Tim Lenton is silly

timlenton However, I'm inclined to think that he isn't a tosser, just naive (as someone said, I don't think Tim understands the policy world very well). He looks a bit naive in his picture, doesn't he? And that is a sure-fire way to tell. But maybe that is me being naive. Well, let me tell you and you can make up your own mind.

Assuming you can be bothered, go off and read his piece in Nature: 2 °C or not 2 °C? That is the climate question (you ought to; please don't rely on my biased reporting of him :-). Tim has a laudable aim: he wants to ensure that global efforts to tackle the climate problem are consistent with the latest science. But alas he immeadiately goes off the rails, by talking about the

target to limit the global temperature rise to 2 °C above the average temperature before the industrial revolution...The target is linked to the United Nations Framework Convention on Climate Change (UNFCCC), which aims to "prevent dangerous anthropogenic interference with the climate system"

But note the rather weaselly words "linked to". Where exactly is the scientific basis for 2 oC? Tim is very interested in making our politics consistent with the science, so why isn't he mentioning it? Is he, perhaps, continuing the rather dishonourable tradition of pretending that because lots of people have taken 2 oC for granted, then it must have a solid basis? I don't think it has such as basis, and have said so before.

Continuing, Target setters need to take into account all the factors that threaten to tip elements of Earth's climate system into a different state... Well, Tim is a Tipping Points man, so it is no surprise to see him pushing his stuff. I still don't believe it though.

But anyway, onto the pointless naive policy suggestions: I suggest that the UNFCCC be extended. The climate problem, and the political targets presented as a solution, should be aimed at restricting anthropogenic radiative forcing to limit the rate and gradients of climate change, before limiting its eventual magnitude... The 2 °C target would translate into a radiative forcing of about 2.5 Watts per square metre (W mâ2), but to protect major ice sheets, we might need a tougher global target of 1.5 W mâ2". Wonderful: we can't meet the existing targets, because we lack political will. So rather than actually address that problem, let us fiddle the targets around and make them harder to meet. That will certainly be useful. Somehow or another this is supposed to connect to regional initiatives, in a way that didn't appear to make any sense but I didn't bother thinking about much as it was too obviously doomed to be very interesting.

Update: on reflection, I'm being too kind to Tim Lenton. This kind of get-yer-face-in-Nature stuff is malign.


* It's not telly if you watch it on a computer, say middle class people.


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I just wonder how this happens. If wrote a vacuous essay, attached my photo and sent it to Nature, would it also get published? Don't think so... but of course I'm not as pretty as Timmy. The last issue of Nature Geoscience contained a number of similarly uninformative articles. I guess its the pre-AR5 lull - and the editors are commissioning these essays just to keep climate change in the news. ...?...

[I think you're prettier. But, are your eyes as blue? -W]

The specific phraseology and figures may be sub-optimal, and certainly the suggestion of shrinking a target that already isn't being taken seriously. But I thought society needed to act in the face of uncertainty. Therefore the POTENTIAL for substantially accelerated climate change should be considered by policymakers. Isn't that the bottom line? And people wonder why there's confusion over whether we need to act more quickly - there's still much quibbling (sans any acknowledgment of reasonable intent). Most people, especially policymakers, need something a bit less equivocal.

[" I thought society needed to act in the face of uncertainty" - yes, I quite agree: it does. And in the case of economics, or foreign policy, it very frequently does. If TL had said that, I'd have been happy. The naive/stupid approach he is using, though, is the "more of the same failed approach" stuff, and it will go nowhere -W]

Your [redacted], you haven't read his article properly at all. He acknowledges that 2C is utterly arbitrary and actually if you must know the 2C target came from early cost benefit economic impact studies done in the 1980's by Nordhouse where the choice was utterly arbitrary but ended up being coopted into the literature as some kind of consensus.

[If you want "imbecile" to be convincing, then spelling it correctly would be a good idea ;-). As to the substance of your comment: you are wrong. He nowhere acknowledges 2 oC as arbitrary -W]

A 2 K increase is way, way too much.

By David B. Benson (not verified) on 06 May 2011 #permalink

"Ongoing negotiations for a new climate treaty aim to establish a target to limit the global temperature rise to 2 °C above the average temperature before the industrial revolution."

I understand why this may be a good idea but will it ever be possible to put a figure that baseline and bolt it down?

Given the existence of a propensity to contest everything, adopting a baseline that is open to claim, counter-claim, and new evidence, is hostage to fortune.


[No single number will ever make sense, given the uncertainties -W]

By Alexander Harvey (not verified) on 07 May 2011 #permalink

The 1.5C is based on the behavior of the ice sheets during the interglacials, and so does seem to have a firm footing. Irritatingly, it seems clear that we're already committed to exceeding it.

But is interesting to see one of that crowd giving a nod toward Hansen; it wasn't that long ago that Myles Allen publicly attacked him (in Nature again, IIRC).

By Steve Bloom (not verified) on 08 May 2011 #permalink

"[No single number will ever make sense, given the uncertainties -W]"

It is not the figure I take issue with but the baseline which is inherently unknowable.

Perhaps someone knows by how much the HADcrut3 1961-1990 climatology baseline is currently considered to be above "the average temperature before the industrial revolution"?

I think that fundamentally we are talking about modelled temperatures for which such an average temperature does exist. E.G. the average temperatures achieved by the pre-industrial forcing spin up phase.

So the proposition becomes one of restricting the rise in modelled temperatures to 2ºC above what they would have averaged if they had motored on from 1750 (or from whichever date the forcings start to vary) to 2050 without modification.

If that is what it means that is fine. It is a statistic that is well defined in principle.

Unfortunately I do not believe it is the statistic used for IPCC graphics which seem to favour a 1901-1950 climatology and do not indicate the pre-industrial forcing period temperatures, which may for all I know have a considerable spread and offset. So knowing the how much the 1901-1950 baseline is modelled to be above pre-industrial would be handy and if anyone can tell me where this value or set of values is lodged I will go look for it.

If we are talking about modelled values and are clear about that, a lot of concepts become meaningful. We could set targets to prevent various levels of modelled sea level rise, modelled deglaciation, modelled desertification, modelled rain forest decarbonisation, etc. Targets to achieve or prevent well considered and demonstrable modelled effects seem logical to me and may not necessarily driven by temperature as much as some other climatic disturbance.

The only quantified future that can currently exists is a modelled one. The only domain in which the 2050 ice and glacial patterns exist is the modelled domain. I am quite content to consider the merits of modelled policies or scenarios on the basis of modelled outcomes but I really do think it should be made clear to all concerned what we are talking about.

If we are not discussing future real world temperatures and other outcomes, which of course do not exist, but future modelled temperatures and outcomes which are quantifiable then that is coherent and meaningful.

I am content with trying to plot or navigate a future using computer models. But I think it needs to be made clear that modelled droughts are different in nature to real world droughts. We can attempt to navigate away from modelled droughts for they exist.

Non-correspondence between modelled events and real world events do not invalidate model use anymore than is the case with weather forecasts. Failure of the real world to confirm a modelled outcome is inevitable and we may need some luck in that respect.

We can never know how much real world pain, suffering and death we will cause or avoid but we can know how much modelled misery is down to our actions or in actions.

Here I expect I part company.

Those that believe in the value of modelling should be braver and clearer. By stating that the models chart the only futures that can be said to exist in any meaningful way. By giving force to the concept that modelled lives inherit rights from the real world and to kill them off is a culpable act.

So if the object is to prevent certain modelled consequences in a modelled world then that is fine by me, but I think it should be made clear that this is a different thing from preventing real world outcomes.


By Alexander Harvey (not verified) on 08 May 2011 #permalink

A better measure of success is the ratio of carbon-less energy in place to the total amount of energy necessary in 2050.

By Paul Kelly (not verified) on 09 May 2011 #permalink

Yss, Eli, and the simulators are getting pretty good.

I suspect that the best of the latest round of climate models may be able to allow us to answer a question that I think is significant.

Can we fly the planet.

Given that we may have some models that are controlled not by concentrations but by emissions from which the concentrations are modelled, we have an opportunity to practice flying the planet. We would make decisions and adopt strategies with the intention of avoiding certain unfavourable outcomes. As those strategies unfold they will need corrections based on information gleened from instrumentation. Requirements to adapt will emerge and tactics to achieve adaptation adopted.

I have a nasty feeling that the first attempts to navigate the climate future will end with crashing the planet even with the safest of pilots. You see I think that it may be a lot harder task than signing a few agreements and setting some targets. I think that we may find that mitigation is not a simple matter of setting a course and then sleeping at the controls. I also suspect that the requirements to adapt may occur in such an ill-mannered way that we will start projects and then abandon them as more urgent tasks are revealed.

I may be wrong, but if it turns out that we are ill-equipped and trained to fly planet Earth it might be nice to find out in advance.

I suspect that we may finally come to terms with some home truths. That natural variability is a nightmare not some get out of gaol free card. That we are institutionally ill-equipped to adapt in a timely manner in that it may require dictatorial powers to achieve those ends.

If we took the best of our climate simulators and the best ancillary models for population, industry, economics and ran them at a week for a year, I suspect that even the most well intentioned pilots would emerge dazed, shell-shocked, humbled and apologetic before 50 modelled years were up. But I do think that we could practice and learn.

I am deeply troubled by the current approach as I understand it. That we can somehow make agreements that are workable and will achieve favourable outcomes. I also worry that some of the necessary measures will be counter-intuitive or at least the timing of those measures. Mostly I worry that we will discover that we are flying almost blind, that it will not be obvious whether various mitigation stategies are working. That we will not foresee adaption needs in a timely fashion, and that embarking on them far ahead of time in a preemptive move will lead to a waste of resources as the regions or cities fall into decline for other reasons.

If it turns out that attempts to fly a simulated planet leaves us with a very different to-do list I think this would be very nice to know. And if, as is likely, we cannot make much progress in the real world, attempting to pilot the modelled Earth and having to react to particular realisations as they onfold is a possibility, and it might show that we need to build capacity in otherwise overlooked fields.


By Alexander Harvey (not verified) on 10 May 2011 #permalink


Do you agree with Hansen that nuclear power, which Hansen views as our best hope for replacing fossil fuels?

By Paul Kelly (not verified) on 10 May 2011 #permalink