“RCP8.5 is a world in which climate policy goes backwards, not one in which climate policy continues”: Jim Skea Co-Chair of the IPCC’s Working Group III on the latest updates from the forthcoming report.
In this episode of Cleaning Up, Michael Liebreich is joined by Jim Skea, Professor of Sustainable Energy at Imperial College London and Co-Chair of the Intergovernmental Panel on Climate Change’s Working Group III.
Jim tells Michael about the structure of the IPCC, what makes it unique, and how it’s in a strong position to influence governments to stick to climate action agreements. Michael then challenges Jim on the use of RCP8.5 – often referred to as the “business as usual” scenario – that Michael sees as hopelessly out of date. Jim finishes by hinting at the findings of the forthcoming IPCC report, due to be published no sooner than 2022.
Below is an abridged transcript of the conversation, edited for clarity.
Michael Liebreich: Jim, welcome to Cleaning Up. Could we start by introducing the Intergovernmental Panel on Climate Change? How does it work? What have you been doing? Just give an overview of how it's structured.
Jim Skea: The IPCC is unique. It’s important to remember the “I” in “IPCC” stands for intergovernmental, not international. Therefore, the governments are important. It works in cycles of 5 to 7 years; it can take time to get a new set of reports. During that period, hundreds of authors will work together trying to produce the latest reports on the up-to-date science of climate change. That science includes the impacts of climate change, and it includes all the means for getting emissions down, too. The IPCC doesn't do its own research, it reviews work that's been done by other people.
By the end, governments have signed up to the findings and they can't back away, which is what makes IPCC so powerful. It's glacially slow and it’s frustrating. But it's the outcome that matters. We’ve made a big difference over the last 3-4 years.
ML: Can you talk us through the work that the different Working Groups do?
JS: Working Group II looks at the impacts of climate change; penguins, polar bears, etc. They also look at vulnerability to climate change, and the measures you can take to adapt, such as genetic breeding of new crops that might be more climate resilient, building sea walls to protect against sea level rise, and so on.
The people in Working Group I think about what happens in the climate system, which includes the air, but also includes the oceans, vegetation and land cover. They look at the Paleo side, looking back hundreds of thousands of years, right through to the big, big models, where you press the button and it takes several months for the answers to come out, which simulate the effect of different levels of emissions on the climate. So that's what they do. Working Group III – we have the plumbers and the electricians who are given the job of figuring out how do we reach these objectives that our scientists have set for us. But in fact it’s a circular process, of course, because everybody claims they're the starting point and somebody else is the end point of it.
ML: To wrap it up: Working Group I: the planet. Working Group II: the impacts. Working Group III: emissions. What is the production cycle for the IPCC reports? And where are we in the cycle?
JS: The whole cycle takes 5 to 7 years. We should be done in 2022. In this cycle the Working Group I comes out first. They get their report approved. Then Working Group III is scheduled, followed by Working Group II. Then, there's something called a synthesis report produced at the end, which tries to be the one ring that binds them all together.
ML: What will the next report say? Will it be scarier or less scary?
JS: I can only talk to you about this in riddles because it is work in progress and we’re not supposed to talk about draft conclusions. Once governments have gone over it, and once it's been through another set of reviews, it might say something slightly different, or even very different from what the draft says now.
I can tell you the way the discussions go. Every time the IPCC produces a report, it says that limiting global warming to some level is challenging, but still possible. Then we produce a new report that says it's very challenging, but still possible. Then we up the qualification of challenging. Now, we are giving quite a lot of thought as to how we communicate where we are currently. The IPCC never said we have 12 years to save the world in the 1.5 Report a few years ago, but it was a good headline.
We thought two degrees was difficult. But we knew there were huge expectations about the report because the media had really wound themselves up on it. The UK government, for example, was waiting for the 1.5 report to increase the ambition of its Climate Change Act. Sometime in 2015 the planets completely aligned. You had the IPCC giving the evidence, you had the strength of the Paris Agreement. Then you had Extinction Rebellion, Greta Thunberg, et cetera, on the more civil society side. Everything lined up. The world is a completely different place from the one it was back five years ago before we started this.
But almost three years have passed, and we have not made the kind of progress that was anticipated when the 1.5 report said: This is the way we've got to get emissions down. It’s not been happening, so that has consequences for the type of messaging that will come out in the next report.
ML: Talking about more distant past. 20 years ago, a scenario called RCP8.5 came out which is often referred to as “business as usual” because it suggests an outcome if the world doesn’t act on climate change. I and others have investigated it and we're just baffled by why it's still regarded in any way serious, because it's far from any plausible pathway. But instead of saying, “it's not plausible, so we'll get rid of it,” what the system seems to have done is remove the requirement for plausibility.
JS: Let me neutrally say what you need to assume to think that an RCP8.5 pathway is plausible. You need to think that all the policies that have been put in place over the last three years are reversed. You need to think that all the wind turbines that have been installed are dismantled and we don't replace our photovoltaic cells. This is a world in which climate policy goes backwards, not one in which climate policy continues. A counter argument you will get from colleagues in the physical science community is that we run a risk of creating runaway positive feedbacks from release and natural releases of methane or carbon dioxide at higher levels of warming, meaning the RCP8.5 scenario is possible.
ML: But what I'm looking at is the energy related emissions. There's a 600 gigaton gap between a plausible path and the RCP8.5. When I look at the feedback’s literature, the worst I can find is a 114 gigaton potential positive feedback. Most of the impacts from feedbacks, as far as I can see, happen in the next century and further out, but that doesn't mean they're not important. However, pretending they can happen by 2100 feels to me un-robust and very easy to attack. The reason I care is because I want to be able to defend this stuff. And I'm worried that I won't be able to because it's just transparently a castle built on sand.
JS: There's a lot of lock-in in the scientific community: for things like IPCC, you could end up citing papers that were done several years ago, when the state of knowledge was different. So, there has always been a temptation, if you're in the Working Group II, impacts world, to say, look at a best case and a worst case. So, they have tended to take the most extreme RCPs. When they're doing the analysis, they'll take a relatively optimistic, the 2.6 one, which is lower, but they also take the 8.5 as the kind of high one, just to say in Working Group III. My fellow co-chair and I are trying to ban the use of the expression business as usual, because it's not particularly helpful. And when the next Working Group III reports comes out, we'll have something to say about the use of RCP8.5.
ML: Well, I'm delighted because meanwhile so many organisations, including the US National Climate Assessment and all of McKinsey's climate work, uses RCP8.5. But why produce a scenario that is not plausible in the first place? Knowing that whatever you say, people are going to abuse it and treat it as the baseline and business as usual. And then you can say ‘it says on page 72 of Working Group III, that you shouldn't do that’. But you know, it says you can't compare RCP 4.5 with 8.5. And yet the US National Climate Assessment 2017 does exactly that. So if I talk to your colleague who chairs Working Group II, will they use, refer to in any way papers that use RCP8.5 as effectively business as usual baseline or will they strike those out of the record and pretend they don't exist?
JS: Yeah, their job is to assess the literature and whatever went into it. So, you know, I think they have to refer to these papers. But in assessing them, they might want to reflect on the plausibility or otherwise or evidence that's coming in from other places. For example, the Working Group III model.