Humans were insensitive eco-spoilers even before the combustion engine!

Humans started causing global warming 5,000 years ago, UW study says

Global warming didn't start with the industrial revolution, but began 5,000 to 8,000 years ago with large-scale agriculture in Asia and extensive deforestation in Europe, according to new research by University of Wisconsin-Madison scientists.

Using powerful supercomputers and advanced climate models, the researchers concluded that methane and carbon dioxide - the building blocks of global warming - began rising with the introduction of rice cultivation and large-scale tree removal.

If only Al Gore had been there to stop them! Yeah, they'd probably have starved and died, but the planet would be safe!

Anyway, it’s not all bad:

The work of the UW team also shows that the build-up of greenhouse gases over thousands of years has prevented the start of a new glacial age.

Considering how cold it’s been already this year (and last year!), I think we should all be pretty damn glad those ignorant primitives were so far-sighted as to start emitting greenhouse gases when they did. Don’t you agree?

Now: compare that last excerpted paragraph with this one, from earlier in the story:

"I think that the take-home message is that this hypothesis shows that climates are extremely sensitive to small variations in greenhouse gases," said Steve Vavrus, a climatologist at UW's Center for Climatic Research.

If climates are “extremely sensitive,” then shouldn’t we be seeing a far greater effect from these thousands of years of human pollution?