The Carbon Brief Interview: Prof Stephen Belcher

Thursday, 26 April 2018

Prof Stephen Belcher was appointed the chief scientist at the Met Office in December 2016. In 2012, he joined the Met Office as director of the Met Office Hadley Centre. Previously, he was the head of the School of Mathematical and Physical Sciences at the University of Reading. He has published more than 100 papers on the fluid dynamics of atmospheric and oceanic turbulence.

Belcher on how the UK media covers climate change: “I think that the media are certainly covering weather events in a very complete way…On the climate side, I think my experience has been that, again, it’s an extreme weather event that provokes interest in climate and climate change.”
On the UK’s new climate projections, UKCP18, due out later this year: “We think that the projections of the changes to…intense rainfalls with thunderstorms, particularly in the summer, will be different and interesting and more faithful.”
On the impact of Brexit on climate science in the UK: “A question over Brexit will be whether UK scientists continue to have access to those pan-European projects. And I sincerely hope that we do, because I think we get a lot out of them…An additional potential effect of Brexit is on the enthusiasm of staff to move, scientists to move across Europe and into the UK. Twenty percent of the scientists in the Met Office are from overseas.”
On when he first heard about climate change: “It was certainly being talked about when I was an undergraduate in the mid-1980s.”
On explaining climate change to children: “Most children I meet know about climate change and I think it’s taught at quite a junior level at school now. And, clearly, there are the iconic impacts like the sea-level rise, the Amazon rainforest and Arctic sea-ice as obvious examples where we’ve measured change and we can see it happening in front of us.”
On what the Paris Agreement means for climate science: “Since Paris, now there’s much more focus, I think, on precision…There’s requirement for climate science to project at a degree of accuracy that I don’t think we had before…The precision required [for carbon budgets] is at a whole different level of magnitude now.”
On the climate-science questions he would like to see answered: “Around the carbon budgets, a question that I would like to see more clarity on is whether land-based vegetation will continue to absorb carbon dioxide at the rate it currently is, or whether in a future climate, that drawdown of carbon by plants on land will change…I think the second would be understanding better the role of the oceans in the climate system.”

On the uncertainty over climate sensitivity: “I take a rather pragmatic approach. It’s an uncertainty at the moment we have to live with, so within that uncertainty what can we say? And let’s not forget the climate sensitivity is a global measure. What we really care about is regional expression of climate change.”
On the IPCC’s sixth assessment report: “It looks like that will have more of a focus on risk and it looks like it is responding to Paris agenda. So that’s a very positive step.”
On potential topics for future IPCC special reports: “Carbon budgets…are clearly absolutely pivotal. So something that could bring, perhaps, that work together with something that could cut across the three chapters [IPCC working groups]…I think the cities…is an interesting one, too, actually.”
On the IPCC special report on 1.5C due out in October: “I hope it will be used in a productive way that recognises that 1.5C is an extremely challenging target, but it’s not beyond reach and there are a range of pathways to it.”
On negative emissions: “Negative emissions is untested. So it would clearly require a huge engineering effort and, indeed, social science effort to really put them into place.”
On scientists researching geoengineering: “The use of geoengineering…is an area where climate science is beginning to get into and I think that’s probably a good thing. And the role of climate science is to engage in that kind of debate.”
On why he chooses not to answer energy policy-related questions: “I think if we did start speculating about policy we would be straying way beyond our area of expertise and that wouldn’t be helpful.”
On the “red team/blue team” proposal to interrogate climate science, as supported by Scott Pruitt in the US: “Peer review…seems to me to be a highly appropriate way of challenging science. It avoids personality overwhelming scientific line-of-reasoning and argument.”
On why the Met Office publishes probabilistic seasonal forecasts: “We have some skill for winter temperatures now in the UK and this is a development we made just a few years ago. So planners for the transport sector in the UK [can use the forecasts], if there’s a risk of cold weather.”

Carbon Brief: A question around your new role. Can you just explain what the Met Office chief scientist actually does and what that role is there to do, compared to some of your previous positions?Stephen Belcher: So, the Met Office is the national weather service. We’re here to provide weather forecasts, but we also provide information on climate and climate change. To underpin that, it’s a scientific research programme to improve the forecast to develop more information about climate variability and climate change. My job is to run that programme. It consists of 500 scientists, many of whom are really international experts in their field, particularly on the climate side and some of the weather scientists. So it’s a real privilege to have this job. I guess it’s come about through 20 years of research, weather and climate research in universities, primarily and prior to that in the Hadley Centre itself.CB: And, in your new role, how much new science are you actually doing? Have you still got your hand on the scientific and research side?SB: Yeah, so I do that in a variety of ways, actually. It’s an interesting question because clearly with such a large programme a really interesting part of it is to learn about all the new science that’s going on, because there’s so much of it. Getting your teeth into it is great fun. And then there are some areas where I have particular interests and I participate there. In fact, I do have one or two of my own research projects that I still manage to keep going, in a small way as well, particularly on oceanography.CB: OK. So how much time can you devote to your particular research topic?SB: A modest amount, I would say. I wouldn’t like to quantify it. My primary responsibility is to make sure the staff are receiving the direction that they need and, of course, playing a role as director of the Met Office and doing the outward-facing work, presenting the Met Office’s work, such as this interview. I try and spend half a day a week to a day a week on research. So, in fact, I’m going to the US in a couple of weeks’ time to Santa Barbara to do some research.CB: So there are actually papers being published with your name and that will continue on in your new role?SB: I’m rather keen to continue doing that, yes, so I try and publish four papers a year. And I think I’ve been encouraging the senior management team in science in the Met Office that this is a really important part of our leadership role. To demonstrate that we are still active scientists.CB: You mentioned that you have this new outreach role related to the job, which includes talking to the media and explaining the science that the Met Office produces. How well do you think the UK media covers the topic of climate science and the related topic of weather as well?SB: I think that we often see weather in the news. It’s something of a British disease, isn’t it, of the weather that we suffer? So particularly the snow events that we had were the story of the year so far. So I think that the media are certainly covering weather events in a very complete way. But one of the things that we’re trying to do in Met Office now is supply the science explainer behind that weather event. So, for example, you may have seen around the first snow event which was caused by something called a sudden stratospheric warming. So this is air, high up in the atmosphere, sort of ten to 40 kilometres up. And the circulation, the movement of that air can change quite suddenly, although perversely it’s called a warming. But it changes the motion of that air. And when that happens, that can then move the winds at low levels to make them come from the east, which tends to mean they’re cold and tends to mean when there’s rain it falls as snow. So we had a nice little explainer video on that sudden stratospheric warming that went into some of the physics and I think that’s nice to do.On the climate side, I think my experience has been that, again, it’s an extreme weather event that provokes interest in climate and climate change. “Is this flooding event due to changing climate, or is it just part of our natural weather?” So, again, presenting science in those opportunities, I think, is very important for us to give that climate change perspective on these weather events.CB: How do you think the topic of climate science can be better reported or discussed in the media? It’s become quite a politicised and, in some publications, quite a partisan topic. What role can the Met Office do to try and improve the accuracy and the quality of the discussion around climate change?SB: I think the Met Office has a role to play in providing authoritative, scientific advice. And to provide that in a way which is as accessible as possible to people and, of course, different people react to different stories. But doing that, of course, in partnership with the broader UK academic community. So, for example, we did a Science Media Centre briefing last year on the end of the pause in global mean warming. We had other members from Oxford University on that panel and I think it was a lot better as a result of that.

CB: The Met Office will be launching the next set of climate change projections for the UK, known as UKCP18, later this year. What can we expect from them, and how will they be different to the last round?SB: So UK Climate Projections 18, UKCP18, will be the next generation of climate predictions for the UK. And they’ll be used by a range of researchers and consultants to understand potential impacts of climate change on the UK. The UKCP18, as you say, will replace UKCP09. So it’s a 10-year update. So one of the things that will be improved is the overall modelling that sits behind it has moved on enormously in those 10 years. And the observations that we use as part of the modelling have another 10 years of data, showing more of a climate change signal and, of course, the improved data improves the modelling. So there’s a general quality improvement.In addition to that, we’ve got several new angles and dimensions to the UKCP18 that we didn’t have before. So I think there are two main ones and the first one is that UKCP09 primarily gave evidence about average climate and how that might change, whereas I think the agenda has shifted now. People really want to know what are extreme events going to look like. How is their flavour going to have changed in a future climate? So CP18 will give much more evidence about seasonal climate and the range of possibilities that might encompass. So a headline message from UKCP09 was that summers will become hotter and dryer, but a question we may want to ask is, well, how many of those summers might be really hot and really dry and how many might be rather wet, disappointing summers? Similarly with cold winters, we’ve had a reasonably cold end to the winter this year. Are they going to disappear completely? Well, of course, not. But they’re going to be gradually replaced by more warmer, wetter winters. It’s those kind of changes in the extremes that I think people are looking for. So UKCP18 might have some of that information.The other major technical advance is the way we’re treating rainfall, particular in the summer. So we have a new modelling system, which is the modelling system we use in the Met Office for forecasting local weather on a daily basis. And we’re able to do, for the first time, climate simulations with this very detailed model. And the difference in this model is that it actually represents thunderstorms explicitly, rather than having to represent them in a rather indirect way. So we think that the projections of the changes to those intense rainfalls with thunderstorms, particularly in the summer, will be different and interesting and more faithful.CB: What kind of resolution are we talking? Is it across a county level, a city level? In terms of kilometres, what kind of resolution?SB: So, these fine-scale simulations will be a two-kilometre resolution, so if we contrast that with the 12 kilometre or 20 kilometre that previous generations had, this is quite a big advance. And it’s not just the rainfall that’s captured better here, it’s also the catchment, the river catchments that collect the rainfall and direct those into rivers, which is so important for controlling flooding. That’s also captured at that scale. So I think this is a major advance.CB: And we’ve seen a recent paper – yesterday, in fact – a couple of papers, talking about how there’s been a weakening of AMOC over the past 50 years, or 100 years or so, and that could potentially have great impact on the UK. So how do these new projections deal with something like that? Or is that too new, in a way, for it to be incorporated?SB: So, more generally, we try and capture those variations and their effect on the climate in two separate ways. The first is when we’re trying to understand what might happen over the next few years, we can use the variations in the AMOC to initialise simulations and account for that initial state or weakening of that. And that, therefore, represents that impact on the weather. In UKCP18, the way we would treat it is that we run a whole bunch of simulations and they will have AMOCs in different phases at different times, so the spread of possibilities is partly due to the AMOC variability.

CB: The UK is one of the leading centres for climate science in the world. And we’ve got a situation coming in a year or so when the UK’s going to leave the European Union and the European Union has traditionally made up quite a big chunk of science funding more generally, or been a source of science funding. Do you see any risks with Brexit around how climate science is going be funded in the UK?SB: So, it’s true that the UK is really strong at weather and climate science and the whole UK academic community and the Met Office, partly because we use all the same modelling tools, we really punch above our weight. We’re very integrated with the European community, which is also very very strong. Germany, France and Spain and Italy, for example, and the Nordic countries. We participate in pan-European projects. So a question over Brexit will be whether UK scientists continue to have access to those pan-European projects. And I sincerely hope that we do, because I think we get a lot out of them. Another area where we collaborate in Europe, of course, is through the European Centre [for Medium-Range Weather Forecasts] and Brexit won’t affect that. The European Centre is based at Reading and it provides additional forecasting capability and research tools. And that will be unaffected by Brexit. So it’s kind of a mixed bag here.I think the final thing I would say is that climate science is a truly global science and we’ve got collaborators all over the world, including Australia, South America, South-east Asia and there are new funding streams that the government has put in place to actively encourage collaboration with some of these countries. So, that’s actually building additional, new capabilities and partnerships, which is very welcome.

Embedded component (note)CB: It sounds like you feel fairly confident then that Brexit will not disrupt or divert the direction and quality of climate science that you’re producing?SB: Yes, I would certainly hope not. An additional potential effect of Brexit is on the enthusiasm of staff to move, scientists to move across Europe and into the UK. Twenty percent of the scientists in the Met Office are from overseas. And we are trying to offer them every assurance we can that, of course, they’re very welcome and their efforts are very warmly appreciated, both in the UK and the Met Office, specifically.CB: Going back in time a bit, you originally studied mathematics, before going on to complete a PhD in fluid mechanics. Was it always your intention to move into researching meteorology and climate?SB: No. [laughs] I always liked maths when I was at school and still do. As an undergraduate, I did a whole range of mathematical subjects and I always knew I was interested in the use of maths in physics. When I chose to do a PhD, I was very inspired by Julian Hunt, now Lord Hunt of Chesterton, who was director general of the Met Office 25 years ago, who showed that you could use this mathematics and physics to actually understand what’s going on in the real world outside. And I found that very inspiring and I still do now, actually – the idea that we have these equations that describe the physics and it really works outside, and we can really demonstrate that on a daily basis with the weather forecast. And, furthermore, we can confront one of the biggest challenges of humankind at the moment of climate changes and I think is truly inspiring.

CB: What’s your earliest memory of being aware about climate change? Was it a TV show, a book, a lecture? Can you actually remember that moment where, as a child or teenager, the penny dropped and it kind of came into your consciousness?SB: I’m not sure I do have a single moment at this point. It was certainly being talked about when I was an undergraduate in the mid-1980s. So there were various public lectures given and I remember one or two of those [which] talked about the early emergence of climate change as a scientific study area. And then I guess in the early 90s when the Hadley centre was being established and the then prime minister Margaret Thatcher started discussing it as a real issue that needed political confrontation and political action. So, I suppose it was then that I began to see that it was an important area that was really beginning to move, not just into a really important area of scientific endeavour, but had real practical application.

CB: I’m not sure if you have children, but how do you communicate something like climate change, which is a very complicated and multi-faceted issue, to children?SB: [Laughs] I do have one son who’s now 19, so he tends to explain to me, actually. How does one describe it for children? I think it clearly depends on the age of the children. The physics of the greenhouse effect is rather quite straightforward. Sunlight comes in from the sun, passes through the atmosphere and warms the Earth, then the Earth warms and that sends heat back out. If we change what’s in the air, the amount of heat that gets sent out changes and the planet can warm as a result. The way of reaching people is usually through real events, of course, real impact. So, most children I meet know about climate change and I think it’s taught at quite a junior level at school now. And, clearly, there are the iconic impacts like the sea-level rise, the Amazon rainforest and Arctic sea-ice as obvious examples where we’ve measured change and we can see it happening in front of us.CB: What do you think are clearly the biggest unknowns about future climate change? Where are the biggest surprises likely to come from? I guess it’s a question of known knowns and unknown knowns, etc.

SB: Well, I think I would start by thinking about the Paris Agreement, because that’s really changed the agenda for climate science now. Arguably, prior to Paris there were two questions: is the world warming and, if it is warming, is it due to human activities through the burning of fossil fuels? The fifth assessment report of the IPCC absolutely nailed those questions. Warming was unequivocal and it’s extremely likely that, within the last 50 years, it’s due to fossil-fuel burning. And that’s set the evidence base for the Paris Agreement. So, since Paris, now there’s much more focus, I think, on precision. We are roughly 1C above pre-industrial now. So with an ambition to stay below 2C, if not the more challenging target of 1.5C. That’s quite a small margin. So, there’s requirement for climate science to project at a degree of accuracy that I don’t think we had before.So that’s one major challenge. The second is carbon budget. Again, the precision required is at a whole different level of magnitude now. So, again, two parts to that. One is what scenarios might keep us below those levels. But the area where the Met Office really contributes is, given emissions of carbon dioxide into the atmosphere, how much stays in the atmosphere and leads to warming? At the moment, there’s really quite a lot of uncertainty around that. So we recently published some work looking at some previously unrepresented effects, like thawing of permafrosts, methane from the wetlands, aerosol interactions. And they all tend to reduce the amount of carbon we can release to keep us below the 1.5C target. So I think that’s the second area of massive requirement.And then the third is, we know we’re committed to a change in climate over the next 30 or so years, the question is what will the character of the weather events we experience in that time, how will that character change? So we know we get heatwaves now, we know we get flooding events, but will they become more frequent, or will they become less frequent, but more intense? What’s the character of those events going be like and how will those hazards translate into real risks? So when it rains, what does that mean for flooding defences in the UK? When there is a drought, what does that mean for what kind of crops we might be able to grow in South-east Asia etc? So that whole risk way of thinking around extreme events, I think, again, brings a new set of challenges to climate science that we didn’t really confront before.

Embedded component (note)CB: You mentioned permafrost melt. Do you feel that some of the sometimes discussed positive feedback loops that Tim Lenton and others have researched and written about, do you think those are incorporated and discussed enough into some of this modelling and scenario work?SB: Well, the climate system is the epitome of a complex system. And so our models of the kind of the climate system are inevitably incomplete. And there’s inevitably discussion about things that are just out of reach of the current generation of models. And that’s one of the things that drives the science forward. So, the short answer to your question is, we, of course, need to do more about these processes and that will then unlock a set of processes beyond which we then can consider. In a way, that’s what’s the fun of the subject, or the challenge of the subject.

CB: Maybe coming at the question from a slightly different angle. What are the climate science questions you would like to see answered most, more than others?SB: Gosh, it’s a matter of picking the few that are tractable. So I think, around the carbon budgets, a question that I would like to see more clarity on is whether land-based vegetation will continue to absorb carbon dioxide at the rate it currently is, or whether in a future climate, that drawdown of carbon by plants on land will change. At the moment, there’s enormous uncertainty across the different models and the different world centres give different answers. But there’s some really ingenious work going on to see if we can try and unpick this. So that would be one.I think the second would be understanding better the role of the oceans in the climate system, particularly, it’s contributions to the slowdown in global mean temperature rise in early part of the 21st century. But also in driving climate variability. You mentioned the slowing down of the AMOC. We don’t really have good ways of representing that in our models, so there’s quite a way to go. The observations of the oceans are relatively new and they’re relatively shallow still, so I think, again, the time’s right to really make progress there.And then the final one is around the weather systems that I just talked about, how they might change. I think, again, we’re poised with this new technology to really make some strong advances in rainfall changes under a changing climate. It’s been a thorny issue for us for a long time, again, the divergence of the results from the different international centres and it feels like we’re really at a time when we could make progress on that.CB: The tightening of the reins of uncertainty around climate sensitivity is often hailed as one of the priorities for climate science. Where do you stand on this particular issue?

SB: Where do I stand on this? So climate sensitivity is an emerging property of a modelling system and there are a variety of ways of estimating it. The range is proven persistently stubborn to narrowing it. I think we’re beginning to understand, perhaps, the reason behind that better. So we’re beginning to understand the range better and the role of cloud processes, on the one hand, in the deep modelling systems, the role of observation uncertainties of some of the other methods for estimating it.There is also an interesting new strand of work thinking about storylines. Are there physical constraints on the range of climate sensitivity? So that offers some hope and I think there’ll be work published later on this year that might shed light on that. I take a rather pragmatic approach. It’s an uncertainty at the moment we have to live with, so within that uncertainty what can we say? And let’s not forget the climate sensitivity is a global measure. What we really care about is regional expression of climate change. So narrowing that uncertainty, I think, is an area where I would put more focus. The global uncertainty is one thing, but the regional, of course, is important.CB: If, given all you know, you were asked to put your finger on a certain value, would it be 2C, lower than 2C, higher than 3C, where’s your experience and knowledge telling you that it’s most likely to be?SB: The expert judgement in the IPCC really is a definitive statement on this, because that draws together multiple lines of evidence and a range of experts. And the 1.5-4.5C comes from that as the most likely. But, of course, there’s a broader range that could be possible. There’s a 10% chance of it being more than 6C, for example. So it will be very interesting to see how the generation of models that are currently being used, and what will contribute to the sixth coupled-model inter-comparison project, the CMIP6, that’ll be a really interesting aspect.CB: You think that will help to narrow the uncertainty?SB: Well, whether it narrows the uncertainty, or whether it does not, remains to be seen. It may increase the uncertainty, we don’t know yet.

CB: Moving onto the IPCC, what are your thoughts on the IPCC’s big assessment reports. We’ve had AR5 in 2013/14, we are due AR6 in 2020/21. Is this the best model? Is this the best way to be effective in terms of bringing together the latest state of our knowledge around climate science? Or is there possibly a better option? And what would you like to see the IPCC do more of, or, perhaps, less of in the future?SB: So, the assessment reports that the IPCC produce have become, I think, a touchstone for how a scientific consensus can be drawn on a topic. So, in that sense, they’ve been enormously successful. And then, of course, providing the bedrock of scientific evidence that underpins Paris has been a massive success. It is a huge amount of work and the Met Office contributes much staff time to the IPCC assessments. It’s something as scientists that we at the Met Office get a huge amount of pleasure and pride from contributing to that. The sixth assessment, it looks like that will have more of a focus on risk and it looks like it is responding to Paris agenda. So that’s a very positive step. I think the other thing I’m really pleased to see is the IPCC looking to produce interim reports on focused topics. So later this year we’ll be seeing a 1.5C report and, whilst it’s been a rather gathering of evidence, it’s clearly a very important topic. So I really welcome those shorter, but more focused topics.

CB: On the issue of topics, there’s one after the 1.5C report on land. And there’s another sort of ocean-focused one and there’s even been talk in the next assessment cycle of there being one focused on cities, for example. What are some of the topics you would really like other than those? What do you think are really key candidates for being a special focus?SB: Carbon budgets, as we’ve discussed, are clearly absolutely pivotal. So something that could bring, perhaps, that work together with something that could cut across the three chapters [IPCC working groups]], I think that’s the secret to the use of these interim reports, which carbon budgets clearly does, by looking at, for example, vegetation processes and how they draw down CO2, some of the mitigation in working group 3 can clearly inform the rate at which technology can reduce emissions, etc, etc. So that would be one.I think the cities one is an interesting one, too, actually. Cities, of course, are where most of us live, an increasing number. Many cities are on coast lines so are vulnerable to raising sea-level. So the whole adaptation agenda, cities are really hot spots for that. But, of course, cities are also places where much of our emissions take place, so it feels like there’s an opportunity to design cities in a climate-smart way. I know there’s a community of planners and engineers who are already thinking that way, so, perhaps, trying to bring that into the IPCC in a creative way could be important. So thinking about that from a “What can we do, we’ve described the problem but what are potential ideas to mitigate the problem and solve the problem through adaptation?” I think that’s an exciting opportunity.

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CB: Back to the 1.5C report due out later this year. What are your hopes and expectations of that report in terms of what it will contain and also how it will be consumed?SB: In terms of what it contains, it can only contain the literature that’s out there. These reports are just assessments of existing literature, so I am looking forward to seeing a survey, a brief and succinct summary of that literature. I hope it will be used in a productive way that recognises that 1.5C is an extremely challenging target, but it’s not beyond reach and there are a range of pathways to it. For example, remaining under 1.5C permanently, or potentially overshooting to higher temperatures and relaxing back down. So some constructive debate about those possibilities and the achievability of those possibilities I think would be a great outcome. As ever with the IPCC, it will identify gaps in our knowledge and that will stimulate new scientific research. In terms of an organisation like the Met Office that would be very exciting for us to participate in filling those gaps in the knowledge.CB: It’s interesting that you just said that 1.5C was not beyond reach, whereas some climate scientists are pretty much on the record, saying: “1.5C has gone, it’s going to be challenge enough to stay below 2C.” So, you do think it’s possible to stay below 1.5C?SB: I say what I say because there are some scenarios which have been created that do keep us below 1.5C. They are extremely challenging to implement…CB: But they also, predominantly, or all of them rely heavily on negative emissions.SB: Yes, they do.

CB: So what’s your view on the issue of negative emissions? Because it is a topic that’s kind of reared up after the Paris Agreement, where suddenly we have this focus on 1.5C, and we now realise, once we’ve looked under the bonnet of these models, that most of them do heavily rely, even the 2C ones, on negative emissions.SB: Yes, so the scenarios that keep us below 2C, and certainly the ones that keep us below 1.5C, are extremely challenging scenarios. Negative emissions make up a large part of those scenarios. Negative emissions is untested. So it would clearly require a huge engineering effort and, indeed, social science effort to really put them into place. I think, as a climate scientist, my role and the role of the Met Office is to explore the implications of those scenarios and help measure the benefits and the costs of those scenarios with the folk who developed the scenarios and the people that might want to implement them.

CB: On a related topic, as I guess you could argue that negative emissions are a form of geoengineering. On the other side, not the carbon dioxide removal side, we’ve got the solar radiation management side which, arguably, historically has been a more controversial area. What are your views on that because that’s another topic that seems to be fast moving and there seems to be more and more chatter and talk and discussion around it. I think there’s even some kind of experiments planned later this year around this in the US. So where do you currently stand on solar radiation management, in terms of the research side of it and then, separately, the potential deployment of it?SB: So the role of the Met Office is to provide scientific advice. So, for example, we have begun to think about the potential for solar radiation to limit warming beyond an overshoot scenario. But that comes with a cost and it comes with a benefit. So it’s trying to assess these costs and benefits – and the costs may come to water availability in certain areas of the world and the benefit may be come to less temperature rise in other parts. So thinking about these scenarios, for example, the use of geoengineering in that context, is an area where climate science is beginning to get into and I think that’s probably a good thing. And the role of climate science is to engage in that kind of debate. And, having provided the evidence, of course, it’s for our policymakers to decide how to use that evidence and advice.CB: On the issue of politics, the UK, amongst most of the other countries in the world, has signed up for Paris. Do you think there are any policies that we’re missing, or tricks that we could be deploying, in terms of how we in the UK meet our Paris obligations and also our Climate Change Act obligations, which may or may not be retuned slightly at a point in the future to make it more compatible to the well-below 2C demands of the Paris Agreement? So are there any policies that we’re not deploying, or technologies, etc, we’re not doing in the UK, that we should be doing to help us meet those obligations?SB: So the role of the Met Office is to provide advice on the scientific evidence. So we provide that advice, for example, through to the Climate Change Committee, which helps set the carbon budgets for the UK. The advice that we provide is on how the climate might change and the impact of those changes, for example, through the UKCP18. It’s then for parliament and the officials in Whitehall to determine how to use that advice and convert that into policies.

CB: So you can’t, or you won’t have a view on, say, CCS [carbon capture and storage], or nuclear, or solar, or combined heat plants, or all the huge shopping list of options that people have?SB: As a scientist, I have to stick to what I have expertise in and, of course, the Met Office has to do the same. That it’s role in the world. I think if we did start speculating about policy we would be straying way beyond our area of expertise and that wouldn’t be helpful.CB: You mentioned the CCC and the fact the current Climate Change Act requirements of 80% reductions by 2050. That’s currently not Paris compatible. I think that was designed 10 or more years ago to be for 2C. And, obviously, Paris is “well below” 2C. How much ratcheting-up, in your scientific opinion, would you need to go beyond the “80% by 2050” to make sure it’s compatible with the carbon budgets etc and the UK’s contribution to that?SB: The UK through the Climate Change Committee has had a fairly ambitious agenda on carbon reduction. The second point to make, perhaps, is that if we want to stabilise climate at any level we need net-zero emissions. So, as a global community, that’s the target we need to aim for…CB: By when? By what point?SB: That depends on what target we want to reach and when we want to reach that target. And really the role of our science is to help answer that end of the question.CB: So, if the CCC comes to you and asks for your help to help them to make that assessment, you will be an active participant or help them?SB: Yes, absolutely, that’s the core part of our job. In fact, within the Hadley Centre, we led a project called AVOID which Jason Lowe was very involved in, which brought in technologists and policy planners to try and bring some of these strands together. And much of that project did go straight to the Climate Change Committee. So I think that is an important part of our role. But the Met Office core mission is to work on climate science. That’s what we’re there to do and that’s where we have our expertise. Of course, we have parts to play with others to try and get a more complete picture, but we stick to the climate science.CB: When you look across the Atlantic and you see the way that climate science is being politicised across the political divide, but not least by the current president of the United States, in terms of the US – and it has been, historically, a key contributor to the global body of knowledge around climate science – do you have concerns about the way that some of the climate science seems to be under this kind of political pressure at the moment?SB: Well, climate science is in the spotlight because it relates to a challenge for the globe. Each country needs to determine through its democratic process how it’s going to react to the change in climate. As scientists, the most important thing we can do is to retain our integrity and to stick to evidence and present the evidence in a balanced way. So the evidence comes from observations, through theoretical arguments about the greenhouse effect, and through models. And we need to express that evidence and the confidence in that evidence as it build up over time. I think that’s the most important thing that scientists can do. And I think that’s why at the Met Office we try and stick to what we know.CB: But, in the US, you’ve seen in the last year or two attempts by the Trump administration to actually defund, say, key satellites that are being used to collect data on the Earth’s atmosphere etc, or the oceans, as well as defund actual climate science done by NASA and others. If that was successful and Congress carried through and did vote through to strip away core funding of some of that research, could the UK and others around the world, other science communities, pick up the slack and help with that?SB: So the funding of science is, of course, again something that is determined by elected governments. There’s no doubt that there’s huge talent in the US climate science community. And it’s a massive privilege and pleasure to work with them. What we have seen in recent years in the UK is an increased interest in taking our science to overseas development assistance, so into developing countries. So, at the Met Office now, we have a series of international partnerships that we’re growing that takes our climate science to help understand the vulnerabilities in China, Brazil, South Africa, South-east Asia and India, and work with the scientists in those regions to develop climate services that takes that climate science and converts them into services that can help reduce the impact of climate change, or reduce the damage done by natural disasters. So I think we’re seeing in the UK an appreciation that we have great strength in this area, that we can deploy right across the world to help some of the most vulnerable people in the world.

CB: Just on the issue of the US, one proposal that has been put forward – which, depending on which day of the week you look at, it seems to be in favour or not – but one idea put forward by Scott Pruitt, for example, the head of the EPA in the US, is that there should be this red/blue team approach to interrogating climate science. Effectively, it’s having a bunch of scientists who are pro and those who are anti and then they both have to present their best case and then the winner takes all and it’s aired on television. What’s your reaction to that kind of approach to assessing science?SB: I think science is a pretty bruising process. When you do a piece of research, you find something new and you try and convince your peers that you’re right and that you’ve discovered something new and that could imply that something that was previously thought right is wrong. So that is inherently a bruising and rather confrontational process, which happens all the time. So the science that forms our understanding of the climate system and climate change has undergone tremendous challenge from many different angles and continues to do so. And that’s absolutely right. That’s how science progresses. The system at the moment of peer review means that every piece of published research is assessed by anonymous reviewers and the author has to satisfy the editor of the journal that they’ve addressed those challenges. This seems to me to be a highly appropriate way of challenging science. It avoids personality overwhelming scientific line-of-reasoning and argument. And if we want the scientific line-of-reasoning and argument to come through, it seems a robust system to me, the peer-review system that we have now.CB: Is there anything that can be done to improve the peer-review system as it currently works, do you think?SB: Well, so articles and journals are subject to rather robust review. As ideas take ground that’s usually because a body of papers have emerged coming to common conclusions and often through multiple lines of evidence. So, again, science evolved through this consensus of multiple lines of evidence that have each been subject to challenge. So I find it hard to imagine a more robust system than that. And then, in climate, we have the additional layer of the IPCC reports, which take the published reports and synthesise those in this assessment process and the IPCC assessments themselves are subject to review. In fact, anyone can offer comments or criticisms. The review process is completely open. And the authors of the report are obliged to respond to each of those criticisms, one by one. This is tremendously robust and, I’m not sure quite what word to use, but it’s really checked at every point which is entirely appropriate for a subject as important as climate science.CB: OK, the final question. The Met Office does climate forecasts…SB: Yes.CB: It does next-day, or five-day weather forecasts, but it also does longer-term weather forecasts and across seasons.SB: Yes.CB: Which, I think, is a new scientific area, but also quite a challenging area from a communications point of view. People get confused between whether the Met Office is actually predicting or forecasting that it’s going to rain in three months’ time on a certain day, or whatever. Do you want to just explain a little bit about tiptoeing through quite a tricky subject…SB: The subject of these longer range seasonal outlooks is an experimental science still. The skill in this approach differs in different parts of the world and that’s an inherent property of the climate system. So, for example, in areas of the tropics we’re better able to predict particularly when there’s an El Niño or a La Niña, such as we had a few years ago. So this means that these are probabilistic forecasts. We tend to say the temperatures – we split the temperature into three ranges – are higher than average, lower than average and average. And we do that because we think that’s a sensible set of outcomes that we do have some skill in. So whilst it might not help you plan your summer holiday this year, we feel, on expert judgement, that we do have some skill in that and providing it further would not be helpful. The communication challenge is a challenge. Because it’s a probabilistic forecast, we don’t expect to get it right every time. So to assess the skill requires looking over many years and looking at the average, when we get it right, two times out of three or so. We do find some users find this useful information. And, ultimately, the Met Office is about converting its science into services. And there are some users and some elements of government…

CB: Give me an example of someone who finds that useful…SB: Yes, so we have some skill for winter temperatures now in the UK and this is a development we made just a few years ago. So planners for the transport sector in the UK, if there’s a risk of cold weather, the old story of storing up stockpiles of salt, you can plan ahead to that. Airports can think about the number of closures that they might need. So they’re able to balance the risk of it happening versus what they need to do if it doesn’t come off, so they’re able to deal with that…CB: But you’re talking about industries that are making multi-million pound decision-making, whether, say, to prepare an airport for certain types of weather in two or three months time, or salting hundreds of miles or roads, etc. What happens when that doesn’t happen? I know you said it’s probabilistic, but when it doesn’t, do you get push back? I know sometimes there’s been media pushback against this. But do you get from consumers from sectors, saying, “But you said this?”SB: Well, the users, like the transport sectors, look at the costs of action and they look at the benefits of that cost if the forecast is correct versus the loss of that cost if the forecast is not correct and, on balance, it comes out as being a cost-saving exercise to use the information from the forecasts. So it’s that kind of application where I think this emerging science is proving useful.CB: OK, thank you very much for your time.SB: OK, thank you very much.

Article information

The interview was conducted by Leo Hickman at Carbon Brief’s office in London on 12 April 2018.

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