Saturday, December 20, 2008

Coal's causing global warming – and we're about to run out of coal?

I'm a few days late on this, but Wired has two articles up that challenge popular conceptions of where global warming is coming from, and how likely exogenous factors are to put a sudden halt to it.

The first article's idea is well summed-up in the headline: "Oil Is Not the Climate Change Culprit – It's All About Coal." Evidently this idea is pretty popular among scientists, who argue that oil consumption is not causing global warming:

While both Kharecha and Caldeira stopped short of saying that the world's oil usage didn't matter, Caldeira seemed to capture their joint sentiment when he called the combustion of oil a "second-order effect."

The second article takes this fact and turns it into an argument that global warming might come to an abrupt end: "World Coal Reserves Could Be a Fraction of Previous Estimates." This is based on a study done by Dave Rutledge, chair of Caltech's engineering and applied sciences division, who argues that the discrepancy between his estimates and other estimates is that countries were often interested in inflating their coal reserves rather than accurately measuring them, though he doesn't explain why non-governmental experts haven't produced surveys coming to similar conclusions.

If "peak coal" really is coming soon, this means that many climate change models are way too pessimistic:

The Intergovernmental Panel on Climate Change uses economic models that assume that the world will not run out of coal. Some IPCC scenarios show 3.4 billion tons of coal being burned just through 2100. That's more than five times what Rutledge thinks will be possible — and a good deal higher than the WEC's estimate for recoverable coal reserves, too.

But, as a scientist notes at the end of the article, the end of coal doesn't necessarily mean the end of global warming – a lot depends on what coal is replaced with:

"Peak Oil and peak gas and peak coal could really go either way for the climate," Kharecha said. "It all depends on choices for subsequent energy sources."

2 comments:

Bhuvan Chand said...

i really impress with you blog and plz keep writing for this blog. i also start collection of information about causes of global warming in my blog.

Anonymous said...

Man-made global warming is caused by the imagination of man. It certainly does not come from science: there is no evidence for it.

It is all politics, really. Why else would you have the Kyoto Accords having some nations increase "greenhouse gas" emissions?