Conclusive proof that human activity the cause of global warming

Rush Limbaugh actually is a big fat idiot after all.

Rush is a strong opponent of human-induced climate change.

Well, there is now conclusive proof that climate variability has exceeded natural variations.

Of course, like holocaust deniers, Rush will point to the scientists as being some liberal cabal of pointy-headed intellectuals and are therefore not to be believed.

Here's what I say to that: If you're standing on a train track with lights approaching and horns blowing, you can deny the fact that a train is coming up until you get run down.

Or, you can take the evidence and take action.