Has anyone heard of Global Dimming and if so what are your thoughts on it??

[Dark Razor]

What about the Ice Age? And before that, it was warm. After the Ice Age, it also became warm again. I suppose this happened because of cavemen releasing toxic chemicals into the atmosphere (aside from methane)?

The thing is, naturally ocurring fluctuations of climate do not disprove human-caused global warming. Human influences are on top of the naturally occuring phenomenon and cause a very rapid change in temperature that has likely not happend before (this fast), and may tip the system off balance with unforeseeable consequences.

 

[Lateralus]

What about the Ice Age? And before that, it was warm. After the Ice Age, it also became warm again. I suppose this happened because of cavemen releasing toxic chemicals into the atmosphere (aside from methane)?

Your error was stating "for no reason". There is a reason. We just don't always know the reason to a definite degree of certainty. Earth's climate is very complex, so our models are severely lacking.

 

[sundowning]

What about the Ice Age? And before that, it was warm. After the Ice Age, it also became warm again. I suppose this happened because of cavemen releasing toxic chemicals into the atmosphere (aside from methane)?

You're right - in fact, twenty cycles have been counted in marine sediment over the past 2 million years, one per every 100,000 years. The best explanation at present is Milankovich Cycles. Thing is, while this indeed a change in climate, it is not 'climate change' - a spike in CO2 levels coinciding with the industrial revolution and over a period of a couple hundred years does not coincide with the mechanisms behind the glacial/inter-glacial periods with a 100,000 year cyclicity.

Long story short: there's always a reason.