Starr Forum: The Madhouse Effect

Michael Mann speaking at MIT

MICHELLE ENGLISH: Welcome to today's MIT Starr Forum with Michael Mann, who will be discussing his latest book The Madhouse Effect, How Climate Change Denial Is Threatening Our Planet, Destroying Our Politics, and Driving Us Crazy. Today's event is sponsored by the Center for International Studies. I'm Michelle English, and I'm thrilled that you're here for this important conversation. Before we get started, I'd like to mention that we have a Starr Forum next Thursday, March 14th with Ambassador Michael McFaul on his latest book Cold War and Hot Peace, an American Ambassador in Putin's Russia. Details for this talk and others can be found outside in the foyer and if you haven't already and are interested, please go ahead and sign up to be on our email list.

As per our typical format, we'll conclude the talk with a Q&A and for the Q&A I just wanted to remind everyone to line up behind the mics and to be prepared with only one question so we can get everyone's question answered. And immediately following the Q&A, we will be doing a book signing, which if you haven't had a chance to purchase Madhouse Effect yet, please purchase the book over here. Thanks to MIT Press for coming and selling books for us.

It's an honor to introduce our speaker, Michael Mann. Professor Mann is a distinguished professor of atmospheric science at Penn State with joint appointments in the department of geosciences and the earth and environmental and Environmental Systems institute. He is also director of the Penn State Earth System Science Center. He is author of more than 200 peer-reviewed and edited publications, numerous op eds, and commentaries and four books, including Dire Predictions, Understanding Climate Change, The Hockey Stick and The Climate Wars, Dispatches From the Front Lines, and The Tantrum That Saved the World. Please join me in welcoming Michael Mann.

MICHAEL MANN: Thank you very much. My microphone working there? Great. Well, thanks again. It's great to be back at MIT. I always enjoy my visits here. I'm going to be talking about a book or a topic, the Madhouse Effect. Now, this is a book that we published in the fall of 2016. And at the time, I was criticized by some colleagues, because this is a book about climate change denial. And many of my colleagues said, you know, why are you talking about climate change denial? We're past that. We've won that battle, and now it's going to it's going to be about solutions and action.

And of course, history had something else in mind, because we elected our first climate change denying president ever. And so we are certainly back in the madhouse of climate change denial. In fact the title of the talk is the MadHouse Effect Climate Denial in the Age of Trump. Well, let's talk a little bit about the science. In fact, let's talk about science itself, how does science work. That's sort of the first chapter of the book is about skepticism.

Skepticism is a good thing in science it's the self-correcting machinery that Carl Sagan talked about that helps science stay on track, on a course toward a better understanding of how the world works, how nature works. And too often, we allow those who are not skeptics-- the wholesale rejection of the overwhelming consensus of the world's scientists based on the flimsiest of arguments that don't hold up to the slightest bit of scrutiny, that's not skepticism. That's contrarianism or outright denial, denial of science.

There's a great quote here attributed to the great Carl Sagan-- "the fact that some geniuses were laughed at does not imply that all who are laughed at are geniuses." You guys are at MIT, you understand basic logic here. Those two things aren't equivalent. In fact, they laughed at Columbus, they laughed at Fulton, they laughed at the Wright brothers, but they also laughed at Bozo the Clown. Many of you in the audience are old enough like me to remember Bozo the Clown.

And for every Galileo, every true, Galileo every paradigm breaking scientist who revolutionizes our understanding of the world and the universe, there are thousands of Bozo's the Clown. And in today's world, too often, they have access to a megaphone that amplifies the most fringe of viewpoints when it comes to issues like climate change. So denial of the basic science, that's not skepticism. What about the basics?

We are about as certain about climate change-- in fact, there was an article just published within the last week that shows that we've exceeded the 5 sigma limit in terms of our confidence that humans are changing the climate and warming the planet. And that's about as high a degree of confidence as anything in science. We're as sure about climate change as we are about the theory of gravity. And I say that and I make that analogy seriously, because there are still uncertainties in the theory of gravity.

There are still uncertainties. We haven't unified all the forces. We don't have a comprehensive quantum theory that incorporates gravitation. We've never measured to graviton. It's a huge uncertainty. And we can't account for a huge fraction of the mass in the universe. So there are uncertainties some pretty big uncertainties in gravity. That doesn't make it safe to walk off a cliff, does it? And yet, there are those who would have us walk off the metaphorical cliff of not acting on climate change based on similar levels of uncertainty.

So why should we care? It's not just about polar bears and penguins. And I do care about polar bears and penguins. I care about leaving behind a world that has the beauty and wonder of the world that I grew up on for my daughter, her children and her grandchildren. But it's not about way far off things in the Arctic that we never see, that seem distant in space and time. It's about things that are happening now like unprecedented drought in California, the worst drought in at least 1,200 years as far back as the tree ring folks can go.

Now I have some colleagues who say, well, you know, maybe it's just a natural. Things come and go. Maybe this drought, this unprecedented drought is part of the natural variability of our atmosphere and our climate, but it seems unlikely. We know that when you warm up the soils, you evaporate more moisture. When you warm the Arctic, as we'll see later on, you can actually change the jet stream in a way that diverts storms to the north of California, denying it the rainfall and the snowfall that it would normally get.

So worst drought in at least 1,200 years in California, the worst drought in at least 900 years, as far back as they can go, in Syria. The tree ring records take them back 900 years. And the current drought is unprecedented as far back as we can go. We have a president who has said that we shouldn't be diverted by sort of unimportant issues like climate change. We need to focus on the threats, the real threats, like international terrorism.

Well, there's a deep fallacy and that sort of statement, because in fact, climate change is what our national security community refers to as a threat multiplier. It takes existing, threats existing tensions, and it exacerbates them. This drought in Syria forced rural farmers into the cities where they were competing with the people who already lived there for food and water in space. Increased competition for resources leads to conflict. An atmosphere of conflict provides a perfect breeding ground for terrorist organizations looking to recruit people. And that was the context in which ISIS arose. So in fact, in a very real sense, the most pressing issues today in terms of conflict and terrorism, there's a linkage there with the stresses created by human caused climate change.

Unprecedented wildfires, as I've said, in California, the worst wildfires on record over the past few years. The two worst wildfires on record in fact-- regardless of what metric you're using, area burned, the cost of the damage, loss of life, each of those records has been broken over the past few years in California. And in fact, there's been a threefold increase in the area of wildfire in the Western US over the past few decades.

Well, and our president of course as you may remember dismissed that as the problem is you are just not sweeping up the leaves, that's the underlying problem. And if we could just do a better job raking leaves, then we could relieve unprecedented wildfires in California. Of course, Tom Toles, Tom Toles can never resist weighing in on the politics of these things.

Well, unprecedented drought and wildfire. But at the same time, a warmer atmosphere holds more moisture. So when you do get a rainfall event, you get more of it. And this is something we expect, and it's not a contradiction. You get worse drought, wildfire in the Western US, but the potential for larger rainfall events, larger flooding events like we saw this winter in California. When it does rain, you get more of it in short periods of time.

And indeed, we've seen unprecedented super storms. Maria, this is the face of climate change. Climate change is not a far off distant threat up in the Arctic only impacting polar bears. It is impacting us now in terms of increasingly destructive tropical storms and hurricanes. And I happen to say that here in this room, I'm a little intimidated because my good friend and colleague here Kerry Emanuel, who is the world's leading scientist in our understanding of the relationship between climate change and changing tropical storm and hurricane characteristics-- and there is a linkage there.

There's also a linkage with the rainfall. As I said before, if you warm up the atmosphere, it can hold more moisture. So it's not a coincidence that the two worst flooding events in history the United States have happened over the past two years, Hurricane Harvey, unprecedented flooding event in Houston two years ago and Hurricane Florence a year ago. These storms produce more rainfall. So that's the threat. That's why climate change is a problem.

And yet, we haven't acted to the extent necessary, in part because there has been a very organized, well-funded effort to discredit and deny the science by vested interests who understandably would like to see us continue with our addiction to fossil fuels. They're profiting greatly from that addiction. And they don't want to see us move away towards renewable energy. And so we have been dealing with decades of orchestrated denialism.

And often, there is sort of a progression. I call these the stages of denial. The first stage is that it's not happening. How many people here have heard the claim that there's a pause in global warming? Raise your hand. Let's talk about that, pause in global warming. Well, let's see. What did the data actually show here?

2014 was the warmest year on record until 2015, which was the warmest year on record, until 2016, which was the warmest year on record. The good news is that 2017 was not the warmest year on record. It was only the second warmest year. And 2018 was only in the top five. So it's a cooling trend. It's a cooling trend, the globe is cooling. The argument you hear is, well, OK, it was very warm. We had a few warm years in a row. But you know, there's natural variability. There's natural variability in the climate system. Maybe this is natural variability.

Well, my co-authors-- and frogs understand that. Stove top temperatures do change naturally. They could it could be a natural cycle. They should just wait it out, they'll be fine. Well, we actually did an analysis a couple of years ago. We estimated the likelihood that we would see three consecutive record breaking years like 2014, 2015, 2016, if it were just the natural variability of the climate system.

And we used a combination of climate models and actual climate observations to sort of estimate those probabilities. And you can use control simulations where you're not increasing the greenhouse effect and other experiments where you're increasing greenhouse gas concentrations to see how likely that would happen, how likely that would be, both with and without the effect of human caused planetary warming. Now, I would read you the abstract of our paper and talk about the p-values in our analysis.

But I think probably the easiest thing to do is to just put up the headline of this discover article that summarized our findings in terms of the likelihood of that record warm streak-- "A Snowball's Chance in Hell That This Was Natural." It's a pretty good technical summary of our findings. And the snowball is a good analogy, because we do, after all, have a senator who believes that if you introduce a snowball on the Senate floor, that somehow disproves 200 years of basic physics and chemistry and science.

Well, it's not natural. We know it's not natural. We can't explain the warming that we've seen from natural variability. And another version of this is, OK, well but maybe the impact, sea level rise. It could be rock stumbling into the ocean. You can't rule that out. You have to consider every hypothesis in science, you really do. You have to be open minded.

Moe Brooks actually represents the district that Huntsville, Alabama is in. I actually gave a talk there a few months ago shortly after he had made that statement. And I did try to abuse the people in his district of the notion that this is due to rocks falling into the ocean. It's not. But The Wall Street Journal shortly thereafter ran an editorial, "The Sea is Rising, but Not Because of Climate Change--" an op ed rather by Fred Singer, climate change, yes, a name that evokes a strong response sometimes, "The Sea is Rising, Not Because of Climate Change."

Now we wrote a letter to the editor in response to that. And I wanted the title to be that "Objects Are Falling but It's Not Due to Gravity," "Continents Are Moving, but It's Not Due to Plate Tectonics," because that's about as reasonable as "The Sea is Rising, not Because of Climate Change." Well, they did publish a letter of response. And I know that at least one person other than my mother read the letter to the editor, because they were sitting next to me on a flight to Cleveland that day. This person was actually reading our letter.

Well, continuing with sea level rise, well, maybe it's self-correcting. Maybe the whole problem is self-correcting, right? If sea levels rise enough to snuff out all of the coal-fired power plants, it's a self-correcting process. After a couple hundred feet of sea level rise, we should be fine. Well, no, it's not self-correcting in a meaningful sense.

It's not a good thing, that's the next line of argument. OK, well, maybe it's a good thing. And I know what you're thinking, it's like, OK. No serious politician would try to argue that global warming is a good thing, right? I mean, it's obvious. We've seen these unprecedented extreme weather events, devastating wildfires and super storms, droughts and heat waves." no serious politician would actually try to say that global warming is a good thing.

Well, no current politician, Scott Pruitt is no longer our EPA administrator. He was asked to resign some months ago. Don't shed any tears for him. He very quickly found an cushy job in the coal industry as soon as he left. Oh, right, well, melting ice sheets lift all boats. It's a good thing. Unprecedented super storms and wildfires and heat waves, they're a good thing. Wildfires in the Arctic? Nothing to see there, folks. Unprecedented floods all around the northern hemisphere this past summer, floods, heat waves, all time records shattered.

And we talked just a little science here. So some of our own research has been looking at these unprecedented weather extremes, because some of it you can understand. Some of it's pretty simple. As I said, you warm up the atmosphere, it can hold more moisture. So you're going to get bigger rainfall events. You warm up the ground, it's going to evaporate more moisture, you get worse drought.

You warm up the planet, you're going to shift the bell curve over. And so you get more of those extreme events in the far right tail of the bell curve. You see a large increase in the frequency and intensity of heat waves. That's all pretty easy to understand. But there's something else that's been going on here. And the climate models don't do a good job capturing this.

If you look at the most devastating extreme summer weather events that we've experienced over the past two decades, what they've had in common is a very unusual pattern to the jet stream where you get very large amplitude waves-- we call these raspy waves or planetary waves-- very large amplitude waves in the atmosphere that remain stationary. They sit in the same place. And so you've got a deep high pressure. It's heat and dryness, drought baking the ground day after day in the Western US, or you get this trough back East, which gives you unprecedented rainfall, like we saw in State College.

As California was baking in those wildfires we're breaking out, much of the East Coast was experiencing unprecedented rainfall. Quabbin Reservoir not far from where I grew up in Western Massachusetts, all time highest level ever observed. That's because this trough was sitting over the Eastern US day after day for a large part of the summer. And our own work has shown that, believe it or not, the way-off distant warming of the Arctic could seem so remote maybe changing the northern hemisphere jet stream in a way that favors these very high amplitude stationary wave patterns that give you these unprecedented weather extremes.

And that's not captured well in the climate models. If you look at the key mathematical term in the equation that describes this behavior, the average error in that term in current generation climate models, like those used in the most recent IPCC report, is over 300%. So the models can't be capturing this mechanism properly, not at the resolution that they're typically run in these climate change experiments.

And sometimes, there's surprises that in store. We don't really think about it until we take a retrospective look at things. So our schools were closed. They had to renovate the schools in our town this summer. There was the danger that school was going to be starting late this fall because of these expensive renovations because of a huge mold outbreak due to, again, this unprecedented rainfall and wetness.

Climate change is now impacting us in all sorts of ways that we don't necessarily even realize. The impacts are no longer subtle. We're seeing them play out on our television screens in our newspaper headlines and our social media feeds and in our own hometowns. We're already seeing profound impacts of climate change in our daily lives. And that's just one example.

And that same factor that I talked about-- as the jet stream potentially slows down, we think that that might be playing a role in some of these cold air outbreaks, the polar vortex. You've heard about the breakdown of the polar vortex, which allows these cold arctic air mass masses to just drift down into lower latitudes. We think that climate change might actually be playing a role there by weakening the northern hemisphere stream, weakening the polar vortex so that those arctic air masses can sort of slip down into lower latitudes. That science is still being debated among scientists, but there's a potential linkage there.

And so it's somewhat ironic when our president, for example, says that these cold conditions disprove climate change. They might actually be symptomatic of it. And let's put it in perspective, because we didn't see record breaking cold despite what you might think. Those of us who remember the 1970s realize that what we think about today as record cold is really little more than old fashioned cold, the sort of cold that used to be very common. The planet has warmed so much that people, millennials and folks are younger than that, don't have within the range of experience those sorts of conditions.

But they're not unprecedented. It's true that during January during that cold air outbreak, there were two records broken, all time cold records broken in the US for two towns in Illinois in the month of January. Those were the only two cold records set around the entire globe in 2019. In that same month, there were 35 all time records for warmth that were broken in the southern hemisphere where it was summer, in Australia, South America, and South Africa. That's a ratio of 35:2 warm to cold.

In an unchanging climate, that ratio should be 1:1, but it was 35:2. So if you want to talk about extreme temperatures, extreme temperatures we saw in January are an overwhelming affirmation of what we expect to see in a warming planet. And warmer atmosphere holds more moisture. In Boston in the winter, that precipitation is going to typically be snow. But if the Atlantic Ocean is warmer, there's more moisture in the air.

And if the Atlantic is warmer and you have a cold arctic air outbreak, you're going to have a clashing of very cold and warm masses of air that are going to lead to intense storms, like nor'easters. And there's some evidence that we are likely to see stronger nor'easters in a warming climate. And those nor'easters are going to have warmer oceans to feed off of, giving us larger amounts of snowfall.

The season of snow cover gets is getting shorter and shorter, but individual snowfall events are actually likely to get greater under these conditions. And these record nor'easters with record snowfalls that we've seen in Boston and Washington DC along the US east coast if anything are an affirmation of the science , not a contradiction to the science.

And then the final stage of denial is, well, it's too late to do anything about this anyway. We spent so long debating the science. And I'm sorry we ran out of time. Fortunately, that's not true. In fact, I would argue that this is as dangerous today as outright denial. The despair and defeatism that comes out of this unjustified view among some that it's too late to act is very disabling and arguably can lead us down the very same path of inaction as outright denial of the science itself.

So we have to recognize that it's not too late to act. There is still agency. If we reduce our carbon emissions now, we get less warming. And every additional half a degree less warming means a whole lot less bad things happen. So there is agency to what we do.

Now we published an article a couple of years ago showing that if we're to avert what many scientists would describe as truly dangerous levels of warming of the planet 2 degrees Celsius, some would argue that even 1 and 1/2 degrees Celsius. If you live in Puerto Rico, you would argue that we're already there. If you live in California, you'd argue dangerous climate change has already arrived. If you're a low lying island nation that's already facing inundation by rising seas and tropical storms, dangerous climate change has already arrived.

It's a matter of extent. It's a matter of how bad we're willing to let it get. And if we want to prevent warming of 2 degrees Celsius 3 and 1/2 Fahrenheit or more, which is when a lot of the worst sort of impacts really set in, we have to act dramatically. The talking point you've heard recently, in fact, Alexandria Ocasio Cortez was mocked for claiming that there's only 12 years left to act on this problem. But in fact, that statement was based on a finding in the most recent report of the Intergovernmental Panel on Climate Change, the IPCC, that shows that if we want to limit warming to less than a degree and a half, we have to decrease our carbon emissions now by about 10% a year for the next 10 to 12 years to keep carbon dioxide levels below what will give us more than or in this case 1 and 1/2 degrees warming.

That percentage would have been much smaller if we had acted a decade ago. If we had acted two decades ago when we already knew we had a problem, in terms of the emissions the way we have to bring them down in the years ahead, we'd be going down a bunny slope, a sort of ski slope that I can ski. Instead, we now have to go down the sort of ski slope that only my wife and 13-year-old daughter can ski, the black double diamond slope. That's what two decades of inaction has bought us, a trip down a much more perilous, much steeper decline in carbon emissions if we are to avert warming the planet beyond dangerous levels.

So there's been this assault on climate science. And you know just like the last Japanese soldier who was found a few years ago still fighting World War 2, as long as there are fossil fuels to burn, there will still be people denying that climate change is a problem. But they will become increasingly irrelevant. We will move on, but we're not there yet.

We have a president who has dismissed climate change as a hoax perpetrated by the Chinese, who thinks that a couple of cold days in the middle of winter disproves 200 years of radiative physics. We're still in the madhouse. And it's interesting, it's instructive. I've had some experiences being in the crosshairs of climate change denialists because of the so-called hockey stick curve that my colleagues and I published two decades ago, which has become sort of an icon in the climate change debate, because it tells a simple story.

You don't need to understand the somewhat complex physics of Earth's climate system to understand with this curve is telling us, that there's something unprecedented taking place with the warming that we've seen over the past century and a half and probably has to do with us. And because of that, as a physics and applied math double major at UC Berkeley, went off to Yale University to study theoretical physics, ended up doing climate science, but I didn't think I was on a career trajectory that would place me at the center of the most contentious societal debate that we've ever had. But ultimately, when we published the hockey stick, whether I liked it or not, I was now at the center of that fractious debate. And I've ultimately grown to embrace the opportunity that that's given me to inform this very important discussion about what's arguably the greatest challenge we face as a civilization.

But I've experienced some-- you know you're not supposed to laugh at this point. I haven't even told the story yet. So back in 2009, who here has heard of so-called Climategate? Yeah, just about everybody. All these stolen emails, including emails of mine that remarkably-- sort of interesting, because Russia had some role here, as did Saudi Arabia, Wikileaks, Julian Assange, stolen emails used to thwart an important political event. You might think I was talking about the last presidential election. But no, I'm talking about the affair that came to be known as Climategate back in 2009, where emails between climate scientists were stolen and put out in the public domain. Words and phrases were cherry-picked to try to make it sound like scientists were fudging the data, cooking the books.

At the time, Sarah Palin wrote an op ed in The Washington Post where she claimed that the emails reveal that leading climate experts deliberately destroyed records, manipulated data to hide the decline in global temperatures. Sounds terrible, unless you realize that what the scientists were actually talking about were bad tree ring data that they didn't want to use in a graph they were preparing because it would be misleading. And they had published an article the year before in the journal Nature describing why these tree ring data are bad after 1960 or so. It's called the divergence problem. They no longer properly track temperatures.

And so instead, they wanted to show the correct temperatures from the instrumental record that's available. And I explained that in some of the other things that Sarah Palin got wrong in my own op ed in The Washington Post that appeared nine days later. And it seems to have had an effect on Sarah Palin herself. These are her words. She said "a lot of those emails obviously weren't meant for public consumption." She admitted that. And she agreed that they could be misinterpreted if taken out of context.

Of course those were her own emails that had been released in response to a Freedom of Information Act request. And then there's the tale of James Inhofe, the senator who thinks that a snowball disproves 200 years of radiative physics, who felt that there were 17 scientists who should be prosecuted for perpetrating the hoax of human-caused climate change as revealed by these stolen emails. And I'm proud to say that I was among those 17, along with Susan Solomon, some you may know, a leading climate scientists here at MIT, recipient of the Presidential Medal of Science-- the highest honor afforded a scientist in this country. She was on that list as well.

Well, based on these stolen emails, Ken Cuccinelli-- if you know on a first name basis, his nickname is the Cooch, they call him the Cooch-- Tea Party Republican, attorney general of Virginia wanted to prosecute me and the University of Virginia based on the fact that we were perpetrating the hoax of climate change as revealed by these stolen emails. In fact, this was one of his first acts as attorney general of Virginia.

Well, The Washington Post weighed in on this five times, denouncing Ken Cuccinelli's witch hunt against me and the University of Virginia. Tom toles weighed in on this not once, but twice. I would of course later write a book with him, which is the book I'm talking about here, The Madhouse Effect. And I have to admit, I don't mind being compared to Galileo here. That comparison, that's OK. I've been called worse, trust me.

So it turns out that the case was rejected by the lower court based on a technicality. In his 40 page filing to the court, he had failed to provide evidence of wrongdoing on my part. So it was thrown out. Of course, he appealed, appealed to the state supreme court, which ultimately rejected the case with prejudice, meaning they really never want to see an attorney general come back to the court with something like this again. So is a battle was won.

He ran for governor of Virginia in the next gubernatorial election. When I was asked if I would be willing to campaign for his opponent, I was not going to decline that opportunity, because I understood the threat that Ken Cuccinelli represented to the great commonwealth of Virginia, a state that I have great affection for. And so I campaigned actively for him. Terry McAuliffe was victorious. Cuccinelli lost.

And you guys can Google this, I'm not making this up, I promise. He went off. His next venture was to help run an oyster farm on an island, Tangier Island, an island in the Chesapeake Bay that is succumbing to the effects of global sea level rise. You can't make this stuff. You can't make it up.

Well, it didn't end there. Joe Barton-- in fact, this is a few years earlier. 2005 was the case of Joe Barton who was the chair of House Energy and Commerce Committee who-- this may start to sound familiar-- wanted to subpoena all of my emails to try to discredit the hockey stick, to discredit me. And he was denounced by our leading science organizations, the American Meteorological Society, AAAS, the AGU, The journal Nature, denouncing this witch hunt, again, against a scientist whose findings might be inconvenient to the powerful fossil fuel interests who fund Joe Barton's campaigns.

It might not be a surprise to you that a progressive Democrat like Henry Waxman would have spoken out at the time against the actions of the Republican Joe Barton. But he wasn't the only one. It turns out that the heroes in this story were Republicans, were Sherwood Boehlert, who was the Republican Chair of the House Science Committee, a pro-science, pro-environment, moderate, sort of Northeastern Republican who called out Joe Barton's attacks on my colleagues and me in some of the harshest terms of anybody.

And he wasn't the only prominent Republican to do so, John McCain. And I will quote him. He wrote an op ed in The Chronicle of Higher Education, "the message sent by the Congressional committee to the three scientists-- me and my two co-authors, senior co-authors at the time-- published politically unpalatable scientific results and brace yourself for political retribution, which might include denial of the opportunity to compete for federal funds. It represents a kind of intimidation, which threatens the relationship between science and public policy. That behavior must not be tolerated."

That's the way I choose to remember John McCain. That's the John McCain that I choose to remember. And it was an act of bravery on his part, almost unprecedented in modern American politics to see somebody from one party call out another senior committee member of their own party in such harsh terms. And it's a reminder that the politics of this issue were not always so-- there wasn't so much of a partisan sort of split when it comes to basic values, like environmental preservation.

One might argue that's a conservative principle, preserving the environment. And it wasn't that long ago when this wasn't a political partisan issue. But it's become one because of powerful special interests. Now, some would say, all right, now finally, we're on to the solutions. So if we can get past the denial-- and I think there's some evidence we're doing that. We'll see that a little bit later. There's some evidence that even Republicans in the House of Representatives now want to get on to the meaningful debate about what we do about this problem and get past the fake debate about whether it exists.

So what do we do about the problem? Some say, well, why don't we just engage in some other planetary scale intervention with this system that we don't understand perfectly and hope that this other massive intervention with the climate system magically offsets the warming effect of the increasing greenhouse gas concentrations in the atmosphere? The chapter in our book, of course, is geoengineering, or what could possibly go wrong? And indeed, the principle of unintended consequences reigns supreme when it comes to geoengineering.

And the analogy I like to use is a song many of us grew up with, "There was an old lady who swallowed a fly." And she swallowed the frog to swallow the fly, and so on and so forth until ultimately she swallowed the horse. And that's what killed her, of course. And geoengineering is the horse, or may well be the horse. The cure may be worse than the ill that we're seeking to cure. We could end up with even bigger problems if we engage in these uncontrolled experiments with the only planet we know of currently in the universe that can support life. There is no Planet B.

And our former Secretary of State, Rex Tillerson, thought that that was the way to deal with climate change. Might have something to do with the fact that he was the former chairman of Exxon Mobil, the world's largest fossil fuel interest. Maybe there was a little bit of a conflict of interest there. I don't know. He's no longer our Secretary of State.

But geoengineering remains prominent in discussions about how to deal with this problem. Just this week it was back in the news. There's a new scheme that some scientists have put forward for basically sucking CO2 out of the atmosphere. And people like Bill Gates are really fond of geoengineering. And I sort of find it interesting, when it comes to techno fixes, the idea that we can use geoengineering, intervene at a planetary scale with the Earth system in some way to offset global warming-- some of the people, some of the techno-optimists who think that we can do that.

But then you say to them, well, what if instead, we were to take existing technology, like wind and solar and geothermal and scale it up? There's no way you could possibly do that. There's no way, no way we could do that. Their optimism seems somewhat selective at times.

And if that isn't the path forward, then what is? Well, arguably, it's doing something about the carbon emissions in the first place. And we've seen some evidence of progress, the Paris Agreement, which gets us almost halfway to limiting warming to below that dangerous two degrees Celsius level if all the nations of the world own up to their commitments.

Of course, President Trump has threatened to withdraw from Paris. And so we've hit this wall. And it's not the wall that you normally hear about. The true wall that Donald Trump has built is the wall that separates him from the reality of climate change, and we all will pay for it if he has his way. And as we know, he's appointed a veritable dream team of climate change denialists and delayers and fossil fuel lobbyists to run his administration. He's essentially outsourced his administration to fossil fuel interests when it comes to energy and climate policy.

Just within the past 10 days we have seen him appoint a prominent climate change denialist to a influential national security panel. We've seen him nominate a climate change denialist to be the US Ambassador to the United Nations. And just within the last week, we learned that he wants to put together a panel of climate change contrarians to discredit a report that was published by his own administration months ago, The National Climate Assessment, which establishes overwhelmingly that climate change is real, human-caused and already a problem for the United States.

And so we're still dealing with the denial. This is Tom Toles' latest, invoking executive power to declare a non-emergency, not an emergency. Climate change isn't a problem.

Well, just today, headline The Washington Post. 58 former national security officials denouncing his effort to form a climate change-denying panel because they understand what the national security community understands, that climate change-- even if you don't care about polar bears, even if you don't care about the environment-- if you care about national security, climate change is what our national security community considers the greatest threat in the years and decades ahead because it is, indeed, a threat multiplier. It takes existing tensions and exacerbates them.

So what can we do? We can push back against the denialism. And I and colleagues of mine have been active in pushing back against the policies of the current administration, the climate change denialist policies of the current administration. I was at the front of the first science march back in March 2016 with this annoying guy who was next to me wearing a bow tie. He was really annoying. Bill Nye, a good friend of mine, actually, who has sort of used his celebrity to try to bring attention to what he sees as the greatest threat that we face, the threat of climate change.

And we can all do what we can to try to make sure that we don't lose focus. We need to talk about it. We need to talk to our neighbors and our local politicians and write letters and do everything we can to make sure that this issue remains at the forefront of our politics because it is the greatest threat that we face.

And elections matter. Voting is absolutely critical. Terry McAuliffe, who you may remember I campaigned for, in return he appointed me to the Virginia Climate Advisory Board that had disappeared under the previous Republican administration. He resuscitated that commission. He appointed me to it. And when Donald Trump threatened to withdraw from The Paris Accord, Terry McAuliffe was one of the first few governors to say, we don't care what he does. I'm still in. We're still in Paris. Virginia is still in the Paris Accord.

And I talked to Terry about that. I told him I really appreciated that. And he said to me, you know, elections have consequences. And maybe it was payback for a favor done. Elections do have consequences.

So on that note, I testified two years ago to the House Science Committee, the chair of which is Lamar Smith of Texas, a climate change contrarian, a climate change denier who's actually tried to prosecute scientists, climate scientists. He's tried to defund climate science and the National Science Foundation and NOAA. He engaged in a full-on assault on climate science as the chair of the House Science Committee.

And I testified to that committee, and I just want to play one part.


- According to an article that came out a few days ago in the journal Science, Chairman Smith was on record at the Heartland Institute. This is a climate change-denying, Koch brothers-funded outlet that has a climate change denier conference every year. And Chairman Smith spoke at that conference.

- Dr. Mann, don't mischaracterize that.

- Well, let me finish.

- No, they do not say that they are deniers, and you should not say that they are, either.

- Well, we can have that discussion. I'd be happy to.

- Well, be accurate in your description.

- I stand by my statement. Can I finish my--

- I'd like to reclaim my time, Dr. Mann.

- Yes. So he indicated at this conference that he-- according to Science, and I'm quoting from them-- he sees his role in this committee as a tool to advance his political agenda rather than a forum to examine important issues facing the US research community.

As a scientist, I find that deeply disturbing.

- Dr. Mann, who said that?

- This is according to Science magazine, one of the most respected outlets when it comes to science.

- And who are they quoting?

- This is the author, Jeffrey Mervis, who wrote that article. I'd be happy to send to committee the article.

- That is not known as an objective writer or magazine.

- Well it's Science magazine.


MICHAEL MANN: So that's where we were two years ago, alternative universe where Science magazine cannot be trusted on matters of science. The bizarro world.

And where are we now? The most recent Science Committee hearing, which now has-- of course, the Democrats have won Congress. The chair of the committee is Eddie Bernice Johnson, who has stated that she wants to use her chairwomanship to give prominence to the issue of climate change and to restore the rightful role of science to our discussions about climate change.

And in the most recent hearing of the House Science Committee, the Republicans, for the first time in many years, invited mainstream witnesses who accept the science of climate change as their witnesses. They didn't invite climate change deniers. And that is a very significant development. To me, it signals that maybe we're ready to move on, to get past the bad faith debate about whether a problem exists and onto the worthy debate about what to do about it.

And perhaps, in an era where we have a Green New Deal and there's a threat of a very heavy-handed governmental approach to regulating carbon emissions, maybe Republicans have decided that they'd better get a seat at the table. If they want to have some role in the policies that we implement to solve this problem, they better get past the denial and get a seat at the adults' table, where we can discuss, because there's a meaningful debate to be had about the policy solutions. We should be debating what's the role of nuclear energy, what's the role of-- should we use a cap and trade system or a carbon tax, and if it's a carbon tax, should it be a revenue neutral carbon tax, which conservatives like?

Let's have that debate. And maybe we're ready to have that debate. So I have some optimism. Despite all of the things that have happened, and as many reasons as there might seem for despair when it comes to where we stand on climate change, I think there's some reason for cautious optimism. And not just this development, but the voice of our youth, the fact that we have these kids now who are doing these schools strikes, and the Sunrise movement. And all of a sudden there's this passion, this great passion among young people. And they speak with a moral authority that has the potential to change the whole conversation.

And so I feel like maybe we're at a juncture here, that maybe, just maybe, we're ready to start having a serious conversation about how to solve this problem. And ultimately, the stakes couldn't be greater. We literally are talking about the future of this planet, what sort of planet we want to leave behind for our children and grandchildren. So thank you very much. Happy to field any questions.


MICHAEL MANN: Please. Yeah.

AUDIENCE: Thank you very much. I just want to put a plug in for everyone, for Citizens Climate Lobby. Sorry, it's not a question. I know Dr. Mann knows about Citizens Climate Lobby. It's a national group with local chapters. There's a meeting that happens here at MIT once a month. It's pushing a revenue neutral carbon fee and dividend program. There's also bills in the Massachusetts House and Senate to enact carbon fee legislation that we should all get behind. Thank you.

MICHAEL MANN: Thanks. I get very concerned if I give a talk and nobody from CCL gets up to speak. I feel something's wrong. Please, yeah.

AUDIENCE: George Bryan. I'm a supporter of the Revolutionary Congress Party of [INAUDIBLE]. I like to tell people there is a group preparing for how to work toward getting rid of the whole capitalist framework that's put us in this predicament.

But my question to you is this contradiction between the idea of an existential crisis for humanity, which I agree, Earth in the balance-- there may be an Earth, but there may not be human beings living on the Earth any more-- the contrast between that sense, and on the other hand, this fixation on national security, which is what actually motivates the people in power in this society, Democrat and Republican.

In one stark example, we had somebody everybody loved, Barack Obama, advocating for fossil fuel expansion, including open up the Arctic to deep sea drilling, and even Hillary going up there and saying the question is not what we do, but who controls. What country controls those arctic spaces that are melting? So this great contradiction between America being an empire, essentially, competing with other empires, and that being at odds with having any kind of global cooperation because everybody is fixated on capital and expanding their capital. So how do you reconcile those two things?

MICHAEL MANN: Well, you know, I see my role in this discussion as informing the policy debate, but not prescribing the policies. And so I'm not going to stand here and say that we should Institute any particular policy prescription, cap and trade, carbon tax, what kind of carbon tax.

I would be happy if that's what we were debating, if our politicians were debating the form of the solution based on an acceptance of the objective evidence of the science, the risks that we face. And it includes national security risks, but it includes all sorts of other risks. Let's have that debate. I would be happy if that's the debate we were having in Congress. And I think that is the debate we're going to be having in Congress. Thank you for that. Please, yeah.

AUDIENCE: Hi. So thank you for your presentation. My name is Laur Hesse Fisher. I work for the Environmental Solutions Initiative here at MIT, and I'm working on expanding MIT's public engagement on climate change. In particular, I'm really interested in the conversations around climate change in red states. I was wondering if you could share a little about your experience in talking there. You mentioned Alabama. I'm curious who invited you, what the conversations were like. Was it people who had already bought into climate science, or how you manage those conversations.

MICHAEL MANN: Yeah. Well, thanks for the question. And you know, when I'm down south of the Mason-Dixon line, my southern accent sort of returns sometimes. You know, I find that wherever you go, people are not that different. And the difference between a red state and a blue state is often in the margins. And we're talking 10%, a difference of 10%, 15%.

So you can go to the deepest, darkest, reddest states. And there are still going to be people there who are very passionate about this issue, who want to do something about it. And they're often the ones who come out to these events. Sometimes you get some critics at this event. At Huntsville, it actually featured myself and a colleague of ours, John Christy, who is known as a contrarian. He's at the University of Alabama Huntsville, actually at the NASA center that's located there. And he has sort of a contrarian view about climate change.

So we sort of presented somewhat different views about what the science has to say and had a really healthy discussion, really good questions. And some of them were skeptical in nature. But I saw them as in good faith. And we need to have that dialogue. Now we're not going to win over all of the dismissives. Some of them are sort of-- their heels are dug in on this. There are people who see this no longer through the lens of science and evidence and logic, but it's ideological. You know, if you want to be a faithful member of the tribe of conservative Republicans, you're told that you-- at least have been in the past-- are told that you need to deny climate change. That's part of our identity is to deny climate change. It was written into the Republican platform, in fact.

And so some of those folks you're not going to win over. But many of them, the dismissives, the outright dismissives, people who their heels are dug in, you're not going to change their views. They're very loud, and we hear from them. There's this megaphone in the form of Fox News and The Wall Street Journal editorial pages to promote that viewpoint. But it turns out if you look at the demographics, they're like 10% of the population.

And so I think it would be a mistake for us to focus so much energy on this fringe 10% who are largely immovable when the sweet spot is this large what I call the confused middle, the people who think there's a debate because they hear the rhetoric. They're victims of the disinformation campaign. And with a little bit of information and some resources, they can be brought along. You know, you don't need 99% of the public. You don't need 90% of the public. You just need a majority of the public. At least if we can get rid of gerrymandering in Congress, just a majority of Americans, in principle, would be enough to see policy action.

So my efforts are focused on the confused middle. And wherever you go you find them in the deepest, darkest red states and in the bluest states. And so I've had good experiences in Alabama, Nebraska, Idaho, some of our reddest states. Again, wherever you go, there are good people there, and there are honest, confused people who can benefit from a good faith discussion about what the science has to say. Thanks. Please.

AUDIENCE: Thanks for the talk. I'm a student in climate science in the PhD program.


AUDIENCE: And I wanted to ask a little bit about--

MICHAEL MANN: What are you working on, if I can ask?

AUDIENCE: Ocean circulation and climate. I guess I'm wondering-- so we talked a lot about how, assuming-- sort of an easy assumption to make-- that as you increase global temperatures or increase radiative forcing, you're going to increase the damages just due to having to adapt to an increasingly hostile climate for humans. But there's another extreme, right? If we just stopped emitting fossil fuel hydrocarbons today, that would also cost a lot to civilization. We wouldn't be able to power things. There'd be a lot of human suffering, et cetera.

So you have some extreme with no climate change, and one with a lot of climate change, and presumably there's a minimum in the middle there. And do you think we have the tools to find that minimum? Or do you have any guess of what that minimum might be? And what's your view on that problem?

MICHAEL MANN: Great question. I would say just take the second derivative and-- no, I'm just kidding. It's a great question. And we don't actually know what that surface looks like. We don't even know that it has a single unique solution. All we can do is sort of work with what we know and the tools that we have.

It's pretty clear that if you try to decarbonize simply too rapidly, you are not going to be able to meet the energy demand that powers our economy. And so one can easily envision a limit where you're trying to decarbonize simply too quickly. And yet, with each additional PPM of CO2 we add to the atmosphere, we're adding to those damages.

So it sort of boils down to a discussion I actually had today with a group of climate policy folks, what is the social cost of carbon? What is the damage done by each ton of carbon that's emitted? We don't know the answer to that, in part because of things like ocean circulation. There may be tipping points in the climate system. What if we destabilize the conveyor belt ocean circulation? Or how much additional warming triggers the melting of most of the West Antarctic and Greenland ice sheet?

We don't know where those tipping points are. And if we don't know where those tipping points are, we don't know what the social cost of carbon is. We don't know what the damage has done for each incremental ton of carbon despite the fact that a Nobel Prize was given last year to somebody who basically put forward an approach for climate policy which assumes that we do know. We have some idea of what that cost is.

So I would say that we are working, then, in the domain of decision making under uncertainty. And one can appeal to the precautionary principle here. We're walking onto this minefield. We don't know where those mines are, those tipping points. But every inch that we step further onto that minefield, there's a greater probability that we trigger these tipping points. And given that uncertainty, and given that uncertainty isn't our friend, as we resolve the uncertainties, we're learning that many of the changes that we feared can happen faster, and they can be larger than we thought.

To me, that strongly weighs on the side of limiting our carbon emissions as quickly as possible. And once again, if we had started acting on this two decades ago, that would be a pretty smooth trip down this decarbonization highway. Now we've got to take a steeper trip down the highway. But the cost of inaction is already far greater than the cost of taking action, and that only becomes greater with each additional degree of warming.



AUDIENCE: Hi. My name is Alan [? Fierce. ?] I'm not a student. I'm not a scientist. I'm a retired environmental lawyer who is in a panic about where we are with the climate situation. I have a couple of grandchildren and another one on the way. I have a science question, though. Not being a scientist, and reading a little bit about you, I've learned that one of the issues you've been raising is this issue about the two degrees, or one and 1/2 degrees of warming since the advent of the Industrial Age. And as I understand it, your position is that we're not properly setting the start point for that measurement correctly, that it was, in fact, some years earlier than we originally thought.

But I'm not sure I understand that-- maybe you can explain that-- but also, the implications of that. Does that mean, for those of us who've been thinking the start date was a much later point and we had until here, we now have less time to act?

MICHAEL MANN: Yeah. Thanks for the question. It's sort of an example of the lamplight effect. You know, you lose your keys, you look near the lamp light because that's the only place you're able to see. That's the way that the IPCC has decided to define the pre-industrial because the instrumental record of temperatures, global temperatures, only goes back to the mid- to late 19th century. And so for convenience, they've said well, we'll use the late 19th century average as our estimate of the pre-industrial.

But all you have to do is run a climate model simulation with the actual historical changes in CO2 to see that we had probably warmed between 0.1 degrees Celsius to 0.2 degrees Celsius before that point. So the true pre-industrial state is probably 0.1 to 0.2 degrees Celsius, smaller, lower than the baseline that's used by the IPCC.

Now that might sound like a small difference, but it turns out that we're at about 1.2 degrees. We're close to 1.2 degrees Celsius warming now. If we're going to limit warming to 1.5 degrees Celsius, we've got a very small amount of wiggle room. In fact, part of the problem is if we stop burning fossil fuels, if we stop burning coal, we stop putting particles into the atmosphere that actually cool certain regions-- and in particular China, which is still engaged in dirty coal burning, has produced a fair amount of sulfur dioxide that leads to these so-called aerosols that have a cooling effect. So we'll probably get another 0.1 or 0.2 degrees of warming if we stop burning fossil fuels just from the disappearing aerosols.

Then we're up there already at about 1.5. So we have almost no room, no margin for error if we're going to avoid one and 1/2. What we calculated, we didn't look at the one and 1/2 limit. We looked at two degrees Celsius. What does that difference of as much as 0.2 degrees Celsius of additional warming mean? It turns out it means that our budget-- how much carbon we can still burn and remain below two degrees Celsius-- is up to 40% less than the IPCC concluded.

So we have to decarbonize even faster, underscoring the fact that the IPCC is a conservative body. Despite the fact that it's often dismissed as alarmist, if anything, the IPCC-- which is a lowest common denominator of thousands of scientists-- by its nature, tends to be a conservative assessment. If anything, the IPCC is overly conservative in that regard.

So now there's another footnote here. Then you can ask, well, what do we really mean when we define the danger? When we said two degrees Celsius was dangerous, did we mean relative to the true pre-industrial, or relative to the definition that we've been using of the pre-industrial of the late 1800s?

And it turns out the answer is a bit mixed. In some cases, the impacts are assessed based on running a control simulation with CO2 levels at 280 parts per million. That's a true pre-industrial. If we've defined an impact based on the use of a true control simulation, than we mean pre-industrial. And we do have to add on that additional warming to assess how much we've warmed. In some cases, it's defined a little differently.

So it's a little muddy. But the bottom line is, if anything, the IPCC's assessment is overly conservative, and arguably we have to decarbonize even faster to avoid those thresholds.


MICHAEL MANN: What's that?

AUDIENCE: How do you arrive at the 0.1%?

MICHAEL MANN: 0.1 to 0.2 degrees Celsius. That's based on using climate model simulations. There's a suite of climate model simulations that have been run for the past 1,000 years. It's part of the IPCC assessment process. So we've got these climate models we can use to estimate how much warming was there due to the increase? The CO2 started increasing in about 1700. You can see the Industrial Revolution back to about 1700. And it turns out the early rise has a proportionately greater effect on temperature because of the logarithmic nature of the relationship between CO2 and temperature.

AUDIENCE: Yeah. Great talk again. I'm Jeff Ackley with the EcoEnlightened Charitable Organization.

MICHAEL MANN: I saw you yesterday, didn't I?

AUDIENCE: Yes. And I actually have a follow-up question from yesterday which you didn't address today. I was hopping you'd talk a little bit about it.

MICHAEL MANN: Uh oh. All right, he's chased me down. OK, yes.

AUDIENCE: So as you know, the EcoEnlightened Charitable Organization is focused on getting people to think differently about climate change, and more positively, and take positive action. And I'm concerned with what I would call sort of the new denier, and what's going on with this new denial, and specifically Lomborg and what he's focused on. And I heard him talk-- matter of fact, I sat next to him. Very convincing and intelligent person. And I was wondering if you'd just talk a little bit about him, what he's trying to do in that new denial.

MICHAEL MANN: Yeah, so I call this the kinder, gentler form of denialism. And I do think it's a threat. It's denialism that wears a Greenpeace t-shirt to convince you that it's environmentally aware. And Bjorn Lomborg does wear a Greenpeace t-shirt. He's funded--

AUDIENCE: He's not authorized by Greenpeace.

MICHAEL MANN: Unfortunately, they don't get to regulate who can wear the t-shirts.


MICHAEL MANN: Yeah, absolutely. He's using that to somehow convince you that he has the imprimatur of the environmental organizations, and he doesn't, of course. And he's very smooth. And what he does is he will claim to accept the science, but in fact, he doesn't, because he will downplay the projections. He will dismiss many of the impacts.

In fact, there's a very famous case where he pointed to the sea level record, which is increasing steadily, but because of things like El Nino events, you get little wiggles. Sometimes sea level goes down a little bit because you've got a lot of rainfall over Australia during an El Nino year. And so the ocean loses some of that water. It's stored over the land. And you can get a little down dip in sea level on a time scale of a year or so.

And what he did was point to one of those little down dips. And he actually said, look, sea level has gone down. Why don't we hear this good news? El Nino is good news, apparently, when it comes to climate change. Well, you know, you get the flip side, then, La Nina, where it actually goes up even faster.

So it's misleading. It's misrepresenting the data. So in a sense it is denying the science, or it's misrepresenting the science, and using that misrepresentation to downplay the impacts and the cost of inaction. And then he'll do something like he'll use a very high discount rate. So one of the things that's done in climate cost benefit analysis is financial discounting because $1.00 10 years from now isn't worth as much as $1.00 today. You lose the opportunity to spend that dollar.

And so the idea is that impacts that occur in the future are downweighted relative to current impacts. And if you downweight it fast enough with a large enough percentage, then the mathematics will tell you that there's no reason to act, that the financial impact will be minimal. Well, it turns out that the quality of life of our children and grandchildren isn't like a 30 year Treasury bond. We don't downweight the quality of life of future generations.

And so an argument has been made that you shouldn't do that. And if you do do it, it shouldn't be the 7& or 6% that Bjorn Loomborg uses. It should be what Bill Nordhaus, who won the Nobel Prize for developing this approach to climate policy, has said, that probably 3% is the maximum rate that it makes sense to use. So it's a way of systematically downplaying the problem, but claiming to accept the science, which gives you sort of the imprimatur of being reasonable.

And because it's so difficult now, with the impacts of climate change playing out so prominently, it's so difficult to dismiss the fact that climate change is happening because people can see it with their own two eyes. We see what's happening.

So it's no longer useful for fossil fuel interests to employ talking heads who deny the science, deny that it's happening, because that's not credible. But people like Bjorn Lomborg, who say well, no, I accept the science. It's happening, but the impacts aren't too bad. And by the way, if we act on this problem, it'll destroy the economy-- which I would call alarmist rhetoric, by the way-- that's the true alarmist rhetoric. They are as much a threat today as those who outright deny the science. And they are denying the science in the sense that they're mischaracterizing it, and they're mischaracterizing the impacts and presenting a misleading view of the cost of inaction.

If you're interested, I went up against Bjorn Lomborg in a Huffington Post Live Earth Day panel discussion forum years ago. You can find it online. And I had the delightful opportunity to call these things out in real time during the course of our discussion because he was sort of throwing-- you know, doing the usual cherry picking. And it became very obvious to any viewer, I think.


MICHAEL MANN: Well, there's the famous quote. Upton Sinclair. You've all heard it before. Very difficult to get a man to understand something when his salary depends on him not understanding it. It might have something to do with the thousands of dollars he's gotten from the Koch brothers, maybe. I don't know. Maybe. Please.

AUDIENCE: Hi. I'm Mara Frelich. I'm also a PhD student here in climate science. So thank you for the talk. . I had a question, I guess, more about your personal path. And so I think you're extraordinary among a lot of your colleagues in having seized the opportunity that pretty much anybody in climate science has to become engaged in the political aspects of this work.

Yeah, so two questions there. One is what allowed you to make that choice in the moment of making the choice, and then continually making that choice as you go about your life. And then the second is what do you think graduate students or young climate scientists need in their education in order to effectively engage with the political aspects of our work?

MICHAEL MANN: Thanks for the questions. Good questions. So I didn't really have a choice. When we published the hockey stick and it became this icon, I found myself in the cross-hairs. I found myself under the spotlight, in the public sphere whether I liked it or not. It was the last thing. It was not what I had chosen. It's not why I decided to double major in applied math and physics. I didn't think that's where it was going to be leading me.

But with the publication of the hockey stick, I found myself in that place. And my instinct was to defend myself against what I felt were invalid attacks against my science and attacks on me. And ultimately, it sort of opened my eyes to the fact that there are larger things at stake here. This isn't just about me and defending my work. It's about the science here has implications, like I said before, the greatest societal challenge that we face.

And here you have these bad actors who stand to profit from leading us down a disastrous path for humanity. And even though it's not what I had signed up for, I ultimately embraced the role as a public figure in this debate because I had this opportunity to try to influence this conversation, like I said before, about the greatest challenge we have.

And I've embraced that. And it's led me down a completely different path from the one that I had chosen initially and intended. I'm still able to do some science, and that's really important to me because my first love is doing science. That's why I went into this. I love solving problems, cranking, constructing models, crunching numbers. That's still my bread and butter. It's still what I love doing. But I have this opportunity now to play this other role. And I feel privileged to be in a position to do that.

What I would say for younger scientists today is that in the sense, it's much easier-- the path towards engagement with the public, for your generation, is easier because it's a natural extension of the way people grow up. In the world of social media, people engage with the public as a natural extension of their daily lives. And what I find is that young folks, it's far more natural to them to participate in the public discourse, and they're far more skilled at doing so.

And we need a diverse set of voices that speaks to the diversity of society overall. I'm still part of a generation where most of the talking heads are white males. And we live in a diverse society, and we need far more representation from people with diverse backgrounds, diverse with respect to ethnicity and gender and everything else.

And one of the things that I'm delighted in is the fact that we are seeing a far more diverse community of scientists who are coming up now and choosing to engage in public outreach, not because they were forced into it like I was, but because they choose to do so, because they have a passion to do so. I actually think that to some extent, the attacks on our science has helped create this new breed of scientists that's very passionate about defending science and about ensuring that the public get an objective view of what science has to say.

So if you're interested in outreach and communication, there are now so many opportunities to do so. Obviously, social media is an easy way to do it. But for people who have an interest and a proclivity for communication, there are now lots of opportunities. It's now recognized in a way that it wasn't in the past. It used to be that if you spent time doing communication, it would hurt you professionally. You would be seen by your colleagues as not being a serious scientist. The Carl Sagan phenomenon. Carl Sagan suffered, to some extent, professionally because of his choice to be a science communicator and popularizer.

I think the culture of science is very different today. It rewards those choices. And so I would say if you like doing it and you enjoy doing it, there is no end to the opportunities that are available to participate in the larger conversation.


MICHAEL MANN: Again, there's no longer the obstacle to participating in the public discourse that there used to be. Anybody can go on social media, go on Twitter, what have you, Facebook. And you can write letters to the editor. You can talk to your friends and family and church members and schoolmates and your work colleagues.

Again, there's no limit to the ways anybody can participate in this discussion. And it's really important because if people aren't talking about this problem, if ordinary people-- not just the scientists-- ordinary people aren't talking about this and forcing the issue into our daily conversations, it's too easy for politicians to ignore it.

But they can't ignore the voice of the people. We've seen that in recent years. If there's an overwhelming demand by the public to act on something, politicians find it unavoidable to fail to act. And so we can all play a role, every single one of us. Thanks.

AUDIENCE: Hello. I'm a high school senior, and I've really enjoyed this event. I have two very similar related questions. You mentioned a bit earlier about Virginia's push to stay in the climate accord even though Trump is pulling out. Do you think that it's possible that if enough municipalities and local governments commit to the accord, the US as a whole could still fulfill its commitment? And just in general, do you think that long-lasting climate change policy is tenable or possible with-- at least in the US, we tend to ping pong from one view set to the other every few years or so.

MICHAEL MANN: Thanks. Yeah, good questions. You know, the political cycle can make it difficult to have some coordinated long-term strategy for acting on a problem like climate change when you get a new administration comes in, tries to change all of the executive policies, tries to undo-- as we're seeing right now-- all of the progress that was made under the previous administration.

And yet some of the changes become institutionalized. They become sort of ingrained into our economy. There are structural changes that are taking place today that are moving us inevitably away from fossil fuels. And nothing that Donald Trump claims he can do or wants to do is going to prevent the coal industry from disappearing. They're just not going to be competitive in the marketplace against newer energy technologies, including renewable energy.

So it's inevitable. That's the direction the rest of the world is moving. That's the great revolution of this century is the clean energy revolution. And those countries that choose to get on board are the ones who are going to prosper in that economic race, if you will. So we don't get to choose. The United States, Donald Trump, doesn't get to choose whether or not we act on climate. The world is acting. The world will act on climate. All he gets to choose is whether we at least temporarily get left behind and we allow China and all the other countries of the world to outcompete us in the global economic race.

So we're seeing steady increases in the market share of renewable energy in the United States, electric vehicles. We're moving in that direction. We have 30% of the population in the US-- even in the absence of any federal executive policies on climate under this administration, and even in the absence of congressional climate legislation. We don't have that either.

But just based on the fact that many states are acting and are banding together to form consortia. Massachusetts is part of Reggie, the Northeastern consortium. New Jersey and Maryland have joined, have come on board. Pennsylvania, we're hoping, will become part of that coalition as well. You've got the west coast states that have formed a coalition. 30% of the population lives in a state that's part of a regional consortium for pricing carbon.

So we're moving in that direction. Nothing's going to stop that. And it's just a matter of whether or not we're going to keep up with the rest of the world. And as I said in this talk, elections have consequences. We have a say. And what we saw in this last election is that if you look at the change in the complexion of the House of Representatives now when it comes to the issue of climate, where even Republicans are no longer really contesting the science. They're just trying to make sure that their preferred policies are at the table.

That's a huge shift, and it's a shift because people turned out to elect politicians who would stand up for their interests rather than the polluting interests. And if we continue to do that, then we will continue to see progress. But we have to vote. We have to come out and vote in elections. If we don't do that, we've seen the consequences of that, too. Thanks.

Final question. Thanks.

AUDIENCE: Thank you. I'm not a climate scientist, but I am a social scientist and a historian. And I must say that I don't fully share your sense of optimism in this regard, in part because the lessons of both history and social science are that people under stress don't act on what they know. They act on what they believe.

And in this respect we're in real trouble because some of the things that you've asserted that we are about to manifest in our beliefs, new leadership and the like, is still predicated on the economics of continuous growth, on the techno scientific salvationism that somebody is going to pull some rabbit out of some hat and we're going to be able to adjust, all the while expanding as a human population on a finite planet. It's a nonstarter for any ecologist. The question is how do you get to sustainability, not the oxymoron of sustainable growth? Can't happen. Won't happen.

MICHAEL MANN: So thanks for the question. So climate change is just one dimension in this multi-dimensional problem that is environmental sustainability. And even if we solve the climate problem, there's still overfishing. There's still the pollution of our oceans and atmosphere. There is still the loss of biodiversity deforestation the list goes on.

This is a multi-dimensional space. And so my discussion has focused on one problem. But I am not denying that that is just a subset of a larger number of problems that we face, which is the crisis of living sustainably on a planet with finite resources. And by some estimates, we have leveraged this planet through technology that we're highly dependent on to a population that might be seven times larger than the natural carrying capacity of the planet.

And if that's true, that means that we could potentially be in for a collapse. If we're so dependent on technology to , allow for that inflation of the carrying capacity of the planet that means that any collapse in infrastructure could lead to a collapse in population and a fundamental change in the nature of human civilization.

I don't question that that's a possibility. And what it underscores is the fact that prevailing on the climate issue isn't enough. There are a lot of problems that we face. It's not even clear that climate change is the greatest crisis that we actually face.

And so I don't purport, I don't pretend to be speaking-- I'm not the Lorax-- I'm not speaking for the trees. I'm not speaking for all of the problems that we face. I'm just talking about one. And I would advise people to recognize that the challenge we face is even larger.