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OT: Moorabal/Lal Lal wind farm 9-Jul-2009 At 11:47:22 AM evanbb

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On 7/07/2009 ajfclark wrote:
>There's something that's been bothering me about all these graphs...
>
>It's my understanding that it takes some time for anything released into
>the atmosphere to actually make it's way up and spread out and so on, right?
> With CFCs they said that the ozone hole would continue to grow for some
>time because even when we stopped releasing them it'd take some time for
>them to stop accumulating in the atmosphere/stratosphere/whatever level
>it was, right?
>
>So shouldn't these graphs also be allowing for that lag time? Shouldn't
>the temperature graph for say 2000-2010 be graphed against the CO₂
>from some 10 year period somewhat earlier?

To be honest, I just don't know. But I'll speculate wildly if you think it'll help?

Ozone depletion and warming are really 2 quite different mechanisms. The ozone hole gets depleted by CFCs breaking the fancy Ozone bond and making it just normal, garden variety O2 (I think). The lag in that finishing is not so much the time it takes to get up there, but that it takes so frigging long for natural processes to destroy the (primarily) CFCs that are doing the damage.

The AGW mechanism is different. Sun comes in as UV (short wavelength) energy mostly. Some bounces off the atmosphere, some bounces off clouds (and I think it bounces off clouds as apposed to water vapour, because clouds consist of liquid water droplets), some bounces off the earth it self. CO2 doesn't interract with these short wavelength photons. However, once it bounces off the earth, it doesn't so much bounce, as get absorbed, then re-emitted at a different wavelength. This longer wavelength does interract with CO2, and stores energy, which contributes to stored heat. So, CO2 should start having an affect as soon as it's emitted, rather than a lagging one. Any molecule between the ground and the top of the atmosphere has the potential to trap heat.

Here's a pretty good description of this:
http://ipcc-wg1.ucar.edu/wg1/FAQ/wg1_faq-1.3.html