Saturday, January 7, 2012

What we don't know about climate

From a comment by Robert Brown at WattsUpWithThat:
... What is the temperature that it would be outside right now, if CO_2 were still at its pre-industrial level?

I don’t think we can begin to answer this question based on what we know right now. We can’t explain why the MWP happened (without CO_2 modulation). We can’t explain why the LIA happened (without CO_2 modulation). We can’t explain all of the other significant climate changes all the way back to the Holocene Optimum (much warmer than today) or the Younger Dryas (much colder than today) even in just the Holocene. We can’t explain why there are ice ages 90,000 years out of every 100,000, why it was much warmer 15 million years ago, why geological time hot and cold periods come along and last for millions to hundreds of millions of years. We don’t know when the Holocene will end, or why it will end when it ends, or how long it will take to go from warm to cold conditions. We are pretty sure the Sun has a lot to do with all of this but we don’t know how, or whether or not it involves more than just the Sun. We cannot predict solar state decades in advance, let alone centuries, and don’t do that well predicting it on a timescale of merely years in advance. We cannot predict when or how strong the decadal oscillations will occur. We don’t know when continental drift will alter e.g. oceanic or atmospheric circulation patterns “enough” for new modes to emerge (modes which could lead to abrupt and violent changes in climate all over the world).

Finally, we don’t know how to build a faithful global climate model, in part because we need answers to many of these questions before we can do so! Until we can, we’re just building nonlinear function fitters that do OK at interpolation, and are lousy at extrapolation.
Yet many scientists, most mainstream journalists, most politicians and government bureaucrats, many millions of  ordinary people, Al Gore and many other flakes remain utterly convinced that AGW is a proven threat to the planet.  And there's a much longer list of things we don't understand about climate.


Anonymous said...

It's 11 degrees in Edmonton today. I am sure climate change has nothing to do with it.

Deno said...

2 years ago Edmonton international airport reported a temp of -52 C, I'm sure global cooling has nothing to do with it.

One warm or very cold day in January proves nothing idiot!


Alex said...

We are postulating about a possible variation of 0.6C due to a change of 0.01% in the atmospheric composition when even the variation from day to night, in a span of a few hours, we experience a MEASURED variation three orders of magnitude higher.
As for me, I know whom to believe and not to believe. Its as clear as crystal.

Alain said...

It should be self evident that when the "scientists" cannot explain climate change in the past, they cannot claim with any credibility (scientific rather than political) future climate change. The same applies to CO2, which at several times in the past was much higher than at present and this was prior to any industrial revolution, and in fact was also the case prior to the arrival of man.

That the climate changes is nothing new, what is new is this global hoax claiming that we have the ability to affect it. Other than being a successful money generating scam, it is meaningless.

JR said...

"...successful money generating scam..." is right!

And what's really disturbing is that our governments have taken huge gulps of the Kool-Aid. To see how committed the BC government is, for example, search its web-pages for "climate change" - there are thousands of page hits with "carbon tax" being a big theme.

Alain said...

Yes, you are right and it is unacceptable. They, the governments, just cannot resist another cash cow, so we have to make it very clear that we shall not accept them milking us for fairy dust either.