From The Michael Slate Show: Scientist Michael Mann on the New Climate Report: “This is a threat to us... here and now”

April 7, 2014 | Revolution Newspaper | revcom.us

Dr. Michael Mann, Distinguished Professor of Meteorology at Penn State University and director of the Penn State Earth System Science Center was interviewed on April 4 on The Michael Slate Show on KPFK Pacifica radio station about the recently released report from the Intergovernmental Panel on Climate Change (IPCC). The following is a transcript of that interview.

Michael Slate: The last report from the IPCC came out seven years ago. Now there’s a new one. What’s changed since then and where are things at now?

Michael Mann: Well it’s really striking when you read this latest impacts report. There are three different parts of the IPCC report: the basic scientific evidence that came out just this last fall; this latest report is on the impacts of climate change, adaption, vulnerability; and next month they will be reporting on the final installment, and that’s on mitigation solutions, what we can do to mitigate the problem of climate change. This latest impacts report was striking, and really just how stark, the stark nature of the terms in which it is laid out. This is a very conservative report by its nature, because this is a consensus of literally hundreds of leading scientists around the world. And so the report reflects almost a lowest common denominator of what all of the scientists can agree upon. In that sense, it’s remarkable that the report states the threat in as stark terms as it does. Basically, what this latest report makes clear, if there were any question, is that climate change is not just some abstract, far off, existential threat. It’s not just something that is going to impact polar bears in the Arctic decades from now. It’s something that’s impacting us here and now negatively. And in a sense, we are the polar bear. We are seeing the negative impacts of climate change, whether you are talking about issues of food and fresh water availability, whether you’re talking about availability of land, whether you’re talking about human health, whether you’re talking about the health of our economy, whether you’re talking about issues of conflict and national security, which after all, are a consequence of competition for available resources. And what the report makes very clear is that if we continue on the road that we’re on right now with ongoing fossil fuel burning, we will see diminished food, water and land and greater competition for diminishing resources among a growing global population. And that’s a perfect prescription for issues of conflict, for basically a national security calamity.

So the IPCC makes quite clear in this latest report that climate change is a big problem. It’s not just that we know that we’re warming the planet, that it’s caused by human activity, the fossil fuel burning and other activities raising greenhouse gas concentration—there is now an established consensus among the world’s scientists that this is a threat to us now, here and now.

Michael Slate: Yeah, that actually came across very clear, and I think it’s something that... one, is that consistently over the years, it’s been consistent like, well yeah, they’re warning us now, but really, what’s the rush, we actually can do something about this. I wanted to ask you about this, it’s bugging the hell out of me, the idea that, talking about climate change, about the temperature rising, change from 2 to 8 degrees Celsius, this span—is that happening now? Is that what’s happening? And what does it mean if it does?

The melting of the Grinnell Glacier in Glacier National Park, Montana. The top photo was taken about 1940, the bottom was taken in 2004. Photo: AP

Michael Mann: Yeah, so we’ve already warmed up, we’ve warmed up the planet just under one degree Celsius, about a degree and a half Fahrenheit so far. It turns out; we are already committed to at least another half degree Celsius, almost another degree Fahrenheit. That’s just because of the greenhouse gases we’ve already emitted into the atmosphere. They will continue to warm the planet for decades, even if we were to stop fossil fuel burning cold turkey right now. We would still see the planet warm for decades into the future, just because of the inertia of the climate system. The oceans continue to absorb some of the heat that we’ve already put into the atmosphere from increased greenhouse gases. So we’re already committed to probably the better part of 2 degree Celsius, a degree and a half Celsius minimum. And what the science tells us is that if we continue business as usual fossil fuel burning for another decade or so, we will almost certainly commit to more than 2 degrees Celsius warming, more than 3 and a half degrees Fahrenheit warming. And that’s an important number because that’s actually the threshold that many organizations and scientists who look at the impacts of climate change will tell you, that 2 degrees Celsius threshold, is where we really start to see some of the most damaging and potentially irreversible impacts of climate change. Again, whether we’re talking about food, water, land, health—across the board, the health of ecosystems, every aspect of our lives, we will see increasingly negative impacts. And so there’s an urgency to this problem unlike anything we’ve seen before. If we don’t act now we likely commit to at least 2 degrees Celsius. If we continue with business as usual, if we just continue to burn fossil fuels without any effort to regulate carbon emissions, to lower our carbon footprints, then what the report tells us is that we could see as much as 4 or 5 degrees Celsius, 7, 8, 9 degrees Fahrenheit warming of the globe by the end of the century. And as my colleague James Hansen, the former director of the NASA Goddard Institute for Space Studies once put it, if we warm the planet that much, it’ll be a different planet. It won’t be the planet that we grew up on. We will be leaving a fundamentally degraded planet behind for our children and grandchildren.

Michael Slate: One of the things you keep pointing to is the idea, or the fact, well there’s two things. The fact that this is actually on the map now. It’s actually concretely happening now in terms of climate change. And I wanted to talk about that, and in relation to, that both what’s happening with food, for instance in the vast majority of the world, which is a constant question. You could see the famines that exist in all parts of Africa and other places. If you’ve traveled through the Third World at all you have some understanding of how desperate some people are for the barest minimum diet. And you guys have been saying this is going to have terrible an impact on crop yield and food. Let’s explain that.

Michael Mann: That’s one of the tragedies here, that in fact the worst impacts, and the impacts that are going to come the soonest, are going to be felt in the developing world, precisely those areas in the tropics where you have nations who are currently struggling to meet their needs when it comes to fresh water and food. That’s actually where climate change initially is going to hit hardest. And some of that is based on really fundamental science. If you warm temperatures even a little bit in the tropics, we know that you see very large decreases, very substantial decreases in the productivity of basic cereal crops. And that’s simply because those crops are already growing at the limit of temperatures, the warmest temperatures they can grow at. And if you warm even a little bit you see sharp drop offs in agricultural yields. And so ironically and tragically, those nations that are least able right now to meet their food needs, we will see the largest decreases. Now we used to think, as recent as the last IPCC report, if you read the chapter on agriculture in the impacts part of the last IPCC report, there was language that suggested that we could actually see increases in agricultural yields in some extra-tropical regions, like the United States, North America, Europe, other areas at higher latitudes. The idea being that you get longer growing seasons in a warmer planet. Winter is shorter, the growing season is longer, and all else being equal, that would seem to imply increased agricultural yields. But something we’ve seen over the past few summers in particular is that any theoretical increase in yields that might result from longer growing seasons appears to be getting completely wiped out by increasingly extreme weather events—more widespread and pronounced drought, over large parts of the U.S., like we’ve seen in recent summers in Texas and Oklahoma. In summer 2011, Texas, their agriculture was devastated. They lost 25 percent of their livestock because of the record 2011 drought. Two summers ago we saw record drought and heat over a large part of our breadbasket and agricultural yields were decimated. And so we now think that even extra-tropical regions where we thought maybe we could see an increase in agricultural yields, even here we will see decreases. And that’s why this latest report comes to a much starker conclusion when it comes to food, our ability to meet our food needs. And again what we’re talking about is a growing global population. And in the face of diminishing food and freshwater, that’s a calamity in the making.

Michael Slate: There’s a point here that gets repeated in the report. I think it’s important for people to understand what’s meant by this. It keeps talking about adaptation and adapting in relation to this. Can you explain what’s going on there? And then I have a follow-up question.

Michael Mann: Sure thing. So our presidential science advisor, John Holdren, who’s a leading scientist, he’s been a very effective spokesperson for this issue in the current administration, I think he once framed the problem best when he said that how we’re going to deal with climate change is going to be a combination of three things. It’ll be some combination of adaptation, of mitigation, and of suffering. And it’s up to us to decide what is an acceptable combination. Now we are already seeing the suffering. There’s a certain amount of climate change that’s already locked in. It’s already happened and there’s more that’s in the pipeline. And what that means is that there’s already some suffering and there’ll be more suffering in the future. It means that we already have to begin adapting, whether we’re talking about building up our coastal defenses against sea level rise and increasingly devastating hurricanes, whether we’re talking about adapting agricultural practices in the face of warming temperatures, worse drought, on down the list. There are a whole bunch of things that we need to start doing to build the adaptive capacity, to deal with some of what’s already in the pipeline and is coming. But, the fact is that if you look at sort of those business as usual projections, if we continue on the course that we’re on, by the end of the century we are talking about changes in climate that are so unprecedented that there’s no amount of adaptation that will basically maintain any degree of resilience in the face of the impacts on food, and water and health and our economy. So the bottom line is, if you look at the projected impacts of this latest report, one comes to the conclusion that adaptation is not going to be adequate. We need to do a certain amount of adaptation no matter what. Because there’s a certain amount of climate change that’s already locked in. But the fact is that there’s a whole lot of other climate change that we can still prevent. And we need to engage in those actions necessary to prevent that. And that means reducing our carbon emissions. That means putting a price on the emission of carbons so that the marketplace will internalize the very real damages that climate change is already doing across the board.

Michael Slate: I was going to ask you, is there a point, is there a tipping point where adapting is clearly impossible, and you spoke to that. It seems to me there’s a dynamic that gets set in motion as well, which would both limit effective responses like, saying effective response would be adapting. But also adds a whole new dimension. I was reading somewhere about the melting Arctic that uncovers organic material that was there, frozen over before civilization began, that is suddenly laid bare and begins to rot and release all kinds of greenhouse gases and just compounds things a tremendous amount. That seems to be something people don’t often talk about, what gets unleashed in the sense of a dynamic that actually gets unleashed to take over.

Michael Mann: Yeah, absolutely. We sometimes call these positive feedbacks although that can be a misleading term to a lay audience that isn’t familiar with the sort of the lexicon of the science. It almost sounds good, “positive feedback,” you know, you get positive feedback from your boss for doing a good job. It’s not a good thing. What it means is that it’s a vicious cycle. It means it’s an aggravating response. And one of the feedbacks we worry about are these so-called carbon cycle feedbacks. And what that means in this case is, as you allude to, if you warm the soils, if you melt the permafrost in the Arctic, well it turns out there’s a whole lot of methane that’s currently locked up in that permafrost. There’s also a lot of methane that is locked up in sort of a crystalline form, solid form, in the continental shelves. And as we warm the planet, as we warm the oceans, and as we warm the permafrost, there’s the potential to destabilize all of that methane that’s currently locked up. Now methane, it turns out is an even more potent greenhouse gas than CO² [Carbon Dioxide]. So if that kicks in, if we start to see those methane feedbacks kick in, then it means we suddenly get even more warming. And that’s not currently really taken into account because it’s too uncertain. We don’t know how to include it in the models because we don’t know exactly how much of that methane is unstable and could be released with even a modest amount of additional warming. So the great example of uncertainty despite what you might hear from critics—and you hear people say, well there’s uncertainty in the science, so why should we take these precautions that could damage the economy? Well, actually inaction is likely to damage the economy a whole lot more. But the fact is that uncertainty doesn’t weigh in our favor. In many respects the uncertainties are such that the problem could end up being a whole lot worse than we currently project. And here’s one good example of that—Arctic sea ice. Right now we are seeing a precipitous decline in the amount of ice that’s left in the Arctic at the end of the summer to the point where if we follow the current trend, within a couple of decades we will have ice-free conditions in the Arctic by the end of the summer. The models say we shouldn’t be there for decades, for fifty years or so. So we are already several decades ahead of schedule in terms of how fast that sea ice is diminishing, and with that decreased sea ice means a fundamental change in the Arctic ecosystems, it means a threat to the animals that rely on that environment, which of course includes the polar bear, walruses... what it means is that we are losing an entire ecosystem. We are losing a unique ecosystem, the Arctic ecosystem, that will not be replaced. What’s the value of the Arctic ecosystem? What’s the value of the Gulf of Mexico? These are the questions we should be asking as we continue to engage in very dangerous drilling of fossil fuel sources and the continued worsening of the climate change problem that’s resulting from that.

Michael Slate: All right Dr. Michael Mann, unfortunately we’ve run out of time but thank you very much for joining us today.

Michael Mann: Thank you, it was a pleasure.

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