Leading Climate Scientist Michael Mann separates myth from reality in climate change reporting

transcript

DIMITRI LASCARIS: This is Dimitri Lascaris for The Real News. On July 9th New York Magazine published a grim assessment of humanity's future. The lengthy article authored by David Wallace-Wells was entitled The Uninhabitable Earth. The article began with these ominous words, "It is, I promise, worse than you think. If your anxiety about global warming is dominated by fears of sea level rise, you are barely scratching the surface of what terrors are possible even within the lifetime of a teenager today. Absent a significant adjustment to how billions of humans conduct their lives, parts of the Earth will likely become close to uninhabitable and other parts horrifically inhospitable as soon as the end of this century."So how bad is it really?

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Now here to impact this dire assessment of humanity's future is Professor Michael Mann. Professor Mann, a frequent guest on The Real News, is a distinguished research professor and a director of the Earth System Science Center at Penn State University. He's the author of the book The Hockey Stick and the Climate Wars, and his latest book, coauthored with Tom Toles, is titled The Madhouse Effect: How Climate Change Now is Threatening Our Planet, Destroying Our Politics, and Driving Us Crazy. Thank you again for joining us Professor Mann.

MICHAEL MANN: Thank you. It's good to be with you.

DIMITRI LASCARIS: According to David Wallis-Wells, his piece in New York Magazine was based on, and I'm quoting him, "dozens of interviews and exchanges with climatologists and researchers in related fields, and reflects hundreds of scientific papers on the subject of climate change." Wallis-Wells went on to say that his piece is a portrait of our best understanding of where the planet is heading absent aggressive action.

However, you've written a somewhat critical response to this article. Your critique of the Wallis-Wells piece in the New York Magazine can I think be broken down into two themes. The first broadly speaking is about factual errors that you've identified within the article, and the second relates to the rather pessimistic tone of his article. I'd like to start with the factual errors. What do you consider to be the most important factual errors in this New York Magazine piece?

MICHAEL MANN: Yeah, and I don't see those two things as necessarily being independent, because my assessment is that those factual errors all sort of were in the same direction of implying a narrative of a future climate that is worse than what the science objectively supports. As I've said, the truth is bad enough. We don't have to exaggerate it to make the case that there is a great urgency in acting on climate change.

Some of the specific errors were his mis-citation of a single study that simply demonstrated that one data set that had showed less warming than all the other data sets was in error, and when it was fixed it actually showed the same warming as the other data sets. He described that study as showing that the Earth is warming twice as fast as we thought, and that's simply not the case. It only showed that the one flawed data set that was underestimating the warming was in line with the other data sets, and moreover the warming that we're seeing is in line with what climate models have projected we're likely to see as we continue to burn fossil fuels and increase greenhouse gas concentrations. That's a case where, again, the error was used to sort of help motivate a narrative, a somewhat overly doomist narrative.

The same thing is true in his assessment of so-called carbon cycle feedback. What do I mean? There is methane that's trapped in the permafrost, and as the Earth warms up some of that methane is likely to be released, and since methane itself is a greenhouse gas, a potent greenhouse gas, that can further increase the warming. It's what we call a positive feedback, which might sound good, but it's bad. It's a vicious cycle. It adds to the warming.But in his piece, he sort of quoted ... He cited a really fringe viewpoint that argues that there's so much of this methane out there that could be readily mobilized that it could double the amount of warming that we're likely to see in the decades ahead, and that just is not objectively supported by the science. The objective science that's out there suggests that, yes, this stuff exists and some of it will be released, but the main driver of warming in the foreseeable future is going to be the CO2 buildup from our burning of fossil fuels.

There are other errors. There was a panel of 14 leading climate scientists who evaluated the article for accuracy for the site Climate Feedback, which is sort of a watchdog independent site that evaluates the scientific merit of articles on climate change, and the overall score was a negative .8, which is very low on the accuracy scale. It was judged as being somewhat inaccurate as an article.Now that alone is not necessarily a problem if the errors are honest ones and they're sort of ... Act to sometimes make things sound worse, sometimes sound better, but the errors all were in the same direction of implying, again, a narrative of a far gloomier future than the one that we would likely see. The one we'd likely see is still a bad future. If we don't act on this problem now, we're going to see a lot of bad things happen, and a lot of bad things are already happening.

But he sort of took what was an absolute worst case scenario and made it seem like it was a probable scenario. My worry is that when you do that and you make it sound like this is an unsolvable problem and there's nothing we can do to prevent this disastrous future it actually leads us in the same direction as outright denial of climate change. It leads us down a path of inaction.

DIMITRI LASCARIS: Because people sort of adopt a fatalistic attitude and say there's nothing we can do about it at this stage? Let's play devil's advocate for a moment, and I certainly appreciate your point ... Two points that you made amongst others, one of them being that it's difficult to disentangle the factual errors from the pessimistic tone, and also that we have to be ... It's imperative that we be faithful to the science, and I readily accept both of those points.

But one might also argue, taking those points as a given, that the whole reason why we find ourselves in this mess is that we have suffered both as a species, and certainly at a governmental level, from an appalling degree of complacency. Isn't there something to be said for highlighting placing greater emphasis on worst case scenarios, ones that are supported by the science, but highlighting the worst case scenarios to try to light a fire under policymakers and get them to act with the requisite degree of urgency?

MICHAEL MANN: Yeah. Let me state, by the way, that this article was not an egregious example of the phenomenon, but it was a very widely publicized example. That's why I thought I had to weigh in on it. The author, who is a good author and I'm ... A good writer and has a history of doing really good journalism and I think sort of bought into a misframing in this particular case, but it's really a far more moderate example of a narrative that one does find out there, which is extremely unhelpful, folks like Guy McPherson, who's an ecologist. He's become sort of a cult hero to the doomist crowd. My understanding is he had some influence on this article. The author talked with McPherson.

McPherson has argued that all life on Earth will be destroyed within 10 years and there's nothing we can do about it because of exponential climate change, that has no basis at all in scientific fact. In the case of McPherson, he literally is arguing there's nothing we can do folks. His prescription is no different from the prescription of fossil fuel industry funded climate change deniers who say there's no reason to act.

In the case of the New York Magazine article, not nearly that egregious, and I do agree with much of what you've said. I think there's sort of a fine line there. We do need to talk about worst case scenarios. I've written articles about how it's important to look at what we call the fat tale. If you look at the probability distribution of impacts, it doesn't drop off to zero when you go to very large impacts. It drops off very slowly, and that means there's a small but finite probability of changes that are far worse than what we are currently projecting with state-of-the-art climate models.

That has to be taken into account. You have to take into account the fat tale of risk when you do sort of the cost benefit analysis of acting on this problem. It's similar to why we buy fire insurance for our homes. Not because we think our home burning down is a likely scenario, it's because if our homes did burn down, although it's an unlikely scenario, it would be so catastrophic that it makes sense to hedge against that low probability, high cost scenario by investing now in fire insurance. Arguably, those sort of worst case scenarios can play a similar role in informing our mitigation of climate change as a planetary insurance policy.

I support that framing, the framing that does talk about worst case scenarios and the impact that they should have on our assessment of risk. That having been said, my main criticism was that it seemed to equate at times what was in fact a worst case scenario with a likely scenario, and in fact the likely scenario as far as many are concerned is that first of all just looking at the data carbon emissions have actually plateaued now. They're not following that ever upward trajectory that we were on five or ten years ago, so a most likely scenario of the future is not a scenario where we burn all of the available fossil fuels. It is pretty clear that is not the pathway that we are now on.

The fact is that there is a great urgency to this problem and we do have to bring down our carbon emissions rapidly. Plateauing isn't enough. We've got to bring them down to zero or near zero by the middle of this century if we're going to avoid the worst impacts on climate, but there is a path for doing that. There's a very real path forward for doing that in the wake of the Paris Agreement and the commitments that were made by the nations of the world to act on this problem. There is a very clear path forward for averting catastrophic climate change and it's very important that we don't tell people otherwise, because that leads to despair and ultimately it can become a reason for inaction.

DIMITRI LASCARIS: I want to focus in just a ... Push forward with this theme a little further on a particular passage from his article. He says, "The IPCC," that's the Inter-Governmental Panel on Climate Change, "reports," and these are the reports that are widely considered the gold standard of climate science, "don't fully account for the albedo effect," and in parenthesis he says, "less ice means less reflected and more absorbed sunlight, hence more warming. They don't account for more cloud cover which traps heat, or the dieback of forests and other flora which extract carbon from the atmosphere. Each of these promises to accelerate warming and the history of the planet shows that the temperature can shift as much as five degrees Celsius within 13 years."

From a scientific perspective, do you agree with this commentary about the IPCC reports and its implications. If so ... Sorry, go ahead.

MICHAEL MANN: Yeah. No, that whole passage unfortunately is riddled with some inaccuracies. First of all the five degrees Celsius change in temperature he was referring to was local. It was associated with an event known as the Younger Dryas event, which was largely localized in the north Atlantic. There's no evidence that there was a five degrees Celsius change in global temperature, so this is a common problem of equating regional changes in climate that can often be quite large with global scale changes, so that's not accurate.

The larger point, the one that you're asking about, is whether or not the IPCC has neglected key sort of processes that are relevant to climate change, and that's not true. The claims that he made that it's not representing the carbon cycle and the role of vegetation and that it's not representing the loss of the reflective property of ice as ice is melted away, that's simply not true. Those processes are very much in the models.

Now there's a grain of truth to his criticism, and my sense is that he took what was sort of legitimate criticism and didn't get it quite right when he translated it. A legitimate criticism is that the models are not fully capturing those processes. They're not fully capturing some of the processes related to the carbon cycle and vegetation and ocean biological behavior. There are all these interactions between life and the climate that are important to take account of, and not all climate models do a very good job in accounting for those so called interactions between the climate and the carbon cycle, and I think he's alluding to that.

They do account for them in general, just not perfectly. A lot of the representations are imperfect, and that's the legitimate place for criticism. With regard to the melting of ice, they very much take into account the melting of ice and the lowering of this albedo effect that comes with that. That's another positive feedback, not a good thing. It means an amplifying feedback that accelerates the warming, but that is in the models.

What is true is that the models are not quite capturing the rate at which we are seeing arctic sea ice melt away and there's some interesting discussions within the scientific community about why that might be the case. They do not yet properly account for the loss of ice from the ice sheets, because it's very difficult to run a climate model in real time and have it coupled to a model of the continental ice sheets which are ... Just modeling those mathematically is a very computationally expensive process, so it's very difficult to run a model ... Project over the next hundred years with a climate model that has an interactive carbon and an interactive ice sheet representation.

What that means is that those sorts of contributions, the role of the ice sheets, often has to be represented in a somewhat approximate way, and it's possible that we are underestimating the contribution that the melting from ice sheets could make over the next century or two. There is a legitimate point to be make there that the models are not fully capturing those processes, but it's wrong to say the models are ignoring them, as if we know these things exist and we've just decided not to account for them.

Modelers are accounting for them as best they can, but there are legitimate criticisms about whether we're fully accounting for all of the subtleties associated with these processes.

DIMITRI LASCARIS: You've identified ... Lastly, I'd just like to ask you this about this article. I mean you've identified some quite significant factual errors and overstatements and so forth and you've talked about the 14 climate scientists giving a rather negative assessment of the accuracy of the article. Has New York Magazine issued any kind of a correction of the article?

MICHAEL MANN: Not to my knowledge. I think they did say ... They solicited a letter from me that they were going to publish a series of commentaries or letters and then I heard back from them that they weren't going to do that. Instead, they were going to publish a summary of some of the critiques, so I do think that's forthcoming. I still view New York Magazine as one of our finest publications and this journalist is an excellent journalist.

All of us at times make mistakes and don't do our best, and I think this is just an example of where there was a lost opportunity, that with a little bit of additional vetting this could have been a ... I think a far higher quality article which would have still had an impact on the conversation, but which would have also had the support of the scientific community. That's important, because people ultimately do want to know if these scenarios are grounded in good science. And when the scientists ... Not just me, but my colleagues come back and say no, there are these problems, it actually does undermine the authority of that article, so it is important to get this stuff right.

DIMITRI LASCARIS: Right. Well I hope that we can take the opportunity following this discussion to talk a little bit about some of the current weather phenomena and climate characteristics that we're seeing in this year, and particularly this summer, so I'd like to come back in part two and explore that with you.

MICHAEL MANN: Okay.

DIMITRI LASCARIS: Thank you very much Professor Mann. This is Dimitri Lascaris for The Real News.

Dr. Michael E. Mann is Distinguished Professor of Meteorology at Penn State University, with joint appointments in the Department of Geosciences and the Earth and Environmental Systems Institute (EESI). He is also director of the Penn State Earth System Science Center (ESSC).