Atmospheric conditions like volcanic eruptions, the suns output, the proxity of the Earth to the sun (Milankovitch cycles) are all part of the models used to examine climate change.
These models correctly predict past climate changes but they don't work for the current one. That only works correctly when you factor in human emissions of greenhouse gasses.
Do you think that the large research facilities with supercomputer simulations and thousands of research hours haven't just waved their hands and said "Lets just ignore volcanoes"?
You'll have to come up with something a bit more revolutionary than that.
The Cosmic rays idea was a bit more revolutionary - unfortunately that turned out to be simply wrong
http://environment.in...1.html?thread=2375949