Wednesday, April 22, 2009

Nobody Knows (aka Whose Theory Is It?)

One of my pet peeves is the all-too-common practice of announcing a new scientific finding and immediately assigning it an AGW context, by which we are supposed to accept that this finding is "further proof" of AGW, when in fact it is proof of itself, nothing more. We cannot place a new scientific finding in context immediately, and we used to know that. Context takes time, but of course we have no time left, and so we must hurry up and assign context.

Which of course means that mistakes will be made, perhaps large mistakes.

Excuse me, but how does that lead to better public policy?

In other words, if we have to lie to get there, maybe we shouldn't be trying to get there.

In defense of another commenter I posted this comment to RealClimate in the "Yet more aerosols: Comment on Shindell and Faluvegi" thread.

I'm already being accused of trying to hijack the thread. Lots of thin skin over there, but to their credit, the moderators let the conversation happen.

Here is what I posted:

AGW is in fact a theory, that human activity, specifically land use changes and greenhouse gas emissions, will warm the planet. It is an adjunct to GW theory itself, which states that greenhouse gases are what allow planet Earth to maintain a constant temperature which is 33K above what it would otherwise be.

And to those who think this is a public policy nuance, you will need to reconsider that misguided notion.

This is the heart of the matter.

There is no question in most of our minds that AGW Theory is basically correct: short term climate sensitivity to a doubling of CO2 is 3*C+/-1.5*C. There is strong geological evidence that such an increase will cause significant sea level rise.

Stop there.

Every other “theory” (hypothesis, model result and so forth) is a guess. It is likely a highly educated guess, but who can say: in the year 2100 will there be more or less livable land mass than there is today? Will there be more or less food? Easier or more difficult shipping and transport? Will humans do poorly or maybe will they be better off?

That’s where the doomsday scenarios come in. More desert, more storms, more severe storms, and on and on and on, mass extinction and on and on and on.

That was the original commenter’s point, and I don’t know why it’s so hard to see, I honestly don’t.

I have news for you: we’re all going to find out. In 2100 we will no longer be burning fossil fuels at anywhere near today’s levels, but by then atmospheric CO2 will be 500 or higher, because even after we stop contributing to the rise, the oceans will, the permafrost will, the lake beds will and so forth. It is as inevitable as it is inexorable.

So we will see sea level rise, for sure, and some of today’s low lying lands will become bad places to live, and there will be mass migrations and certainly heavy loss of life. Again, I say: inevitable. What will emerge from that period?

For all we know, a more vibrant planet and a more compatible and sustainable human footprint. Perhaps man and all other life will simply find a way to adapt to a planet where average seasonal temperatures are a few degrees higher than they are today.

In any case, nobody knows, and the skeptics know who the fool is in that equation.