the Little Ice Age from about 1300-1850?

Of course, as I have said before, I believe that global warming is happening. But we have to be careful with what is causing it. Each side want to say it is ONLY cyclical/solar activity/natural process or it is ONLY human activity. As with a lot of things, I say that truth lies somewhere in the middle.