Strange Early Leave Color Change and Fall

I have noticed the leaves on some of the trees near and around my house have been changing color and falling off recently.  I have also received confirmation that this is happening elsewhere along the east coast. Normally leaves can do this if the weather is dry or temperatures are well below average. However these are not contributing factors where I live.  So I began to look into the amount of solar radiation the surface has received this summer. Plants are dependent on solar radiation for photosynthesis to produce "food". During Autumn the amount of solar radiation the surface receives decreases along with the temperature (of the surface) causing plants to stop replenishing the chlorophyll in the leaves which creates the color change in fall. Because temperature and precipitation don't necessarily apply, I believe that decreased solar radiation is causing this leave change. This could occur due to multiple factors like volcanic ash in the atmosphere, increased cloud cover, the sun itself, or air pollution/other man made things. The two factors that I think apply the most to this situation are: increased cloud cover, and a sunspot maximum that could be the lowest in 100 years. The east coast has had an extremely wet summer, especially the southeast, and I, personally, haven't seen a cloudless day in a very, very long time. Also, on a cloudy day the surface receives only about 1/3 the amount of sunlight it would get on a sunny day. Sunspots, when facing the Earth can result in more solar radiation reaching the Earth than the sun without sunspots. The plants, who were most likely used to conditions other than the two I just described probably assumed that because they were receiving less solar radiation, that it was fall and time for the leaves to change color and fall off.