Oliver Geden has suggested that I misrepresented him in my earlier post. Rather than explaining why, he tweeted one his papers and suggested I should read it, rather than base my views on short quotations. Well, I have, and still do not see where I’ve misrepresented him. However, I certainly don’t intend to misrepresent anyone, so I’m going to make some comments below and if anyone (including Oliver Geden) wants to explain what I’m getting wrong, feel free.
The key issue seems to be this
Ideally, scientific expertise for policymakers should meet two potentially conflicting standards at once: it should be scientifically sound and politically viable.
Well, if the scientific expertise is coming from active researchers, then I disagree. Natural/physical scientists aim to understand nature/physical systems. What they present should be independent of politics. How can they decide if what they present is politically viable? Whether something is politically viable, or not, should be determined – IMO – by our policy makers, not by those presenting the scientific evidence. So, that is my main issue with what Oliver Geden seems to be presenting. Either we disagree, or when he talks about scientific expertise he’s referring to a different group to those to whom I think he’s referring. If the latter, he could clarify.
However, the rest of Oliver Geden’s paper seems similarly confused. It’s as if he doesn’t understand the natural/physical sciences and thinks that this is some kind of negotiation between scientists/researchers (who are trying to “sell” something) and policy makers.
For example, he says:
For natural scientists, the situation seems to look relatively good at first glance. The basic concept of anthropogenic climate change is now generally accepted world-wide….
Why is this good for natural scientists specifically? We should all be pleased by this. Anthropogenically-driven climate change is a scientific reality, not an ideology. Scientists have not been trying to get people to accept this because it’s their preferred option; they’ve been trying to get people to accept this because there isn’t any viable scientific alternative. It’s good for all of us that this is now generally accepted.
He then says:
But how will natural scientists react to the growing political pragmatism? If it becomes more obvious that international climate policy is not derived from a global stabilization target, prominent scientists will be forced to choose between two equally inconvenient options. They could vigorously defend their original concept of planetary boundaries and global thresholds, which would be met with increasing dissatisfaction from politicians, policymakers, and public funding agencies. Or they could soften their stance on an exact threshold to ‘dangerous climate change’, perhaps by allowing for temporary temperature over-shoots or even higher stabilization targets.
What has this got to do with scientists? Scientists study systems and try to understand how they evolve and respond to change. In this context they can then present this information to policy makers who can use it to inform decision making. What policy makers might, or might not, accept has little bearing on them. They’re not trying to sell an ideology, they’re trying to provide scientific information.
If policy makers choose to ignore this, or choose to follow a pathway that scientists regard as potentially risky, it’s not scientists who have to accept this; it’s all of us. What policy makers might decide to do, or not do, does not influence physical reality. Scientists can soften their stance on an exact threshold to ‘dangerous climate change’ as much as they like; it isn’t going to influence where it actually is – if it does exist. We can, of course, settle for higher stabilisation targets if we wish. It will just change the likely impacts. I have no idea why he thinks natural scientists need to allow this. I want, however, to come back to the idea of temporary temperature over-shoots later, as I think this illustrates a lack of understanding.
He goes on with
A good example of the dilemma scientific policy advisors are facing can be seen in the concept of the emissions budget. It starts from a stabilization target — usually the 2oC limit set by the UN — that is used to calculate the maximum amount of greenhouse gases that can be emitted worldwide. This construct, which is a centerpiece of IPCC AR5, is much more rigorous than targets like ‘global emissions reductions of 50 percent by 2050’, and is intended to severely limit the options available to policy-makers. The later the global emissions peak is reached, and the higher that peak is, the greater the subsequent annual reduction rates will have to be in order to stay within the remaining budget.
Well, I don’t think this is true. An emission budget or global emissions reduction target, are simply two ways of looking at the same thing. If we have a warming target, then we can either approach this by thinking in terms of some level of emission reductions, or in terms of there being some kind of total budget that we should not exceed. How the system will respond does not really depend on how we choose to describe the possible future pathways. At the end of the day, there will be a limit to how much we can emit if we want to give ourselves some chance of keeping warming below some level. It’s as simple as that.
He then says something that I regard as very odd
But what if policymakers do not comply? What if emissions continue rising with no peak in sight? Again, scientific advisors face two equally unappealing options. They can either less relevant to policymakers or more pragmatic.
Why use the word “comply”? They’re the decision makers. Scientists are simply providing information that policy makers can essentially use as they see fit. The answer to this also seems obvious to me. If policy makers choose not to stay within the suggested budget, then we will warm more than if we did stay within the suggested budget, we will probably miss the warming target, and the impacts will probably be more severe. How scientists might choose to respond to this has no bearing whatsoever on what will actually happen. In what sense can they become pragmatic? The evidence doesn’t depend on what policy makers might decide.
He then spends quite some time talking about emission pathways that would require negative emissions if we are to have a chance of staying below 2oC. He suggests that these are regarded as unrealistic, but that scientists have been reluctant to speak out. He suggests that these somehow allow for weaker climate targets, despite relying on a potentially controversial, and untested, technology.
Let’s clarify something, though. Climate models actually work with concentration/forcing pathways. Therefore you can use a climate model to estimate what sort of concentration/forcing pathways would probably keep warming below 2oC. The associated emission pathways essentially come later. At the moment, a reasonable fraction of the concentration/forcing pathways that would keep warming below 2oC seem to require negative emissions in the future. If someone thinks that negative emissions are virtually impossible, or risky, they have two options.
- Argue for more drastic emissions reductions now, so as to avoid having to follow a pathway that will probably require negative emissions in the future.
- Accept that we will probably miss the warming target.
There isn’t some kind of third option where you send scientists away and say, come back with an emission pathway that doesn’t require more drastic emissions reductions now, doesn’t require negative emissions in the future, and that still gives us the same chance of staying within the warming target. Such an emission pathway does not exist. As far as I’m concerned, these negative emission pathways are being presented because what we’ve done to date (not enough) is making it more and more likely that such a pathway will be necessary if we are to keep within the warming target, not because scientists are trying to provide some kind of pathway that allows us to relax and continue as we are.
Now I want to come back to the comment about a temporary temperature over-shoot. If negative emissions are virtually impossible, or a risky thing to rely on, then presumably the best we can possibly do is get emissions to zero. However, if we get emissions to zero, the expectation is that it will simply stablise temperatures. In the absence of negative emissions, a temporary temperature over-shoot is not regarded as an option; it will simply be a higher temperature, not a temporary over-shoot. That Oliver Geden could suggest a temporary temperature over-shoot, while criticising negative emission pathways, might suggest he doesn’t understand the scientific evidence as well as maybe he should.
Oliver Geden’s paper finishes with
Valuable scientific knowledge will remain an important factor going forward, but it will by no means be the decisive factor. To start taking effective action, politicians and policymakers already know more than enough.
I agree that more than enough is known. What I dispute is that politicians and policy makers know more than enough; from what I’ve seen this is not self-evidently the case. I can accept the idea that it would be good if scientists could find effective ways to discuss the scientific evidence with policy makers, but the evidence is essentially fixed; no amount of pragmatism is going to change how our climate will respond to increasing anthropogenic forcings. Of course, the scientific evidence alone does not tell us what we should do; there are many other factors to consider.
However, if the decisions that are made turn out to be poor, it’s not going to be the fault of natural scientists. It will be the fault of those who were expected to consider all the evidence when making their decisions. In a sense this is one reason I find Geden’s framing frustrating, as it seems to be placing a great burden onto scientists, rather than placing the burden on politicians and policy makers, who should – IMO – be aiming to consider all the evidence. Natural scientists shouldn’t really need to work out how to get politicians to take notice; that is not their responsibility.
Anyway, I’ve written much more than I intended. If someone thinks I’m misrepresenting what Oliver Geden is suggesting, then feel free to explain why. I certainly don’t intend to do so, but having read his paper, I can’t see in what way I’m misrepresenting what he’s presenting.