OT - Even it that thesis is 100% correct, the amount of solar radiation affecting the earths surface has increased due to a depletion of ozone in our stratophere, something they fail to mention. Ozone is our natural sunblock... and it is decreasing mainly at the poles. Why? You can find some answers here;

http://www.science.org.au/nova/004/004key.htm

To say that more solar radiation is reaching the earth`s surface because of less pollution is misleading and most likely false.