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June, July, and August of this year were the hottest on record for planet Earth. This Fourth of July is reported as likely the warmest day on Earth in some 125,000 years. The second-hottest was July 3. In the United States, more than 6,500 local heat records were shattered this summer. Based on the unprecedented and relentless milestones, earlier this week, the United Nations Secretary General António Guterres declared that “climate breakdown has begun.” 

Scientists have been warning about this possibility for decades. And in recent years, the mounting climate-related disasters—extreme storms, droughts, floods—have pointed toward an accelerating rush into the relative unknown of climate catastrophe. 

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Action as a citizen is far more powerful than action as a consumer.

But Guterres himself is not a climate scientist (though he did study physics and taught systems theory at university). So we wanted to know: What should we make of this ominous proclamation?  

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We called up Luke Kemp, who is a research affiliate at the Center for the Study of Existential Risk at the University of Cambridge and currently a visiting faculty fellow at the Notre Dame Institute for Advanced Studies. 

Kemp lives in the intellectual world of the unlikely-but-calamitous. While most people are fretting over a change in storm surges along the Eastern Seaboard, he is swimming around in a not-too-distant possible future where the East Coast begins miles farther west. 

The scientific community has focused attention on limiting warming to 1.5 to 2 degrees Celsius above preindustrial levels, aiming to avert too much disruption to civilization as we know it. But we are most likely to see warming of at least 2.7 degrees—and possibly up to 8.6 degrees—by 2100. (It’s worth noting that, save for a dip during the first year of the COVID-19 pandemic, global emissions are still climbing annually.) Kemp argues that scientists have done a terrible job considering and communicating what these more severe outcomes would mean for us, as a species. 

“Prudent risk management requires consideration of bad-to-worst-case scenarios,” he and his colleagues wrote in a PNAS paper last year. “There are ample reasons to suspect that climate change could result in a global catastrophe,” they wrote. But “at present, this is a dangerously underexplored topic.” Research has found, for example, at a 6- to 9-degrees Celsius warming (well within the realm of possibility in the next 75 years), the East Antarctic ice sheet would be doomed, possibly sending sea levels up more than 130 feet. At even just 2 degrees warming, the West Antarctic ice sheet will likely begin an irreversible demise, eventually raising sea levels by 10 feet—even if the warming trend was quickly reversed. 

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And these risks, he and his colleagues argue, are not singular, but are likely to compound and interact with one another. It wouldn’t just be a rise in sea levels, but also simultaneous economic crises, political conflict, famine, and mass illness. 

Kemp explains what’s in a word like “breakdown,” how we can turn overwhelming complexity into stark simplicity, why he doesn’t really care if his students leave the lights on, what we can learn from the Bronze Age, and why people should keep inviting him to parties. 

In Body Image
NO OSTRICH: While most of the scientific community zeros in on the implications of a small amount of warming for the planet—an absolute best-case scenario—Luke Kemp advocates for a deep exploration of what will happen with substantially higher amounts of warming. Photo courtesy of the University of Cambridge.

When the United Nations Secretary General António Guterres used the term “climate breakdown,” it sounded like a pretty serious proclamation. As someone who thinks a lot about these things, what does that phrasing mean to you? 

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“Breakdown” has never had an official consensus definition. What it means varies by the person. These are, of course, very concerning and dramatic proclamations. But scientifically, they don’t mean much by themselves. 

To me, it means that there is a threat of transgressing the major planetary boundaries and stable systems. And this could trigger several tipping points in the Earth system that could push us toward a state in which it is no longer suitable for human habitation, for human prosperity.  

As a journalist, I think a lot about how these different phrases—climate change, climate crisis, or the trusty old global warming—might have different impacts. In your work, how do you think about these different terms and their impacts? 

I’ve tried to develop a much more refined and sharp lexicon and terms that we can use. The terms we use are important. There are no innocent terms, and your choice of words can either obscure or elucidate meaning. In terms of “breakdown,” it’s really about the idea that the changes we’re experiencing are unprecedented and could have a large-scale disruption to our socioeconomic systems globally. And that can lead to mass mortality and morbidity. 

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What term do you use most often these days? 

It depends on the audience and what I’m talking about. For instance, the term “existential threat” is very poorly defined and ambiguous. However, when speaking to a public audience, it usually gets the point across more or less that it’s a very big, scary threat that could threaten industrial civilization—or the future of the human species.  

In your paper from last year, you refer to “catastrophic climate change scenarios” and argue that we’ve actually done a really terrible job considering them. I feel like, as a species, we’re pretty good at worrying. Why do you think we’ve turned such a blind eye to these possible outcomes?

There are several possible explanations for this. The goals of the Paris Climate Agreement simply divert our attention toward 1.5 and 2 degrees Celsius, and away from high-temperature scenarios. 

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Additionally, thinking about complex risks, knock-on effects, and thinking about high-temperature scenarios, it’s just harder, it’s more difficult to model. 

On top of that, there’s also the influence of the fossil fuel industry and the merchants of doubt, who have made it incredibly difficult to talk about any kind of catastrophic or extreme climate risk without automatically being labeled alarmist. There is the pressure, as Michael Oppenheimer put it, for climate scientists to “err on the side of least drama.” 

It’s a very big, scary threat that could threaten industrial civilization—or the future of the human species.

How do we try to wrap our heads around such extreme outcomes and such complex factors?

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When we think about catastrophe, about risks or threats, we almost always tend to think about one hazard by itself. It’s important to get away from this simplistic way of thinking, where one often asks: Is climate change an existential risk? 

Of course, that’s a silly question to ask. It depends on a whole bunch of other outside factors. Three degrees of warming in a world marked by equality, trust in public institutions, good adaptive technology and governance, and multilateral cooperation, we could navigate that. Three degrees of warming in a world marked by multilateral conflict, war, dangerous new technologies, polarization, and inequality—that becomes a much more calamitous prospect. 

When we think about breakdown, when we think about risk, we need to think about the overall scenario. And the politics which we find ourselves in are going to impact the overall level of risk. That’s probably sounding pretty nerdy, but it’s important. 

No, that’s really helpful. It was also a helpful reminder in your paper about how so many of these tipping points are interconnected—as you pointed out with COVID or the financial crisis—how these things that seem very separate in our lives now could easily fall, kind of like a web of dominoes. 

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Yes. And it’s important to keep in mind that we don’t need to be overwhelmed or paralyzed by complexity. 

Underlying that complexity is a very simple picture. When we look at the production of risk, things become dramatically and profoundly simplified. There’s almost always a small number of companies and countries who are pushing us toward ecological catastrophe. If you’re looking at global emissions, it’s roughly the top 10 percent of emitters who are responsible for about three-quarters of cumulative global emissions. Roughly a quarter comes from one country: the U.S. If you’re looking at companies, it’s pretty much just the fossil fuel industry that is the big one to blame. About 71 percent of industrial emissions come from 100 companies. And the same goes for a whole bunch of other areas. There’s a really interesting study looking at the finances of deforestation in the Amazon, and you can pick out a couple of key financers—in particular BlackRock—who are essentially funding much of the wholesale destruction of the Amazonian Basin. 

I think there’s a real need to think about this politically and to think about: Who are the actors and the networks in the political economy that are causing global risk and climate breakdown? Then we actually have a startlingly simple and easy picture to deal with. 

That feels like a refreshing way to look at it.

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Refreshing, yes. It’s potentially also disturbing in that these are usually actors and players who are incredibly powerful, right? And that’s probably why we don’t talk about them so much. It’s much easier to blame people and everyday citizens than to blame the U.S. military or BP.

Yeah, I suppose that does make it feel a bit futile when it’s not just up to us and whether or not we’re carrying our own reusable straws.

This is something I used to say to my students back in Australia. If everyone paid attention to turning off their lights, it would barely make a dent in Australia’s emissions. Even if they took a whole bunch of other wholesale behavioral change measures. And if you’re operating under a carbon pricing system, it wouldn’t matter, as the reductions get traded anyway. 

But if everyone in Australia changed the way they voted, then suddenly you could have a target of net zero carbon emissions by 2040 or 2050. Action as a citizen is far more powerful than action as a consumer.

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We don’t need to be overwhelmed or paralyzed by complexity. 

You also study the collapse of past civilizations. Is there one that comes to mind that you think is kind of the most relevant for us to think about currently? 

One problem we have when we look at past societies is we almost always look at small, individual states. For instance, in Jared Diamond’s book Collapse, he has five case studies, and only one of them is actually a larger-scale one, and that’s the Maya, who aren’t actually a single state. They’re actually a kind of cultural zone with different city states. 

Personally, I think the most elucidating and useful parallel is probably the collapse of the late Bronze Age, which involved roughly nine different large-scale polities. The interesting and important thing here is that they were deeply economically and politically connected. Some archeologists have even gone so far as to say that this Mediterranean structure of the Bronze Age was globalized in its own way. 

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I’m a very big fan of Eric Cline’s work on this and how he suggests that what happened in the late Bronze Age was a combination not just of certain threats—like drought, climatic variation, migration, displacement—as well as certain vulnerabilities—rebellion, for instance, and inequality. But also the very structure of the system. In work I did with Eric, we suggest that the interconnectedness of that world actually made them more vulnerable in some ways. Once a sufficient number of city states and trading hubs went down, that created a kind of amplifying feedback, which destabilized the system and made it more likely for more cities and trading hubs to crash, and the entire system basically spiraled out of control. 

And that is potentially my biggest fear going forward: I think our homogenized, interconnected world is very good at buffering against small shocks. But it’s much more likely to amplify a sufficiently large shock into a system-wide crisis. 

Has studying these kinds of looming potential disasters changed anything in the way you live your own life? 

If anything, it has made me much more aware of and cognizant of issues of justice. I think some of the best evidence we have suggests that what really builds resilience in societies is a high level of democracy and participation. It makes for a more flexible society that is much more willing to respond to crises and problems. So, strangely enough, my studies of global catastrophe have made me a much bigger fan of democratization. It’s changed my politics in many ways. 

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That’s interesting. Your background is in international relations and economics, and then you found yourself in the field of disasters. I mean, your main post is at a place called the Center for the Study of Existential Risk. Do these things keep you awake at night? 

Surprisingly, it’s not as distracting or as perturbing as you might think. I certainly had a period of my life, when I was in Copenhagen for the climate negotiations and I had just finished reading Six Degrees. That was a moment which was really fracturing for me—realizing the realpolitik of the world and how incapable we were of actually reaching shared solutions globally, and also just the sheer severity of the problem.

But you develop a certain kind of emotional distance from the problem. And I find, personally, that, like all humans, risks seem much worse and disasters are much worse, when they have a human face on them. I find it much more difficult to read about things like genocide, political violence, and gendered violence, for instance, than I do when I think about 6 degrees of warming—even though 6 degrees, just in the sheer number of fatalities and the sheer number of suffering, could be far, far worse. But it lacks that human element to clearly connect with. 

But what does impact me tends to be the knowledge that these risks are being produced by a small number of powerful actors, usually at the expense of the rest of us. 

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Are you fun at parties? Or are people like, Oh no, here comes the apocalypse guy

I’d be flattered if they said, Hey, here comes Dr. Doom! I like to think that I’m usually quite a cheerful, jubilant Australian.

Katherine Harmon Courage is the deputy editor at Nautilus.

Lead image: Malchevska / Shutterstock

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