The man is dangerous
This loony scientist-turned-climate-activist is reckless with science and his unfounded claims of peril are a threat to public order. Even his followers cannot believe he really said the oceans will boil, but here is the evidence. Should you not believe my biased sceptical transcript, just read his lips.
James Hansen: The Runaway Greenhouse Effect (video posted Jan 10, 2012)
At 1:55 (the link goes straight there) Hansen poses the question:
What is the runaway greenhouse effect?
Which he answers concisely and unambiguously:
That means once the planet gets warmer and warmer then the oceans begin to evaporate, and water vapour is a very strong greenhouse gas, even more powerful than carbon dioxide, so you can get to a situation where it just… the oceans will begin to boil and the planet becomes so hot that the ocean ends up in the atmosphere and that happened to Venus. That’s why Venus no longer has carbon in its surface. It’s atmosphere is made up of… basically of carbon dioxide because it had a runaway greenhouse effect.
Up to this point, you might reasonably claim (as his believers will, because they don’t want to think that he’s loony) that Hansen is merely exaggerating the possibility of runaway heating, for drama, without intending that anyone should think it could actually happen. Well, don’t believe it, because he now says that the Earth WILL BE DESTROYED by runaway warming caused by our carbon dioxide emissions if we do nothing to stop it. He spells it out:
Now the Earth, it can go unstable either toward a cool climate or toward a hot climate and the Earth has had a runaway snowball earth situation. This happened most recently about 700 million years ago. The Earth froze all the way to the equator, so the runaway situations can occur. We’ve never had a runaway greenhouse effect, because if we did, that would have been the end. Once… that’s a permanent situation. In the case of a snowball earth, when the Earth becomes ice-covered, then the planet can escape from that situation because volcanoes continue to go off, but the weathering process is greatly reduced. So volcanoes put carbon dioxide into the atmosphere and it builds up more and more until there’s enough to melt the ice. But we can’t push the planet off of the runaway greenhouse end of it, that’s… that’s the end for everybody if we do that.
So the end of the world is the first loony part of his climate “science”. But there’s a second loony thing: it could happen within a century. He maintains that the planet’s ice sheets could melt that quickly just from our emissions of greenhouse gases. So the Antarctic ice cap (2000 to 4000 metres thick) and the Greenland ice cap (3000 metres thick) could both be gone within a century—but not according to any scientific study. Estimates I’ve seen are far more conservative and range from about two thousand to ten thousand years and even longer. The amount of warming we might be causing is very small and in fact there’s no proof that we cause any detectable warming at all.
Don’t let this idiot near any important committee or panel. Like, say, the Inter-governmental Panel on Climate Change or the US House of Representatives. Oh, too late.