Interview with climate scientist Dr Wolfgang Knorr by Professor Jem Bendell, July 2019.
Preamble: In June 2019 I met with Dr Wolfgang Knorr, a climate scientist with Lund University. With his dozens of peer reviewed climate papers generating thousands of citations, it is clear he has spent decades at the heart of the climate science profession. He wanted to talk about my work on Deep Adaptation, to help me understand more about how the climate science profession had been letting us down. He wanted to work out what he and other scientists like him could do now, given that real time measurements of global heating and the impacts on nature and society are so shocking. Over the coming weeks we met and corresponded. What follows is an edited version of our conversations and correspondence. It is a detailed discussion of the science and the scientific profession. As a Q&A, it is not referenced, but some of the arguments that Dr Knorr mentions can be explored via a compendium of research papers from July 2019 to July 2020. I share the discussion here to encourage climate scientists, food security specialists and other scholars with grave concerns about our predicament, to speak out.
Professor Jem Bendell (me): Thank you for talking and corresponding with me about your views on the climate emergency facing humanity and the role of the climate science profession. First, could you recap a little about your work?
Dr Wolfgang Knorr: I have been a climate scientist for decades. After my PhD from Max Plank Institute for Meteorology, I have worked on climate research projects with a number of Universities. I was Deputy Leader of a major NERC climate research project at the University of Bristol, and now work with the University of Lund in Sweden.
Prof Bendell (me): Earlier in this 2019 European summer there was a record heat wave in France, with temperatures close to 46C in a village near Montpellier. In Germany, the 2015 record of 40.3C was broken on 25 July with 40.9C. This new record only lasted for one day and was topped by 42.6C very far north, near the Dutch boarder. The UK also broke its own record for the highest ever temperature recorded. Even Greenland is experiencing a temperature of 25C in its tundra. Are we seeing climate change in action?
Dr Knorr: What we often hear is that increased levels of greenhouse gases will make such extreme heat events more likely, but that a direct link cannot be proven. In my view, this level of precaution is unfounded. Climate research has so far relied mainly on so-called fingerprint methods, where spatial patterns of climate change from models are compared to simulations. Increases in the occurrence of extreme heat events are difficult to use in this way, because climate models are not designed to accurately simulate extreme weather events. Therefore, climate scientists will often shy away from making bold claims. However, I believe that ordinary people are usually good at sensing when something changes, and will know intuitively that a clustering of such extreme heat events all in the recent past is not normal. This type of informal analysis is not in principle different to applying statistics, which will need underlying assumptions that are equally based on intuition. I would therefore answer your question with a clear YES, we do see climate change in action, and it is very clearly in the direction of a global-scale warming, as we would expect from the greenhouse effect. We don’t even need climate models to make this statement.
Me: Thank you. When climatologists tell me that weather is not climate, I reply that weather is not climate until it is. The distinction is based on how we choose to interpret the latest weather data. My reading has been that these recent increases in temperatures are beyond what the esteemed Intergovernmental Panel on Climate Change (IPCC) expected based on climate model simulations. Do you agree?
Dr Knorr: First of all, there is a vast spread among the results of different climate models. Also, there is no consensus on which models are more reliable, nor on the criteria that could be used to establish a ranking of such kind. It is therefore difficult to state what the models say, and therefore also difficult to make a comparison. But we can say that the currently observed warming is very much consistent with our understanding of the climate system, which goes back to the end of the 19th century. Back then, a Swedish physicist, named Svant Arrhenius, already calculated the expected degree of warming without the use of computer models, and his estimate is still very much in line with our current understanding.
Me: So the confidence placed in the models was not helpful. The new models are producing much scarier projections on temperature increase. That means the IPCC won’t be able to give politicians any easy ways out anymore. What do you think about the political response to climate?
Dr Knorr: I think that this is the key question because in some way it turns around the burden of proof, compared to the question that has dominated discussions so far – whether climate change is a problem, and if yes, how dangerous it is. What we should really ask is: has there been any discernible impact of climate policy on emission rates of greenhouse gases? The only times when there was a moderate dip on the growth rate of emissions was after the collapse of the Soviet Block, and after the 2008 financial crisis. In particular, the slow-down after the financial crisis only lasted for a few years. With moderate I mean that these changes on a global level – and the global emission rate is what counts – are very small compared to what is needed to stop the rise of greenhouse gas levels. However difficult climate diplomacy might be, we should not shy away from clearly stating that nothing has been achieved as long as we cannot see an effect on global measurements. Therefore, the political response has been inadequate.
Me: Drawing on the IPCC, some people are stating that we only have 11 years to avert catastrophic climate change. Others are saying we only have 18 months. These are not my views, but I they are typically referenced by activists and others. How long do you think we have?
Dr Knorr: The problem is that there is no “we”. There is no central global authority that would represent “us”, nor a global democratic decision-making process. There are billions of individuals organized in millions of groups and social networks making decisions about their lives and those of their loved ones on a daily basis. So the question really splits into two: how likely is it that measures will be taken that could drastically reduce greenhouse gas emissions – by someone; and could these measures come in time to avert a climate catastrophe. The answer to the first is “very unlikely”, given the complete absence of any discernible impact of climate policy on emissions. The answer to the second is: even if the impossible was made possible, the scientific data points to the fact that some catastrophic climate change is inevitable. We have already altered the climate system to a degree that is unprecedented for the last 100s of thousands of years, and the more susceptible parts of the climate system will very likely be affected, with consequences that will be catastrophic.
Me: In what area of climate change are you most certain that there will be catastrophic consequences?
Dr Knorr: Before the last ice age, during the so-called Eemian warm period, the northern hemisphere was warmer than during pre-industrial times, or about as warm as now. However, this warming was not caused by a rapid increase of greenhouse gasses, but by very subtle shifts in the way the Earth moves around the sun, and how it is tilted towards it. As consequence, the warming was not global as today. For example, it is believed that Antarctica was slightly colder than under pre-industrial conditions. However, sea levels were about 7 metres higher than today. It is now starting to filter through that this sea level rise might be due to the disappearance of the West Antarctic ice sheet. We already know that processes are underway that are de-stabilizing that ice sheet, but if the results about the Eemian disappearance are confirmed, it will mean that the ice sheet is extremely vulnerable to much more subtle climate fluctuations than the ones that we have already created. We already know that the Antarctic seas are already experiencing increased freshwater influx. And we understand in principle why the West Antarctic ice shield is vulnerable: it is grounded below sea level, so very vulnerable to ocean warming. All taken together, I think it would be quite ridiculous to think that the ice shield will survive. It is just a question of timing, and since the processes that can lead to its collapse are highly non-linear, we are in for some surprises on how fast this can happen.
Me: Why would 7 metre sea level rise necessarily be dangerous, if it happened very slowly?
Dr Knorr: The Breakthrough Institute, based in Melbourne, Australia, has come up with a series of reports, some of which provide quite detailed answers to this question. The amount of people or prime agricultural land situated within one metre of sea level is astounding. And even a slow rise within 1000 years would be still too fast for permanent sea walls to provide long-term protection. I don’t think this only applies for poor countries like Bangladesh, but also for China, the Netherlands, parts of the US and others. The number of people displaced would be so massive that the entire world order based so much on state institutions and quasi-permanent, often impenetrable borders will lose its meaning.
Me: In some of my own work, I have focused on nearer term implications for people from rapid climate change. In particular, I have looked at the impacts on agriculture, and how vulnerable our societies because of that. The UN’s Food and Agriculture Organisation (FAO) already report that globally hunger has been rising these past three years due to climate change. Do you think that people in the richer regions of the world will also experience food shortages or even hunger because of climate change?
Dr Knorr: One thing we need to keep in mind is that agriculture was not this sudden ingenious human invention that it is often portrayed as, but a direct consequence of the on-set of a stable Holocene climate. Before, it was simply not possible because the melting ice sheets led to frequent and very large climate fluctuations. Now, we again have a situation where the so-called biosphere – sea ice, glaciers and ice sheets – are being destabilized. Currently, rich countries with their highly mechanised, fossil-fuel intensive agriculture produce so much food, they can afford to turn a significant proportion into fuel or use it as feedstock. But food production has increasingly become globally integrated, with major exporting regions supplying large parts of the globe. And we expect climate change to lead to longer drought conditions followed by more extreme rain events, and also to make some dry regions drier and wet regions wetter. Many exporting regions for wheat production, for example, are situated in rather dry climates, such as the north American plains, Argentina, Ukraine, or Australia. So yes, I think we could see major disruptions to the global food system. It is difficult to say when and where, because I would not trust regional climate predictions, but in general the possibility is there. And we also need to take into account that we have a very unfair distribution system for food, so if that is not changed radically, very many people could suffer. We cannot even be sure that biofuel programmes will be stopped when there are food shortages. We do not have modelling studies that point to such a drastic outcome. But these studies necessarily rely on a combination of past observed weather fluctuations and model predictions, which will clearly tend to under-estimate the problem. This is being stated very clearly in a recent report by the US-UK Task Force on Extreme Weather and Global Food System. There is some research that shows that already now, weather extremes have increased more than what we expected from modelling results. Mathematically speaking, the climate system has far more degrees of freedom than the models, which means that reality has a vast scope for surprises. And the likelihood that these unexpected changes will make the climate system more rather than less stable is practically zero. Coming back to the initial point, it is stability that agriculture needs.
Me: I have not heard the mainstream climate science profession warning people in the West about the future of their daily bread. Do you think the IPCC reports tend to play down the risks of climate change?
Dr Knorr: It is not difficult to imagine why that should be so. They IPCC is after all an international agreement, and it answers to the interests of the governments of the countries it has signed up to, and it works largely by consensus. So special interests by fossil-fuel emitting countries can have a large impact. But I think there is a more fundamental problem, one that affects much of the larger science community and has to do with framing of the problem. When there is danger you have to confront, you go through essentially two stages. During the first, you need to establish that there really is a problem. During this stage, more uncertainty will lead to less perception of the problem, and less action. But once the existence of the problem has been firmly established in principle, the perspective changes. Now, you need to develop a risk coping strategy, and the less you know about the problem that can be used to assess level of risk, the more concerned you should be. In the first situation, we tend to avoid over-stating because we want to be sure the problem exists, during the second however, the normal reaction is to err on the side of caution. I believe that the IPCC is still stuck in phase 1 while we are now very clearly seeing climate change in action.
Me: I see, so the “precautionary principle” of avoiding hazards that are so dangerous to us wasn’t really being followed, as uncertainty was a cause for conservativism. But could you give an example?
Dr Knorr: Yes. For instance, a major IPCC report excluded the effect of land-based ice sheet melting in its forecasts of sea level rise. This happened despite the fact that the vulnerability of the West Antarctic ice sheet was already known. But lack of knowledge lead to a warped application of the precautionary principle: precaution against making too bold a claim and being discredited in the eyes of the scientific community, and not precaution against failing to identify a fatal risk.
Me: Is the scientific community doing enough to tackle the problem of climate change?
Dr Knorr: In general, I believe that research in the natural science is there to further understanding of the natural world. Scientists should be able to follow their natural instincts, their curiosity and the thirst for knowledge. There is plenty of excellent research going in this direction that has to do with climate change. However, there is of course also room for more directed research that is aimed at tackling specific problems in the interest of society and humankind. In the case of climate change, I think there is massive problem here, because the biggest interest of humankind should be in the highest risks, even if the probability of this happening is relatively low. The research I’ve seen dealing with probability – for example of the probability of not meeting the Paris Agreement’s 2 or 1.5C warming target, was dealing with values in the range of 30%, 50% and such like. But when you want to avoid a fatal risk, then you wouldn’t even accept a 1% risk. The framing of the climate change problem by funding bodies and the scientific community is therefore fundamentally flawed, in my opinion. Instead of studying the possible impacts of 2C warming, we should study the impact of 4C and higher warming events.
Me: Is the aim of the Paris Accord to stabilize the climate with less than 2 degrees of warming being taken seriously by the scientific community?
Dr Knorr: I do not know, to be honest, but I get the feeling that no scientist really believes that this is possible. You do not need to be a climate scientist to work out that there is absolutely no indication of any movement in the direction of the emission reduction at the scale needed. And that is something most climate scientists will have realized, simply because they deal with the subject on a daily basis so cannot avoid asking themselves this question. The only thing that I can imagine will have a major impact on emissions is the rapid and massive deployment of renewable energies, in particular solar energy. However, as long as it is profitable to extract fossil fuels, it will happen. I recently read that coal use has lately gone up again, after a longer decline. That is highly alarming.
Me: Are you worried?
Dr Knorr: I must admit that I am mostly worried for my children and their own children and grand-children if they one day choose to become parents themselves. This is absolutely my personal view, and might be to some degree the result of professional denial. My gut feeling says that it will take another 20-30 years until we see really massive impacts, but that these impacts will look very different from what we expect. The problem is that the image we have right now is so much influenced by modelling studies, at least in the scientific community. But with these climate and other simulation models it is just like the way it is with artificial intelligence. These are mere algorithms that lack any real understanding. The understanding is the work that needs to be done by the scientist. So what I worry about is that too much reliance on established scientific methods has led to a lack of imagination, and that there will be things that we have not considered. Last year, almost the entire Greek olive harvest was unfit for human consumption. The reason: it was unusually wet, just the opposite of the trend we expect from modelling, and that led to the spread of certain diseases that could thrive in the increased humidity. I am planning to initiate a project to look into this, with the hope that confronting the IPCC-based image of climate change impacts with in-depth analysis of how climate change is playing out in the real world right now. There will be thousands of other subtle effects playing out in ways we won’t understand. This is what makes me worried most.
Me: Why aren’t more scientists speaking out about it being too late to stop the disaster spreading?
Dr Knorr: There are actually quite a few scientists who are warning about an impending catastrophe, but you are right, they all stop short of saying publicly that it is too late. What they tend to say is that things are getting worse, there are feedback loops and tipping points and if we don’t do anything radical soon, then it might be too late. It always goes like this: there is problem X and it is urgent and we only have Y years to do implement some radical changes. And then nothing specific about these measures and how they might affect our daily lives. The issue I always had with this is the use of the word “we”. I believe it has actually been “too late” from the start of industrialization. Looking back at history, there is no evidence that our current prevailing technology-based civilization has any way of stopping progression towards some kind of environmental crash. There is no collective mechanism to do that. There are many people who believe that technology will save us, but what I see is that in the face of danger, exaggerated belief in what technology can deliver only increases. To see that our way of life, the way we grew up and we see our children grow up is doomed, is probably too painful to fully realize. And it is also painful to me, which you can see in the use of words here, “probably” and “fully”, qualifiers to create some distance between the thought and myself. What I tend to believe is that there will be another 30 years or so until we will fully experience and thus realize the scale of climate change will do to us. But I might be wrong. Some people believe that the crisis in Syria is the direct result of climate change, a persistent drought that has brought destabilization of an ancient society. Climate change might already play out in this kind of way, with humanitarian disasters where we don’t even see that they are caused by climate change. The next crisis of this kind might happen very soon and somewhere unexpected. Yes, I am reluctant to say this publicly because I don’t want to sound like a Cassandra, a doomsayer. So the problem of not speaking out, of not warning the public sufficiently might have to do with social pressure. With not wanting to be perceived as an outlier.
Me: While it may be awkward to say it publicly, it seems to me that the climate science profession has been letting down humanity. How do you feel about that? And what could scientists in your position do now?
Dr Knorr: Individually I think many of us have been very dedicated. But collectively we didn’t do what was needed. In that sense, the whole climate science profession has let down humanity. I am still working out what that means from now on. I am talking to you and to activists to explore what next for myself and my profession.
Me: Given that I work on an agenda I call “deep adaptation” I am wondering what you see as the implications of your views for adaptation in general and preparing for a breakdown in our way of life?
Dr Knorr: I believe that adaptation really needs to start inside ourselves, with the realization that defence against pain is normal. I can see a lot of defensive mechanisms when it comes to climate change. Not only with the usual climate change deniers, many of whom simply feel an existential threat their way of life – and blame it on those who demand change, not climate change itself. I can also see it with the climate science community. One is a reluctance to admit that it is too late to control climate change, that there is no-one with political power who is really taking the problem seriously and suggesting in earnest measures who can make a real difference. And in the political realm, with politicians being supportive of the latest climate protesters, passing legislation to decarbonize the UK by 2050, but coming up with no specific measures except maybe the idea of phasing out petrol and diesel cars. If find that ridiculous. Once you get used to the idea of denial and defence, the public discourse in large parts looks like comedy. So the answer is – realize your own denial mode, get out of it, realize all the forces that will probably radically change the way most of us live in the coming years – rising inequality, surveillance, authoritarian regimes, media addiction, junk food, and a destabilized climate that will first-of-all create uncertainty. Then prepare to live in an age of uncertainty, remind yourself that our ancestors did just that, and find a new, deeper meaning in life.
Me: What do you think scientists could learn from activists like Extinction Rebellion? In what ways might you and they get involved?
Dr Knorr: Until very recently I thought that no-one, really no-one is taking the problem of climate change serious. There are such endless high-risk – maybe low-probability, but we don’t know – impacts, the problem needs a response of colossal proportions. With the new generation of climate protesters, like Extinction Rebellion, that has changed. What I have realized only recently is that there is nothing much you can do at the individual, personal level, like saving energy, flying less and so on. The machinery of industrialized society will always make sure your efforts are in vain. What is needed is action at the political and decision-making level. This is something I have learned from these activists. I am not an activist by nature, so I am reluctant to make that step, but I believe it is necessary. My impression is that this attitude that I describe for myself here is quite common among scientists. What is happening now is that Extinction Rebellion and similar protest movements increasingly seize the public discourse on climate change and leave much of the scientific community behind, in particular the IPCC. And that is good thing, because we need to move on from the current paradigm. This should answer your second question – moving the public discourse from problem identification mode to problem confrontation mode. We need a sober, grown-up look at all the risks climate change entails. No doomsaying, no preaching, no exaggeration in order to convince others, but also no shying away from speaking out things that are painful. And to find that middle ground is exactly what a collaboration between climate scientists and the new protest movement could achieve.
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