I have a professional interest in the philosophical issues raised by the problem of global climate change. I wrote a book on the subject, I give lectures, attend conferences, speak on panels, etc. Yet I often find these events quite frustrating, for reasons that some may find surprising. On many of these occasions, instead of being able to focus on the genuinely difficult philosophical questions raised by climate change (involving primarily the way that we think about our obligations to future generations) I find myself dedicating a large fraction of my time to correcting misinformation. To be clear, these are mistaken beliefs held, not by members of the general public, but often by other university professors.

Everyone knows that misinformation is a serious problem when it comes to debate over the climate change issue. The UN just released a major report on the subject. The report, unfortunately, follows the general trend of focusing exclusively on right-wing disinformation, while ignoring completely the possibility of left-wing disinformation. More specifically, it focuses on climate denialism and skepticism (i.e. views that downplay the severity of the problem) while ignoring the opposite tendency toward catastrophism (i.e. views that radically overstate the seriousness of the problem). This is a bit of a tricky issue, of course, since there is a non-zero chance that climate change will produce genuinely catastrophic outcomes. So when I talk about catastrophism I am referring specifically to views that misrepresent the results of existing climate science, in order to make the high-probability scenarios seem worse than they are expected to be.

There is a temptation to give the latter a free pass, on the grounds that we (i.e. human beings in general) are not currently doing enough to mitigate climate change, and so erring on the side of overstatement, when it comes to presenting the anticipated consequences, seems harmless. Where this attitude becomes a serious problem, however, is when people start to call for regulation, or criminalization, of climate misinformation. This sort of flirtation with illiberalism is a bad idea on its own merits, but from a purely tactical perspective, anyone who intends to use such a strategy against their opponents should want to make damn sure that their own house is in order first. (Elites should have figured out by now that their attempts to exercise coercive control over public discourse, while exempting themselves from the same constraints, is a good way to discredit themselves in the eyes of the public.)

The fact that the call for criminalization linked to above comes from The Guardian is particularly rich, since I have found that newspaper to be a particularly prominent source of climate misinformation. To get a sense of what I mean when I say “left-wing climate misinformation,” consider the role that The Guardian has played in propagating the (false) claim the over 70% of emissions are produced by only a small number of corporations. This claim has its origins in the Carbon Majors Database, which tracks the emissions produced by “the world’s largest oil, gas, coal and cement producers.” The word producers is key here, because the report includes both public sector and private sector emitters. Yet The Guardian reported these figures under the following headline: “Just 100 companies responsible for 71% of global emissions, study says.” If one reads the article carefully, one will discover that investor-owned corporations are responsible for less than half of these emissions, and that of the top 10 emitters, only two of them are private corporations. And yet the average person who reads the word “companies” will assume that it refers to private corporations (not states or state-owned enterprises). As a result, I often run into people who think that large corporations are predominantly responsible for climate change. (I have even seen this claim repeated in peer-reviewed books and articles.)

I call this sort of thing “highbrow” misinformation not just because of the social class and self-regard of those who believe it, but also because of the relatively sophisticated way that it is propagated. Often one will find the accurate claim buried deep in the text, but framed in a way that leads most readers to misinterpret it. Consider the Oxfam report “Who is responsible for climate change?”, which presents the same Carbon Majors data. It leads with the headline claim:

Big Oil knowingly made climate change worse

Wealthy corporations are responsible for recklessly extracting fossil fuels for energy production after centuries of dirty industrialization in Europe and North America—significantly contributing to global climate change.

And then, in the bullet-pointed items that supposedly substantiate this charge, it says the following:

Approximately 71 percent of carbon emissions can be traced to just 100 fossil fuel producers since 1988.

This is technically accurate, but in context, totally misleading. How many readers are likely to realize that of the “100 fossil fuel producers” mentioned, the largest emitters are in fact nation-states and public-sector organizations, not wealthy corporations?

The Guardian, by the way, has persisted in its misrepresentation of the Carbon Majors reports, which makes me think that it must be intentional. The newspaper reported the latest study with the following headline: “Half of world’s CO2 emissions come from 36 fossil fuel firms, study shows,” and this lede: “Half of the world’s climate-heating carbon emissions come from the fossil fuels produced by just 36 companies, analysis has revealed. The researchers said the 2023 data strengthened the case for holding fossil fuel companies to account for their contribution to global heating. Previous versions of the annual report have been used in legal cases against companies and investors.” It’s difficult to see how use of the term “firm” “company” and “investors” in this context can be understood as anything other than intentionally misleading. (Although again, if one reads further down in the article one will learn that state-owned enterprises are by far the worst offenders among the “36 companies.”)

What the Carbon Majors report actually shows is quite a bit more interesting:

I don’t want to belabour this one example too much, the point is to show that there is such a thing as left-wing climate misinformation, and that I’m not just being polemical. Furthermore it’s a problem, because it leads people to recommend ineffectual or counterproductive policies. I have heard both activists and academics calling for the nationalization of fossil fuel companies as a strategy for accelerating the green energy transition, not realizing that this would likely have the opposite effect. Now is not the time to be naive about the public sector! Governments are good at some things and bad at others. Shutting things down is something that they are particularly bad at.

Anyhow, all of this is just a warmup for the issue that I want to discuss, which involves what I think must be the most common piece of highbrow climate misinformation. A very large number of people believe that climate change, under the high-probability “loss and damage” scenarios, within the next few decades, stands poised to lower the standard of living of future generations below what it is today.

Of course this may happen, but it is absolutely not what any of the studies say, or what the IPCC loss and damage reports say. The misrepresentation stems from the way that these studies present their results and how those presentations subsequently get reported.

Consider, for example, the following opinion piece, which I came across in the Globe and Mail last year: “Climate change will knock one-third off world economy, study shows.” The writer makes the following claims: “...most studies coalesced around the view that for every degree of global warming, the world economy would contract by 1 or 3 per cent – challenging, but manageable.” However, there is a new study which shows that “climate change will eventually reduce the value of the global economy by almost one-third, according to Harvard University’s Adrien Bilal and Diego Känzig of Northwestern University.”

Saying that the economy will “contract” clearly implies that we are talking about a net decrease in GDP, like during a recession. Similarly, the idea that one might “knock one-third off” of the world economy suggests that people in the future will be poorer than they are today. But this is not what the study claims.

In order to figure this out, however, one must read the study quite carefully. Turning to the paper itself, things are not much better than the Globe and Mail piece. In the abstract, the authors say: “This paper estimates that the macroeconomic damages from climate change are six times larger than previously thought. Exploiting natural global temperature variability, we find that 1°C warming reduces world GDP by 12%.” In the same vein, the introductory section says the following: “Climate change implies a precipitous decline in output of 46% by 2100. Capital shrinks by 37% and consumption drops by 37%, leading to a 25% welfare loss in permanent consumption equivalent in 2024” (p. 5).

Again, this all sounds like people are going to be getting poorer. Economists who work in this area know that this is not what the paper is claiming, but the non-specialist is likely to be misled. You have to read much, much further into the paper before the crucial qualification gets mentioned: “Figure 14 presents our main results. Panel (a) depicts the path of global mean temperature. Panel (b) reveals that output drops rapidly as global temperature rises, relative to a world that is not warming. In 2050, output declines by 19%. In 2100, output is 46% below what it would have been without climate change” (p. 39).

Here you have the same claim that was made in the introduction, about economic output being 46% lower in 2100, but with the important clarification, that the authors are not talking about it being 46% lower than it is today, but rather 46% lower than it would have been, in 2100, in a world without climate change. But it is still going to be larger than it is today! When the authors say that between now and 2050 “output declines by 19%” they do not mean that it literally goes down. Based on underlying growth trends, world economic output is likely to double by 2050. What the authors are saying is that, rather than just the expected increase of 100% between now and 2050, the world economy could be increasing by 119% if there were no climate change. In this respect, climate change will “decrease” output by 19%.

Of course, many people will choose not to believe these projections about GDP growth. Environmentalists have been predicting the end of growth since before I was born. The observation that I am making here is the much narrower one – that the results of this study are being misreported and misunderstood, which is causing the average educated person to have false beliefs about the assumptions that structure environmental policy debates. This paper is not an isolated example. One can find exactly the same misreporting in David Wallace-Wells’ piece, “The Uninhabitable Earth,” which discusses the widely-cited 2015 Nature paper by Marshall Burke, Solomon Hsiang, and Edward Miguel:

This is the sterling work in the field, and their median projection is for a 23 percent loss in per capita earning globally by the end of this century (resulting from changes in agriculture, crime, storms, energy, mortality, and labor). Tracing the shape of the probability curve is even scarier: There is a 12 percent chance that climate change will reduce global output by more than 50 percent by 2100, they say, and a 51 percent chance that it lowers per capita GDP by 20 percent or more by then, unless emissions decline. ... The scale of that economic devastation is hard to comprehend, but you can start by imagining what the world would look like today with an economy half as big, which would produce only half as much value, generating only half as much to offer the workers of the world.

The last sentence makes it clear that Wallace-Wells has misunderstood the paper, since what Burke, Hsiang and Miguel actually said is that “unmitigated warming is expected to reshape the global economy by reducing average global incomes roughly 23% by 2100... relative to scenarios without climate change.” People are still going to be several times richer, they are just going to be 23% less rich than they might have been.

In fact, you have to search a little bit to find mainstream media reports that actually state the results of these studies correctly. Given this dismal landscape, the authors of the VoxEU piece “Economic Losses from Climate Change are Probably Larger Than You Think” should be congratulated for reporting the results both accurately and clearly. They begin with the following survey of the basic models (including Bilal and Känzig):

In the absence of further climate mitigation action (i.e. if only currently implemented policies are maintained), the global economy could lose as little as 2% or as much as 45% of total output due to climate change by the end of the century, depending on the damage function underlying the projection. These estimates represent global losses against a hypothetical baseline without further climate change (i.e. a scenario in which no further warming occurs).

In case that last sentence is not clear, they add a footnote: “This means that even the most adverse damage function does not present a degrowth scenario, because the baseline sees the global economy growing considerably by the end of the century.” Again, the authors should be congratulated for clarifying this point, which is absolutely not understood by most people.

All of the confusion and misinformation on this issue interferes with my work, because one of the major normative challenges posed by climate change involves thinking about the tradeoffs between the short-term benefits of economic growth and the long-term harms of climate change. Furthermore, because future generations are still expected to be better off in the aggregate, by the end of the century, under the most probable scenarios, simple deontological approaches (like plain-vanilla Rawlsianism) are inadequate to address the issue. Climate change involves a straightforward failure of maximization, but if one is not committed to maximizing the well-being of future generations, it becomes rather difficult to say what one should be doing about it.

As far as the misinformation is concerned, the important lesson to be drawn is that our epistemic environment has been severely degraded over the past decade, with the result that many traditionally trustworthy media sources have become a great deal less so. People who believe that only the right-wing epistemic ecosystem is impaired are deluding themselves. The populist right may be particularly bad, but the rot is everywhere. Getting one’s information from legacy media rather than social media offers no immunity. Newspapers in particular are simply not as trustworthy as they used to be – those that are still solvent have suffered a precipitous decline in the number of staff, with attrition particularly concentrated among older employees. So while there remain obvious differences in trustworthiness between different media sources, the days in which one could uncritically believe whatever one read in The Guardian or the Globe and Mail (or heard on the CBC) are long gone.