False Uncertainty

The New York Times wants to promote dialogue between left and right on climate. This is a worthy impulse. And the person they have hired towards this end, a conservative journalist with a history of climate denial, states in his first piece for the Times that he accepts as “indisputable” the human influence on the observed warming of the earth since the late 19th century. Good.

The rest of Stephens’ piece, though, is a stew of innuendo and misdirection, in service of no apparent goal beyond a smug scolding of some unnamed others’ perceived “100% certainty” on climate.

Who and what is Stephens talking about? The entire climate science literature, including the 2014 IPCC Report (which Stephens cites), is full of statements about uncertainty about virtually all aspects of future climate change. What climate scientist or credible policy maker has ever claimed anything is 100% certain? It would be great if a conservative writer who accepts the science on climate would engage, seriously and sincerely, with real arguments made by credible climate scientists and advocates of climate action on the pages of the Times. Stephens, instead, takes the lazy route, arguing with straw men.

Stephens shows no interest in making constructive arguments in defense of any actual position. He doesn’t articulate any specific view on climate policy, which is what really ought to matter to Times readers of any political persuasion. But one is left to assume he thinks we don’t need to do anything about global warming. Why? Because nothing is 100% certain.

This passes for substantive argument in some circles. Though his acceptance of scientific fact – at least in this piece, if not his prior work – distinguishes him from the climate deniers at the Heartland Institute and Heritage Foundation, Stephens’ strategy is nonetheless the same cynical one as theirs: promote doubt, nothing more. He seems to be saying that liberals (or someone) should be more tolerant of conservative “skepticism” on climate, but that skeptics have no need to justify their views (or even to have any), because it’s ok just to be generally skeptical.

And Stephens is uninterested in applying any of this skepticism to the claims of those opposed to climate action. Presumably referring to (unnamed) proposals for reducing greenhouse gas emissions, he writes that “Demanding abrupt and expensive changes in public policy raises fair questions about ideological intentions.” Leaving aside the crass culture-warring tone – saying those who are in favor of climate action are “demanding” while those opposed are just “raising fair questions” is particularly absurd under the current regime in Washington – how well do we know how expensive any proposed climate policy is? Predictions of the economic impacts of climate policies are far more uncertain than climate projections. The price of renewable energy is dropping much more rapidly than nearly anyone expected a few years ago. Isn’t there some excessive certainty here that could benefit from self-examination?

Perhaps what Stephens means by “100% certainty” is the passion among many for the view that the evidence of a human influence on climate is sufficient to merit a serious policy response. This passion does not require absolute certainty on any aspect of the science, just an intellectually honest view of risk. Because what the genuine uncertainty on climate really means is that while there is a chance future climate change won’t be as bad as the projections say is most likely, there is also a chance it will be much worse.

In no other area of life do we respond to risks by simply assuming the best case scenario. We take out insurance on our homes not because we are 100% certain they will burn down, but because there is a chance they might. Climate should be no different – except that the situation now is more like one in which a wildfire is already spreading towards our house, and we’re just debating whether it will singe the house a little or consume it entirely. How is skepticism a justification for inaction, as long as one accepts at least some possibility that the science is right?

This is the fundamental dishonesty of Stephens’ piece, and of all those who justify inaction by claims of skepticism. It makes no sense to be opposed to any action to mitigate global warming just because there is uncertainty in climate projections. The only way it makes sense is if you’re certain the science is entirely wrong. Or, though maybe you don’t want to say it, you just don’t care, because you’re pretty sure it won’t affect you personally. That is the true false certainty, masquerading as skepticism.

Thanks to Emmanuel Vincent of Climate Feedback for asking me to write this.

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Urgency and Uncertainty in Rolling Stone

Eric Holthaus has a recent piece in Rolling Stone enitled “The Point of No Return: Climate Change Nightmares Are Already Here.” The subtitle is “The worst predicted impacts of climate change are starting to happen — and much faster than climate scientists expected.”

It’s a good article. But it highlights the difficulty of talking about current extreme weather events and their relation to human-induced climate change. On the one hand, the essential message of the piece is to communicate urgency on climate and need for action. This is right and appropriate. And sentence by sentence, the individual statements about specific weather and climate phenomena are accurate (at least those where I have adequate expertise to make an evaluation).

On the other hand, the piece implicitly attributes a lot of individual weather and climate events – all of those it mentions, really, which is a long list – to human induced climate change. Some of those attributions are justified, but others aren’t.

In the cases where the attribution isn’t justified, Holthaus doesn’t explicitly make it, not line-by-line in the sentences talking about those events. I couldn’t find anything outright wrong at that level. The piece was, clearly, researched and written quite carefully and with deep respect for the science. But the attribution is there implicitly, through the piece’s headline, its subtitle, and its overall framing.

I’ve added some annotations at the site Climate Feedback (my annotations and others’ on this piece are not visible yet, as far as I can tell; soon, I think), a new site designed for scientists to evaluate the science content in popular articles on climate. Two of my comments are about Holthaus’ discussion of the ongoing El Niño and positive phase of the Pacific Decadal Oscillation. These two are enough to make the point I’m interested in here.

These two climate phenomena, manifest by slow changes in the sea surface temperature in various parts of the Pacific ocean are indeed having major impacts, as described well in the article. But most climate scientists consider these phenomena to be essentially natural. We can’t be certain that the current instances of El Niño and the Pacific Decadal Oscillation aren’t in any way connected to human induced climate change, but there is no convincing evidence of such a connection, to my knowledge. Holthaus doesn’t say there is one, but to my eye it’s clearly implied. The title and subtitle, as well as the overall framing of the piece, say that it’s a list of impacts of “climate change” – which presumably most will understand to mean “human induced climate change”.

I’m being critical on this issue because it’s one I struggle with myself, and because Holthaus is a thoughtful, serious and committed writer on climate, one who actively seeks criticism from scientists (I understand that he asked Climate Feedback to evaluate his piece). And because while I read the piece as making some implied claims that are outside what science can justify, I agree completely with its bottom line, and appreciate the force with which it comes across.

Human-induced climate change is real, is a grave threat to human society, and is already having significant impacts now. Some of the events Holthaus describes almost certainly do have some imprint of human influence: heat waves and ocean acidification, for example. And natural and human influences can’t be completely untangled. While the heat, drought and wildfire in the west now are likely caused in large part by natural variations in the Pacific sea surface temperature (El Nino and Pacific Decadal Oscillation), greenhouse gas warming adds extra heat, making the impacts worse.

And regardless of the causes of individual extreme weather and climate events now, the disasters they cause still tell us something about our vulnerabilities, and that is relevant to the longer-term climate change question. The human influence will grow larger in the future, as warming proceeds. It will eventually make some kinds of extreme events significantly, detectably more frequent or more intense, even if we can’t clearly detect that influence in individual events of that type happening now. (Tropical cyclones are a good example of this.) The current events can rightly be seen as harbingers, if nothing else.

Holthaus writes quite a bit about the recent paper by James Hansen and colleagues, which warns that sea level rise may occur much sooner and more severely than most of us had thought. This paper is controversial, and not yet even through peer review. But in my view it deserves the coverage it gets, here and elsewhere – its predictions may or may not be right, but it seems pretty clear that we can’t rule them out. Contrary to denialist lines of argument, the uncertainties in climate projections should make us more worried, not less.

What if Holthaus had made a more concerted effort to avoid any implication of human influence on events to which it wasn’t justified? In a piece with the title and subtitle that this one has, the simplest way to do that would have been not to write about those events at all. That would have meant leaving out some of the most serious and visible disasters going on right now in the US, where the main readership for this piece presumably is. Alternatively, the piece could have had a different title and subtitle (my guess is that these were written by an editor rather than by Holthaus himself), one that communicated that the piece was about events of both natural and human origins. Either way, would the sense of urgency have been diluted?

Professional scientists are sometimes criticized for under-communicating the urgency and reality of climate change, especialy when we talk about current extreme events. This criticism is often fair in my view. We talk so much about the uncertainties that we leave nonscientist audiences with the feeling that we don’t know anything. We do this, I think, because we are used to talking to each other. Being clear about uncertainties is an inherent part of scientific practice. Also, our colleagues already share our knowledge and understanding of the big picture on climate change – the consensus is real – so we don’t feel a need to restate that. We fail to recognize that that underlying knowledge is not shared outside our professional circles, and that it’s often appropriate to emphasize what we do know more than what we don’t.

Journalists, on the other hand, are often criticized by scientists (and others) for overstating the connection of extreme events to climate change by glossing over uncertainties – as I have done here, in my first few paragraphs above. This is also often fair, and as with scientists, similarly traceable to the daily realities of their jobs. Journalists are under great pressure to make it current, make it exciting, keep it simple. It’s easy to see how that leads to a little exaggeration and overstatement, whether by implication or outright.

If there’s a perfect solution I don’t know it. I’m glad that writers like Holthaus (and many other good ones) are grappling with the science and doing their best to keep it accurate while still getting the essential message on climate into the popular press. I don’t love everything about this Rolling Stone piece but I think we need more like it anyway.

Full disclosure: Eric Holthaus is an alumnus of Columbia University, where I teach, though I didn’t teach him when he was here and haven’t met him in person to my knowledge. He has interviewed me a couple of times for other pieces he has written, though not for this one in Rolling Stone. He wrote a very kind review of my book when it came out last fall.