It is interesting that cosmic rays that come from space help to make ordinary clouds, yet similar “rays” coming from the Earth’s own atmosphere are said to have no effect.

Radioactivity, whether natural or man made, does excite the nucleus of the atoms as well as the electrons within the atoms.

Duke University engineers have led the most detailed analyses of links between some lightning events and mysterious gamma ray emissions that emanate from earth's own atmosphere. Their study suggests that this gamma radiation fountains upward from starting points surprisingly low in thunderclouds. Counter-intuitively, these strong gamma outbursts also seem to precede associated lightning discharges by a split second.

http://www.physorg.com/news3959.html

The leader of Sun-climate research at the Danish National Space Center, Henrik Svensmark, puts together the findings reported by him and his colleagues in a dozen scientific papers, to tell how the climate is governed by atomic particles coming from exploded stars. These cosmic rays help to make ordinary clouds. High levels of cosmic rays and cloudiness cool the world, while milder intervals occur when cosmic rays and cloud cover diminish.

http://epw.senate.gov/public/index.cfm?FuseAction=PressRoom.Blogs&ContentRecord_id=0DF9B3CD-802A-23AD-4984-5AC0C6D42605

My prediction is that the climate changes will get worse, and I suspect that the cause is man made.