Someone who has just started following me on Twitter has linked to an “article” by a Dr Tim Ball, who’s got a doctorate, so he must be right. And who is an adviser to numerous climate-change-denying organisations with neutral sounding titles. But I’m sure that’s just a coincidence.

For more useful such debunkings, see:
http://bit.ly/5ExCzE &
http://rupertsread.blogspot.com/2009/11/scandal-over-hacked-climate-science.html
or check out some of the links at #cru and #climatechange on twitter.

Sigh.

Missing the point as usual.

There’s one area where the “science of climate change” is still very dodgy indeed. It’s in trying to work out what climate sensitivity is (usually defined as the temperature rise to come from a doubling of atmospheric CO2-e).

We know what the physics of the atmosphere tell us about this: 0.7 oC. Yes, that really is what physics tells us, it’s in the IPCC report.

We also know that there are positive feedbacks: less ice, lower albedo, higher temperatures, perhaps permafrost melting and giving off methane …..there’s lots of them. There are also negative feedbacks: higher plant growth for example, perhaps more carbon sequestered in soil….there’s lots of them.

What we don’t know is what is the nett balance of all of these positive and negative feedbacks. There are so many of them and we know so little about some/most/all of them that we end up having to guess that balance.

Which is what all those climate models are about: attempting to bring some information and rigour to our guesses. And if the people feeding information into those models have been playing hand waving games with what they’ve been feeding in then our guesses are a lot less informed than we would like. Possibly even biased by that hand waving.

This is what this leak/hack is all about. Not the physics of the atmosphere (which we know a lot about), not about climate change itself, but about how bad climate change will be for a given change in the composition of the atmosphere. And at least so far we find that the people supposedly working in a disinterested (in the scientific sense) manner are not disinterested but quite clearly biased.

To put it mildly, that isn’t what we want from people feeding information into a multi-trillion pound decision now, is it?

We know what the physics of the atmosphere tell us about this: 0.7 oC. Yes, that really is what physics tells us, it’s in the IPCC report.

This is true.

What we don’t know is what is the nett balance of all of these positive and negative feedbacks. There are so many of them and we know so little about some/most/all of them that we end up having to guess that balance.

But there has been a great deal of research on this and its now possible to say with a high levele of confidence that sensitivity is between 1.5 and 4.5 oC – that’s in the IPCC report as well. And scientists are increasingly confident that the actual level is around 3 oC.

A’ doooon’t know much abaaaart claaaamit chaynge, but a’ nooooo what a’ laaaaaayk…

Good science.

So, while these emails don’t appear to show a particular conspiracy (or that anthropogenic global warming is a MASSIVE LIE) they should still be taken very seriously if they do, indeed, show dishonesty. The work of these scientists is very influential, and thus, malpractice would be very dangerous (if, indeed, it does exist).

While any attempt to destroy material subject to a FOI request would have been illegal.

“And scientists are increasingly confident that the actual level is around 3 oC.”

Which is the James Annan line….which if true, means that we won’t have rnuaway warming and so can dial back a touch on the hysteria.

Maybe, but my understanding is that 3 oC could still be pretty serious.

Oh no, now Newton’s been rumbled!

http://carbonfixated.com/newtongate-the-final-nail-in-the-coffin-of-renaissance-and-enlightenment-thinking/

Maybe, but my understanding is that 3 oC could still be pretty serious.

Indeed – especially considering that that’s a global average.

Tim – “runaway” is what happened to Venus. It’s not going to happen here, and I’m willing to bet money that you have never actually heard a reputable climate scientist so much as suggest that it’s possible. Hell, even James Lovelock doesn’t go anywhere near that far, and he’s well beyond the outer reaches of mainstream climatology. You may have encountered various journos / activists / loonies misusing the term.

“You may have encountered various journos / activists / loonies misusing the term.”

Indeed but somewhat sadly it’s them that are driving the political response.

On both sides, unfortunately…

Dunc, my impression as an interested but entirely non-scientific observer is that a two-degree increase is thought to be the trigger for grave changes in the climate, if not for runaway warming. Is that utter bollocks then? Where has this noise about the significance of two degrees come from?

Well, two degrees is generally held to be the point at which the likelihood of really nasty adverse effects and other potentially very nasty positive feedbacks (“methane burp”, “clathrate gun”, that sort of thing) starts seriously ramping up. It’s certainly not the trigger point for “runaway warming”, at least not in the sense that term is normally used in the scientific community (as far as I understand it).

What I’m saying is that yes, there are some very nasty impacts out there, and yes, the likelihood of those things coming to pass increases dramatically once you get beyond a certain amount of warming, but no, we’re not going into full-blown Venusian-style climate runaway. You need to boil off the oceans for that to happen.

Thanks. In that case there is a wide gulf in understanding (no change there then) between what the non-scientists and the scientists *mean* by runaway warming, I think. I would have said that positive feedback mechanisms meant pretty much the same thing as ‘runaway’.

Just to be clear, I’m not arguing the point – just saying that there is a gaping hole where public understanding should be, and that this is something that really needs to be addressed.

Just to be clear, I’m not arguing the point – just saying that there is a gaping hole where public understanding should be, and that this is something that really needs to be addressed.

I really couldn’t agree more. Unfortunately, there is a significant lobby out there dedicated to spreading as much misunderstanding and confusion as possible…

Positive feedback leads to runaway only if the net feedback co-efficient is greater than 1 i.e. the feedback component is larger than the original signal itself. This is clearly not the case with Earth’s climate, or it would have run away to the limit long ago. However, we know that there definitely is a significant positive feedback component simply from water vapour, or the Earth would be a good deal colder than it actually is.

Tim, glad to see you agreeing that 3 degrees centigrade of over-heating is quite feasible, if we are insane enough to continue with a BAU economy.
The point is that 3 degrees is enough, as laid out in detail in Lynas’s ’6 degrees’, to precipitate feedbacks that probably 5 or 6 degrees of over-heat inevitable. Leading to complete civilisational meltdown.
So: on the eve of Copenhagen, our situation as a species IS very parlous.

See http://www.opendemocracy.net/ourkingdom/rupert-read/real-scandal-in-hacked-climate-change-e-mails-controversy for my latest on the whole controversy.

“The point is that 3 degrees is enough, as laid out in detail in Lynas’s ‘6 degrees’, to precipitate feedbacks that probably 5 or 6 degrees of over-heat inevitable.”

Ah, no, you’re not understanding what “climate sensitivity” means. It means the total summation of all feedbacks, over time (and yes, centuries into the future).

So if climate sensitivity is 3 oC then that means that, if we double atmospheric CO2, at some point in the future, after all of the feedbacks have happened, the ice melting, the methane clathrate erupting, after all of this, then the total temperature rise will be 3 oC.

That’s what the phrase means: we already know what the result purely of the first round is: if atmospheric CO2 doubles then straight physics tells us that the warming will be 0.7 oC.

So what you (and Lynas) are arguing is that if some set of warming then leads to more positive feedbacks so that we get 6 o C of warming from a doubling of atmospheric CO2 then you are arguing that climate sensitivity is 6 oC (or more).

Which is a very extreme estimation, one not bourne out by any of the science I’ve seen (although I agree I’ve only seen what the IPCC presents to us).

The alternative is that in your claim about 6 oC you don’t actually understand the subject or the phrases being used: like climate sensitivity.

You did say you were a politician, didn’t you?

Well , AR4 estimates climate sensitivity as “likely to be in the range 2 to 4.5°C with a best estimate of about 3°C, and is very unlikely to be less than 1.5°C. Values substantially higher than 4.5°C cannot be excluded, but agreement of models with observations is not as good for those values.”

The main problem is that it’s currently unclear at what point we start getting massive methane emissions from melting permafrost and destabilising clathrates. If those factors become significant then the positive feedback side could be quite non-linear, making high values for climate sensitivity much more plausible.

As one of the scientists invited to the conference which set up the new generation of UK climate models. Though our scientific brief prior was a ‘blue sky’ approach where anything and anyway could be considered.

When we got there the remit was to find a correlation between CO2 and climate change and the funders DEFRA wanted the methodology to be compatible with the existing Hadley Centre models. Thereby in my opinion eliminating other methodologies which could have been more effective in obtaining a more realistic representational model of Earth system processes.

#18 Tim Worstall

I do have the full methodology of the total IPCC models. Over 1000 pages. If I remember correctly the affects of the methane you discuss are not included. This was on the basis as so little was known as they could not be quantified, they could not be considered.

This was the draft report though.