Making Sense - Sam Harris - #95 — What You Need to Know About Climate Change

00:00:00.000 Welcome to the Making Sense Podcast.

00:00:08.820 This is Sam Harris.

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00:00:46.420 My guest today is Joseph Rome.

00:00:49.300 Joe is one of the country's most influential communicators on climate science and solutions.

00:00:53.500 He was chief science advisor for the show Years of Living Dangerously, which won the 2014

00:01:00.480 Emmy Award for Outstanding Nonfiction Series.

00:01:04.060 He is the founding editor of Climate Progress, which Tom Friedman of the New York Times called

00:01:09.500 the Indispensable Blog.

00:01:11.920 In 2009, Time named him one of the heroes of the environment, and Rolling Stone put him

00:01:17.920 on his list of 100 people who are, quote, reinventing America.

00:01:22.460 Rome was acting assistant secretary of energy in 1997, and he's a fellow at American Progress

00:01:29.120 and holds a PhD in physics from MIT.

00:01:33.420 And perhaps most relevant, he is the author of Climate Change, What Everyone Needs to Know,

00:01:39.380 put out by Oxford University Press.

00:01:41.100 And it is a very handy, accessible, comprehensive book that is organized in Q&A format.

00:01:48.900 So every question you have ever had or heard posed, skeptical or otherwise, about climate

00:01:54.620 change seems to be answered in this book.

00:01:57.780 And Joe and I get into many of the details.

00:01:59.840 We talk about how we know the climate is changing and how we know that human behavior is the primary

00:02:04.480 cause.

00:02:04.940 We talk about feedback mechanisms that increase the problem of global warming and why small

00:02:11.520 changes in temperature matter so much.

00:02:14.400 We talk about the threats of sea level rise and desertification and the best and worst case

00:02:21.280 scenarios given where we currently are.

00:02:24.060 We talk about the much maligned Paris Climate Agreement and the politics surrounding climate

00:02:30.940 science.

00:02:31.380 And now, without further delay, I bring you Joe Rome.

00:02:42.040 I am here with Joe Rome.

00:02:43.860 Joe, thanks for coming on the podcast.

00:02:45.640 Thanks for having me, Stan.

00:02:47.200 We're going to talk about climate change, which, as you know, is a big and important topic.

00:02:52.320 And we will talk about what we know about it, what we don't know about it.

00:02:57.460 And I suppose what many people refuse to know about it.

00:03:02.200 But first, before we jump in, can you describe your background scientifically and in policy

00:03:09.180 circles and just the work you've done on this issue?

00:03:12.080 Sure.

00:03:12.800 Well, I have a PhD in physics for my T.

00:03:16.500 And I spent a year on Capitol Hill as a Congressional Science Fellow.

00:03:25.560 And then I went to work at the Rockefeller Foundation for a couple of years looking at

00:03:33.100 issues like the environment and national security and energy.

00:03:37.560 And I worked with Amory Lovins for a couple of years, the father of energy efficiency, really

00:03:44.780 a great guy.

00:03:46.140 And then five years at the U.S. Department of Energy during the Clinton administration, where

00:03:51.600 I ended up acting Assistant Secretary for Energy Efficiency and Renewable Energy, which is the

00:03:57.760 billion dollar office that does all the clean energy research, development, demonstration

00:04:03.000 programs for the federal government.

00:04:07.680 And then I left to do a lot of consulting with companies on how to reduce greenhouse gas

00:04:13.120 emissions and how to use efficiency and renewables.

00:04:16.500 And then August 29, 2005, Hurricane Katrina destroyed my brother's home.

00:04:24.840 He lives in Paschristian, Mississippi, and a mile inland, there was, you know, a 20-foot

00:04:33.140 storm surge, and the inside of the house looked like a washing machine.

00:04:36.340 He asked me if he should rebuild his home.

00:04:39.200 And I started talking to climate scientists and hurricane experts and reading the literature

00:04:46.880 and going to conferences.

00:04:48.360 And that's when I realized that two things, climate change was a lot more dire than I

00:04:55.980 realized, and that scientists weren't doing a very good job of communicating it.

00:05:02.680 And since I had been raised by newspaper people, my father's a newspaper editor, I decided to

00:05:11.960 stop doing clean energy consulting and just do writing and communications on climate change.

00:05:16.760 And I was able to get a position at the Center for American Progress, which had recently started

00:05:22.940 and launched its ThinkProgress website, which is one of the most widely read news, progressive

00:05:32.260 news websites in the world.

00:05:35.800 And that was about 11 years ago, 11 years ago next week.

00:05:40.060 I launched climateprogress.org, which grew over time into a, you know, we now have a staff

00:05:55.040 of five or six reporters.

00:05:57.780 It's part of the larger ThinkProgress enterprise.

00:06:02.700 If you go to ThinkProgress, you'll see articles by me and other people on clean energy and climate

00:06:09.160 change.

00:06:10.160 And it's probably the most widely read climate website in the world.

00:06:16.380 And that's what I've been doing for 11 years.

00:06:20.960 I also worked with the Years of Living Dangerously TV series.

00:06:24.700 Some of you may have seen on Showtime a few years ago or last year on National Geographic

00:06:31.920 Channel, that's the James Cameron, Arnold Schwarzenegger series, Emmy-winning series that documents

00:06:41.980 what's going on on climate change, what the solutions are.

00:06:47.060 And so that's what I've been doing.

00:06:49.100 You know, I'm very fortunate to, you know, be able to keep track of climate change and clean

00:06:55.880 energy and write about it and speak about it.

00:06:57.980 Yeah, and you've written this very lucid book that's right on point, titled Climate

00:07:04.160 Change, What Everyone Needs to Know, published by Oxford University Press, which is not actually

00:07:09.440 known for publishing propaganda.

00:07:12.220 And if I'm not mistaken, your PhD in physics from MIT was not focused in some totally unrelated

00:07:20.420 area.

00:07:21.400 Didn't you have some focus on oceanography?

00:07:23.780 It did focus on oceanography.

00:07:26.020 Yeah, I was fortunate.

00:07:28.040 I was able to do my PhD thesis with a man named Kostad Zepes, who back in the day, you know,

00:07:37.660 wrote a great number of scientific American pieces, particularly on arms control issues.

00:07:44.580 And he allowed me to do my thesis research at the Scripps Institution of Oceanography with

00:07:53.980 Walter Monk, one of the world's greatest oceanographers, and actually did my thesis.

00:08:00.320 It wasn't on climate change at all, but the thesis itself was an analysis of data from the

00:08:06.620 Greenland Sea, and, you know, just being at Scripps and attending seminars by some of the

00:08:15.220 world's greatest oceanographers, you know, I couldn't help.

00:08:19.440 But also learned at the time, this was the mid-1980s, before a lot of people were talking

00:08:26.300 about climate change, they were talking about climate change.

00:08:28.960 So that was a true education.

00:08:32.340 Right, right.

00:08:34.100 So before we jump into the details here, I should say that my goal in this conversation

00:08:39.540 is to dispel the most consequential forms of confusion on this topic.

00:08:45.460 And so I went out on Twitter when I knew we were going to do this interview, and I announced

00:08:50.720 that I'd be doing a podcast on climate change, and I asked people to post questions.

00:08:53.860 And I got over 1,000 responses, so there's no shortage of questions here.

00:08:58.960 But let's start with the basic picture of what's going on.

00:09:03.000 And I want to get into the weeds, but I don't want us to assume that people know much of anything

00:09:09.100 about this issue, because despite its enormous importance, most people, certainly many people,

00:09:15.680 don't.

00:09:16.280 So first, what is the difference between climate and weather?

00:09:19.280 Well, weather, climate, they say, is what you expect, and weather is what you get.

00:09:26.500 So weather is highly variable day to day.

00:09:30.080 Is it going to be cloudy?

00:09:31.520 Is it going to rain?

00:09:32.700 Is it going to be a very hot day?

00:09:34.640 Is it going to be a coolish day?

00:09:37.580 That's the weather.

00:09:39.640 But of course, on a given day, whether it's warm or cold is relative to what the underlying

00:09:45.740 climate is.

00:09:46.520 A hot day in the summer is obviously quite different than a hot day in the winter.

00:09:51.480 So weather forecasting is obviously tricky, hard to do more than a week, 10 days in advance.

00:09:58.340 But climate is the statistical aggregation of all the weather.

00:10:02.900 So climate tells you it's going to be warmer in the summer.

00:10:06.640 Climate tells you the Greenland is going to be colder than the Sahara Desert, and the Sahara

00:10:11.940 Desert is going to be drier.

00:10:13.420 So the long-term trends in your local climate are very slow moving.

00:10:23.820 And one of the points that I make in the book and on the website is that since we came out

00:10:30.960 of the last ice age 11,000 years ago, the Earth's climate has been very stable.

00:10:36.360 And the temperature has really varied over maybe half a degree Fahrenheit, plus or minus.

00:10:44.240 And that stable climate is what allowed people to settle in cities.

00:10:50.580 They had reliable...

00:10:52.680 The weather wasn't constantly changing.

00:10:55.180 They knew what the rainfall would be.

00:10:56.760 They knew what sea levels would be.

00:10:59.320 People, therefore, could have large-scale agriculture.

00:11:03.280 And that led to cities.

00:11:04.420 And that has sustained now a population of over 8 billion people.

00:11:09.020 But, you know, because we have been pouring vast amounts of heat-trapping greenhouse gases into

00:11:17.900 the atmosphere, we have seen a rapid rise in temperature, particularly over the last century

00:11:25.820 or so.

00:11:27.000 So when, in fact, the temperature of the Earth driven by greenhouse gases, driven by burning

00:11:35.060 fossil fuels, coal oil and gas, and releasing carbon dioxide, that temperature change has

00:11:40.940 been 50 times faster than the very slow changes in the past 5,000 years.

00:11:47.660 And it is both the amount of change and the speed that's worrisome, because the faster

00:11:54.160 it changes, the, you know, the harder it is to adapt to.

00:11:57.420 And the more it changes, of course, the more dramatic the impacts are.

00:12:02.060 We've already closed the door to one source of skepticism here about climate change, because

00:12:06.660 most people understand that it's impossible to predict the weather far in advance.

00:12:11.960 And from that, they conclude that it must be hard to say anything about the climate far in

00:12:17.280 the future.

00:12:18.140 In fact, we got one of these on Twitter.

00:12:20.440 One person wrote, most forecasts can't accurately predict the weather more than five days in

00:12:24.480 advance.

00:12:25.400 How can you have it right for five years or five decades ahead?

00:12:29.020 So we spared one person some fatal embarrassment.

00:12:31.820 I think that is a very important point worth driving home.

00:12:36.260 I can't tell you in one year whether you're going to have, you know, a 100-degree Fahrenheit

00:12:45.020 day or a 60-degree Fahrenheit day.

00:12:48.820 But I, you know, I do know what the average yearly temperature is.

00:12:53.460 And if you look at the average yearly temperature of the globe or even the average monthly temperature,

00:12:59.120 that doesn't change very much over time.

00:13:03.320 Unless, of course, something is forcing it to change.

00:13:06.140 That's the key point.

00:13:07.140 We're forcing the change.

00:13:09.240 And that's why, year by year, we've been seeing these hotter and hotter years.

00:13:15.280 Okay.

00:13:15.440 So tell me how we know that we are forcing this change.

00:13:20.320 There's two parts here.

00:13:21.340 How we know that the climate is changing, i.e. heating up, and how we know that humanity

00:13:29.500 is playing a role in changing it.

00:13:31.840 And for this part, I'd really like you to limit yourself to what is totally uncontroversial

00:13:37.940 from a scientific point of view.

00:13:39.320 And we can get into gray areas later.

00:13:41.480 But is there a version of this story that is at the level of smoking is harmful to your

00:13:48.820 health?

00:13:49.380 Can we make it that uncontroversial?

00:13:52.560 Sure.

00:13:53.180 Although that still won't make it uncontroversial in the sense that, as you know, the tobacco

00:13:58.220 companies launched a major disinformation campaign to confuse the public for decades about the

00:14:05.600 science of smoking and the health consequences.

00:14:10.280 And so, you know, decades after the medical community, you know, was quite certain that

00:14:16.700 smoking was bad for your health, that myth persisted.

00:14:21.020 But it is true, and, you know, in recent years, the scientific community has said that our

00:14:27.200 certainty that the climate is changing, that humans are the primary cause, our certainty

00:14:33.800 level is exactly comparable to our certainty level that cigarette smoking is bad for your

00:14:38.560 health.

00:14:38.940 So they are comparable.

00:14:41.760 One thing I want to say right away, and I'll probably repeat.

00:14:45.060 Anybody who wants to know the underlying science of these myths and the debunking of them, there's

00:14:53.900 a website, a great website, which just had its 10th year anniversary called Skeptical Science.

00:15:00.500 And it literally goes through each of these.

00:15:05.820 And you can click on links to the actual scientific literature, depending on how informed you want

00:15:11.360 to get.

00:15:11.660 So fundamentally, if you look over the history of the Earth, whenever the climate changes

00:15:20.940 substantially, it's because it was forced to by some external change.

00:15:26.780 Often that change was a slow change in the Earth's orbit, reducing the amount of sunlight

00:15:34.120 that hit particularly the northern hemisphere.

00:15:36.940 And that led to the ice age cycle, you know, over the past million plus years.

00:15:44.800 But those ice ages and the end of those ice ages, as it turns out, were triggered by the

00:15:51.520 changes in the Earth's orbit.

00:15:52.680 But those changes then actually led to a feedback, which is release of greenhouse gases and other

00:15:58.020 feedback.

00:15:58.420 So we have known literally for two centuries that there are certain gases that trap heat

00:16:07.380 in the atmosphere.

00:16:08.580 And that the major one, the major one that we control is carbon dioxide and that it has

00:16:17.760 been predicted.

00:16:18.540 It was predicted for over a century that if you keep burning, you know, the fossil fuels

00:16:26.280 that have been tracked in the ground in the form of coal, oil and gas, if you keep burning

00:16:32.120 those, you are going to be basically putting more and more blankets around the Earth.

00:16:38.140 You're going to be heating up the Earth.

00:16:39.980 And that heating up is going to have a whole bunch of consequences.

00:16:45.680 As to the question of how do we know that humans are the major cause, the answer is twofold.

00:16:52.200 One, you can look at all of the potential sources of heating and cooling.

00:16:56.920 And you find, particularly in recent decades, that all of the ones that aren't human-caused

00:17:06.820 would actually be cooling the Earth because the sun's, you know, solar radiation has actually

00:17:13.560 declined slightly in recent decades.

00:17:16.820 We've had volcanoes.

00:17:18.460 They're another cooler because they put in aerosols that block the sun.

00:17:22.800 And so if you take away all of the so-called natural cycles and natural things that change

00:17:33.800 the climate, you would find that the vast majority of warming since the middle last century is

00:17:44.900 due to human activity, principally the release of these heat-trapping gases.

00:17:50.500 And in fact, not only did the scientific community conclude in its most recent assessment, every

00:17:58.520 five years, all the world's leading scientists review all the scientific literature and they

00:18:04.240 issue reports to the world government.

00:18:06.380 Those are the Intergovernmental Panel on Climate Change.

00:18:08.800 And those reports, by the way, are literally argued over line by line by all of the governments

00:18:15.340 of the world.

00:18:16.080 So they end up as the least common denominator.

00:18:20.740 And that, those studies, the most recent one concluded two things.

00:18:25.420 There is a 95 to 100% chance that most of the recent warming is due to humans.

00:18:34.340 And at the same time, the best estimate for how much of recent warming is due to humans is

00:18:43.640 all of it, 100%.

00:18:45.420 So the peak in the most likely scenario is that humans are responsible for all of the

00:18:52.300 warming since 1950.

00:18:54.180 But, you know, like a, you know, you envision a, you know, a curve, like a bell curve, you

00:19:02.880 know, there are small chances that all humans are only responsible for, let's say, 75%.

00:19:09.980 But, you know, there's no point in getting into a lot of detail on that because this is not

00:19:14.980 a subject of much debate at all in the side of the community.

00:19:19.640 I'm actually wondering whether it's relevant in the end.

00:19:23.060 So there are at least three parts to this story.

00:19:26.420 There's the fact that the planet has been warming over the last century.

00:19:29.580 There's the fact, or at least the claim, that human behavior has contributed to it, either

00:19:36.660 in part or in entirety.

00:19:39.160 And then there's the claim that warming past a certain point would be catastrophic for us.

00:19:44.840 And we will definitely get into that.

00:19:47.300 But this third claim, in my view, seems to undercut the significance of the second.

00:19:52.660 I mean, if warming past a certain point is going to be catastrophic for us, it doesn't

00:19:58.080 much matter who caused it, right, or what the cause is.

00:20:01.820 We'd want to find some way of mitigating this warming, arresting it and mitigating it anyway,

00:20:07.180 right?

00:20:08.020 Well, I don't entirely agree with that in the following sense.

00:20:13.440 Knowing that humans are the major cause tells us we are the major solution.

00:20:20.200 If this were just an underlying natural change, like the incredibly slow changes in and out

00:20:28.200 of the ice ages, then, you know, there's not much we could do.

00:20:33.260 I mean, we could adapt.

00:20:34.440 We could plan for the changes, but we couldn't stop the changes.

00:20:40.100 The fact that we know that we are, you know, essentially all of the cause of recent warming

00:20:45.420 tells us that if we were to change, you know, replace fossil fuel combustion with, you know,

00:20:53.300 clean energy, renewables and the like, that we would slow and ultimately stop the amount

00:21:00.780 of warming.

00:21:01.820 And so that's sort of point one.

00:21:04.840 Point two...

00:21:06.060 Joe, let me just jump in there. 0.88

00:21:06.860 I totally agree with that in that it points to a way forward toward a solution.

00:21:11.000 But given the predicted consequences here, a sudden warming, not a gradual warming, would

00:21:18.080 be bad for us, whether or not we're the cause.

00:21:21.500 And if there's any way to mitigate it, we would be interested in doing that.

00:21:25.900 I guess what I'm trying to do here is differentiate the problem as we face it from a kind of common

00:21:33.080 attitude you find among people, which is just a matter of disapproving of human-caused change

00:21:39.640 in principle, analogous to thinking that it was a bad thing that we wiped out the dodo

00:21:44.600 bird.

00:21:45.180 There's a kind of a sentimentality for nature that I don't want us to be confused by.

00:21:52.140 I'm not saying I don't share it, but that's not really the issue.

00:21:55.960 The issue is if the average temperature of the planet keeps going up and we hit the most

00:22:01.640 dire projections, whatever the cause, we have a huge problem for which we should be seeking

00:22:09.020 a solution.

00:22:09.860 Right.

00:22:10.440 But let me, if one thing I can get out of this discussion with you is to persuade you

00:22:16.660 that the phrase whatever the cause is really a phrase that concedes the battle and it is

00:22:27.800 false.

00:22:28.360 It's wrong.

00:22:28.900 It isn't whatever the cause.

00:22:30.240 If we didn't know the cause, then we wouldn't know that warming is not only going to continue,

00:22:36.520 it's going to speed up.

00:22:38.900 Right.

00:22:39.460 We're not, this is science.

00:22:41.340 You know, we put 12 men on the moon and we got them back.

00:22:43.840 We don't make guesses.

00:22:45.780 And the scientific community as a whole doesn't come out and say, you know, on our current

00:22:51.120 path of burning fossil fuels, we are headed towards rates of warming that will have catastrophic

00:22:57.000 impacts.

00:22:58.160 If you took away the cause, then you'd be able to make no statements about the future.

00:23:04.120 At the end of the day, what science is, is an ability to make testable predictions.

00:23:13.620 And if your predictions don't come true, you know your theory is wrong.

00:23:17.040 And if they do come true, then you have growing confidence in that theory.

00:23:21.220 So, no, I don't use the phrase whatever the cause, because we know the cause.

00:23:26.120 And that's how we know what's going to happen.

00:23:30.280 And that's why we know it's going to happen literally, you know, thousands of times faster

00:23:37.740 than whenever the climate change, you know, because of purely, you know, orbital or natural

00:23:44.660 changes.

00:23:46.120 And we are, in fact, acidifying the oceans, you know, more than 10 times faster than ever

00:23:54.120 happened before under, you know, previous, you know, dating back millions and millions

00:23:59.440 of years.

00:24:00.840 Can I make one other point, which I'm not going to go into, but you can read my book.

00:24:04.840 The, the, there are also, the type of warming that we're getting is also, um, uh, the exact

00:24:15.840 type of warming that you would expect if it were due to greenhouse gases.

00:24:21.380 Uh, and I go through that in the book.

00:24:23.460 The fact that the, the lower troposphere, you know, the air near where we are is warming

00:24:28.660 quickly.

00:24:29.260 But in fact, if you go high enough in the atmosphere to the stratosphere, it's actually

00:24:33.480 cooling.

00:24:33.920 But it's only cooling there because the warming is caused by a heat trapping layer lower than

00:24:41.640 that.

00:24:42.440 So, you know, I don't, the point is I don't want to get technical, but one of the reasons

00:24:46.480 that scientists have so much confidence that humans are the cause is the theory predicted

00:24:52.180 that greenhouse gases would cause the warming.

00:24:55.360 The type of warming is the kind of warming that you would have expected from greenhouse gases.

00:25:02.280 And all of the other things that cause warming, A, aren't, you know, moving in the direction

00:25:08.440 of cause warming.

00:25:09.700 And again, the type of warming we're getting is not the type of warming they would cause.

00:25:13.840 That's why you get these incredibly strong statements that we know humans are the primary,

00:25:20.680 indeed, almost entirely the cause of recent warming.

00:25:23.240 Well, Joe, those are exactly the kinds of technical details I want you to bring forward,

00:25:27.720 because as you know, in the absence of a statement of the sort you just made, skeptics take the

00:25:35.480 fact that part of the atmosphere is warming and part is cooling as a sign of the ambiguity

00:25:41.920 of the situation, that even a coarser-grained source of confusion, true or feigned on the part of skeptics,

00:25:49.560 is the fact that what is predicted in terms of the results of global warming entails both conditions

00:25:56.920 of drought but also increased flooding.

00:26:00.160 And so now you have a, you know, a climate change skeptic laughing over the imponderable fact there that,

00:26:06.020 you know, what is this, some sort of scientific koan where you're telling me we're going to have a drought

00:26:10.100 and lots of flooding. So it's good for you to make sense of all of that as we move forward.

00:26:17.320 Before we get into the details of what's predicted, what are some of the feedback mechanisms

00:26:21.660 that cause this to get out of hand in ways that may be counterintuitive,

00:26:28.040 so that where an initial warming can become far more substantial?

00:26:32.840 Well, one of the best known feedbacks is the loss of ice on land and the ocean, particularly the Arctic

00:26:43.300 Ocean. So what happens is that as the planet warms up, of course, ice melts. Now, ice is highly

00:26:52.660 reflective. So if the ice is on the land, then as the ice retreats, you're exposing

00:26:58.620 the land, which is dark. And therefore, whereas, you know, ice might reflect 90, 95 percent

00:27:05.760 of the light that hits it, the ground absorbs most of the light. So you're actually, as the ice

00:27:12.660 retreats, you're, the earth is actually absorbing more of the sun's heat. And therefore, it heats up

00:27:20.260 faster. And therefore, the ice retreats more. And so that is, is, is one of the best known

00:27:26.580 feedback effects. And that is occurring both on land and, you know, as, as we get the reports year

00:27:33.860 by year, the Arctic Ocean, the Arctic ice cover, particularly during the summer, is retreating

00:27:40.120 rapidly. And again, when you replace ice covered ocean with the blue wavy ocean, you know, you get

00:27:47.740 the ocean absorbing considerably more of the sun's energy than it was when it had a nice insulation

00:27:54.640 blanket, if you will, from, from the ice. So that's a classic, that that's, that's called

00:28:03.300 a fast feedback. And that is, that is one of the best known. And we were clearly witnessing

00:28:08.620 it now. It's one reason, by the way, that the warming is occurring twice as fast in the

00:28:15.640 Arctic as it is in the rest of the globe.

00:28:19.500 And now there's also a feedback mechanism with respect to water vapor, right?

00:28:24.220 Yes, that's another fast feedback. So water vapor is a green, it's a heat trap in gas.

00:28:31.340 It is, it is. So when you start the initial process of warming through injecting a large

00:28:40.520 amount of greenhouse gases or changing the earth's orbit, then you start to evaporate more water.

00:28:49.500 As you warm up the planet and that water goes into the atmosphere and it also traps heat.

00:28:54.720 So that is a feedback too. Yes. And that's, that is a, another major fast feedback.

00:29:02.420 I think I've seen that fact in isolation seized upon by skeptics as a sign of just how preposterous

00:29:09.740 the situation is as described by science.

00:29:12.200 Yes. And, and, and, and again, this is the kind of thing if you, you know, skeptical science

00:29:16.080 will go into details. Oh, um, if, if anyone is interested that most of the warming is due

00:29:23.820 to the water vapor, but the excess water vapor is there because of the excess, uh, carbon

00:29:31.880 pollution. By the way, it should be said, people should understand that the greenhouse effect

00:29:36.800 is, is not controversial in the least. If you took that, we have an atmosphere. That's

00:29:41.920 why we have a habitable planet. That's why we're not Mars, right? If you took away the

00:29:46.840 entire atmosphere, the carbon dioxide, the water vapor, everything that traps heat, the

00:29:51.660 planet would be 60 degrees Fahrenheit colder. So there would not be a lot of places that would

00:29:57.280 be very hospitable, uh, uh, for life.

00:30:01.780 One problem here strikes me is that the changes in temperature that people are worried about

00:30:08.200 don't seem so great. When you look at your thermometer or you judge the weather for yourself

00:30:14.540 on any given day, when you hear about a two degree rise Celsius, you know, like 3.6 degrees

00:30:20.760 Fahrenheit or a four degree rise, or even in the worst case, and you know, an eight degree

00:30:26.660 rise. I mean, if you told me, you know, 30 years from now, my children will be living in 0.52

00:30:31.520 a world that is on average four degrees Celsius warmer. It's not immediately obvious why that

00:30:38.460 would be a big deal. You know, if you don't like the heat, you just move further north,

00:30:42.580 right? You just, you know, Canada is going to be great. What are the likely effects of these

00:30:48.620 changes in temperature as, as we go up in increments of two, four, and six degrees Celsius?

00:30:54.880 Well, I think this is a very good point. You know, first of all, obviously the rest of the

00:30:58.400 world talks Celsius and whereas Americans have, you know, in their mind that their temperature,

00:31:05.820 uh, gradations are, are based on Fahrenheit. So I, you know, I think it is better to talk about

00:31:11.820 Fahrenheit. It's still a small number, uh, you know, 3.6 degree Fahrenheit, um, is, is indeed

00:31:19.200 widely viewed in the side of the community and, and by essentially all the major governments in the

00:31:25.620 world, except our current one as a threshold beyond which climate impacts be moved from being dangerous

00:31:33.340 to being catastrophic at a very rapid rate. Um, now you can look at it a couple of different ways.

00:31:40.920 Uh, one of which is that the average temperature going up pushes the extremes up, uh, much faster.

00:31:50.380 And I have a chart in the book that shows that if you can visualize a bell curve in your head,

00:31:57.660 where at the very right side is that tail where you get the monster heat waves that really are

00:32:05.600 devastating to people in agriculture or the monster droughts or the monster super storms.

00:32:10.920 Um, there, they are a teeny fraction of the area under the bell curve. But if you now visualize that

00:32:18.840 bell curve shifting a couple of degrees to the right, all of a sudden, what had been very infrequent

00:32:25.460 events, all of a sudden, all of a sudden start to become quite frequent. Um, and that's why you hear

00:32:31.620 that like a super storm Sandy, which might be a once in a thousand year storm is now actually

00:32:39.720 under a once in a century storm. And in fact, Sandy was followed hurricane Irene, which was also

00:32:48.340 at the time of once in a century storm. And so you see, you know, you can't, you know, storms that used

00:32:54.520 to be once in a century, once in 500 years, if they're now coming every few years, you know,

00:32:59.540 it's because we've changed at the, at the high end of the far end of the bell curve, the frequency

00:33:04.900 of the really rare events. And historically it has been the really rare events that have done most of

00:33:11.820 the devastation in the history of hurricanes. It has literally been seven or eight or nine hurricanes

00:33:19.660 that have done half of the damage. You know, Katrina and Sandy, these are the two most destructive storms.

00:33:27.040 Um, and so they're outliers. So, uh, part one, the reason we worry about this is we're very concerned

00:33:33.760 about the outlier events because they're the true catastrophes. Secondly, um, you know, when you look at,

00:33:42.000 let's say, super storm Sandy, um, one of the things that warming changes is sea levels.

00:33:47.520 And as you raise sea levels, every storm that you see is going to have a storm surge, which is higher

00:33:55.060 and higher because it's the underlying, uh, uh, average sea level, uh, keeps going up. So, um,

00:34:03.440 you know, you get that impact of whatever the weather was going to be. Now you have global warming on top

00:34:10.560 of it. That's why, for instance, El Nino years, which, which are, you know, years that have freaky weather

00:34:16.800 and are slightly warmer than usual, they tend to be the hottest years on record because the,

00:34:21.720 the, the small amount of, uh, the extra regional warming from the El Nino is put on top of the

00:34:28.800 global warming trend. Now, you know, we've had, uh, 2014 was the hottest year on record and then 2015

00:34:34.840 beat that easily to become the hottest year on record. And then 2016 beat that. So we, you know,

00:34:40.580 we've been seeing unprecedented, you know, uh, uh, uh, records in warming and 2017 is on track to

00:34:49.680 probably be the second warmest year on record, but the hottest year on record without an El Nino.

00:34:56.220 So we're, we're starting to see the point is we're starting to see levels of warming that you

00:35:02.320 normally only see during extreme years be the normal weather. And, and so that's where, and

00:35:11.020 that's, in other words, the climate is changing. And that's what I try to tell people, for instance,

00:35:15.800 when I talk about drought, you know, you can look at the California drought, which lasted five,

00:35:21.320 six years, and that was the worst drought in a thousand years. But the point is that as you make

00:35:28.220 the average rainfall a little less and the average temperature higher, then suddenly that type of

00:35:35.880 drought becomes a 10 year drought or a 20 year drought. And instead of it happening every hundred

00:35:43.620 years, it happens every 10 years. So, um, that is one, you know, uh, obvious thing that, that is why

00:35:53.620 even small temperature changes can have a big impact. Just by the way, I mean, another analogy,

00:35:58.220 people use is, you know, uh, if you imagine a planet to be like a human being, it's designed,

00:36:05.640 you know, we, we spent 10,000 years at a relatively constant set of, of weather patterns over time.

00:36:13.440 The climate didn't change very much. Billions of people have chosen where to live based on their

00:36:19.580 knowledge of, is it too warm here? No. Is there enough rainfall to sustain life? Yes. Is the sea

00:36:27.800 level endangering us? No. So the point is we've literally 8 billion people are living in places

00:36:35.880 that they chose to live on, on, based on a relatively stable climate. You now add a few

00:36:41.380 degrees to that. And it's literally like adding a few degrees Celsius or, you know, or, or, or twice

00:36:47.720 that Fahrenheit five degrees, let's say Fahrenheit to your body temperature. So our entire body

00:36:55.060 temperature is constructed around 98.6. And we have mechanisms in our body, as I'm sure, you know,

00:37:01.000 to regulate that temperature. And if you start going outside of that bounds, it means something is wrong.

00:37:07.480 And if it stays outside that bound for a long period of time, it has dire consequences. Well,

00:37:12.620 the same is true for the climate. You know, if we could, if the planet warmed two degrees and

00:37:17.700 stopped, then we would adjust to that. But that still doesn't mean that the 8 billion people who

00:37:25.040 live where they do now wouldn't have to move, you know, a billion or 2 billion people moving,

00:37:30.780 you know, this is a catastrophe, right? I mean, we saw what two or 3 million refugees from Syria 1.00

00:37:38.140 turn global politics upside down. Well, let's talk, let's talk about that for a second. The,

00:37:44.960 the, why people would need to move, I guess, two obvious reasons come to mind. You're talking about

00:37:50.440 sea level change. So the inundation of certain coastal areas, and you're talking about the dust

00:37:58.420 bowlification of certain areas where we depend upon agriculture to be viable. Perhaps there are other

00:38:05.620 reasons that I haven't thought of. Tell me about certainly those two variables and anything else

00:38:11.800 relevant to, to ranging global politics. Sure. Well, people talk a lot about different

00:38:18.900 impacts. So it's certainly, I would, if your listeners come away from, from anything, I would

00:38:24.460 want them to, to, to think in terms of the, the two most worrisome impacts, um, is, is, uh, yes,

00:38:33.620 dust bowlification turning an area that was, let's say semi-arid, but could grow crops and sustain life

00:38:41.940 into something that's purely arid, ultimately a desert. But in the transition from it being semi-arid or,

00:38:49.460 or near semi-arid to becoming a desert, it's just going to get drier and hotter and, and, and droughts

00:38:56.020 are going to last longer and longer. And, um, we know that, uh, again, we, we have designed an

00:39:05.620 agricultural system of the world in which we, we feed large amounts of the world from relatively

00:39:12.780 small tracts of land. I mean, we have two bread baskets in this country, you know, the Midwest

00:39:18.020 extending to the Great Plains and, and California. Um, even though of course, Southern California is

00:39:23.760 essentially a semi-arid near desert climate. Um, so again, if you just shift the climate zones a

00:39:31.900 little bit, all of a sudden, uh, you, you find that your bread baskets are become, are, are getting

00:39:39.500 these mega droughts, uh, on a regular basis. And many of our crops are quite temperature sensitive.

00:39:46.000 People want to Google, you know, corn and temperature sensitivity. They will learn,

00:39:50.980 you know, a great deal about it. Um, so the point is that yes, um, you know, uh, uh, much of our,

00:40:00.940 our population is fed by an agriculture system that, that truly wants a stable climate, the, the,

00:40:07.800 the, the, you know, talk to a farmer, the thing they, you know, that, that causes the most problems

00:40:12.760 obviously is extreme weather variability, too much rain, too little rain. It's too hot or it's too cold.

00:40:20.120 Um, uh, so, uh, so that's an enormous problem. You know, literally, uh, uh, there are lots of

00:40:27.360 people living in places, uh, where they're not going to have sources of food. And, and by the way,

00:40:34.020 this is also related to sea level rise because many of our richest agricultural areas are deltas,

00:40:41.580 right? The, the, the Nile Delta, um, and the, the, the, the, the low lying areas of, of Bangladesh and

00:40:51.680 Southeast Asia. So you raise sea levels a couple of feet and suddenly the, the, the many, you know, 0.85

00:41:01.500 rich deltas that, that, that were, you know, feeding hundreds of millions of people, they are flooded.

00:41:07.340 And of course they're flooded with salt water and that salt water intrusion, by the way,

00:41:12.600 is already happening. As sea levels rise, salt water goes further and further up those deltas.

00:41:19.540 And, you know, if you Google salt water intrusion, you will find that is a mammoth problem already

00:41:26.180 for places like Egypt and Bangladesh and, and the water systems of Miami. Um, so part one is,

00:41:36.080 uh, are you going to be able to feed? I mean, we're going to have 10 billion people in mid-century.

00:41:41.720 And I, I wrote an article for nature on dust bowlification, just titled the next dust bowl

00:41:46.340 saying the biggest threat facing humanity is how are we going to feed 10 billion people

00:41:52.780 when we're moving in a rapidly changing climate to a world that has less potable water, less arable land

00:42:01.540 and, and, and much more intensive droughts and super storms. So, you know, that is problem number

00:42:11.060 one for billions of people and the choices that they've made where they live now. The second is

00:42:17.520 sea level rise. Uh, people, you know, most of the population of the world or half the population

00:42:22.900 of the world lives within, you know, 50 miles of the ocean. Uh, people like to be near water. Water

00:42:30.040 makes, has made trade possible. Your, most of your major cities, uh, are near waterways near the ocean

00:42:37.080 historically, uh, and even today. So, um, we have, you know, uh, billions of people, uh, you know,

00:42:45.140 and so we have hundreds of millions of people who live right on the ocean, you know, and in places

00:42:50.680 like Bangladesh and even places like, you know, Miami and Louisiana and Norfolk, Virginia, or even

00:42:56.980 Los Angeles. Um, we have staggering amounts of people who live where they live because sea levels

00:43:05.460 have been, uh, you know, until recent decades, pretty damn stable. And we're now moving to a

00:43:12.060 situation where we, we are, uh, uh, where the worst case scenarios of sea level rise appear to be the

00:43:20.080 ones that we are facing. And if you were to have a leading expert, a glaciologist expert on Greenland

00:43:26.740 or Antarctica, um, they would tell you that the, the, the great ice sheets are melting much faster

00:43:33.820 than anyone thought. And that we may be much closer to tipping points beyond which we can't stop,

00:43:40.040 uh, them. And therefore we, uh, we look to be headed to what used to be, uh, the worst case

00:43:49.020 levels of sea level rise are now pretty much the business as usual projections and talking about

00:43:54.980 three, four and five feet. Um, and you know, if you, you can go online and find, you know, uh,

00:44:02.460 programs that allow you to look at the coast of the world coast of different cities under three,

00:44:07.660 four or five feet. But I can tell you that all of South Florida, if you've been there, you know,

00:44:14.640 how flat and low lying it is. It's simply not possible that South Florida is, is habitable,

00:44:22.240 uh, uh, at, you know, uh, by the end of the century under those scenarios, but the same is true 0.81

00:44:28.160 of Bangladesh and the same is true of, you know, uh, uh, lots of places in this country and lots of

00:44:34.160 places around the world. So again, we are talking about places where hundreds of millions of people

00:44:40.160 live are simply going to be either underwater or they're just going to be routinely drenched

00:44:46.580 in storm surges. I mean, after all, you don't, you know, you, you, you know, we don't live in

00:44:51.800 places that are, you know, routinely dunked by storm surges, but all the storm surges are on top of

00:44:57.480 the sea level rise. So we don't, you know, no one lives, I didn't say no one, but we don't live

00:45:02.160 right at sea level rise, right? Cause you have the tides and you have storm surges. So yes, the kind

00:45:09.160 of withdrawal is starting to happen, you know, is going to be sped up. And so we are going to end up

00:45:15.140 with a hundred serious worth of failed states, inundated areas and, and refugees. That's, 1.00

00:45:25.420 that's where we're headed towards. And that's of course why the Pentagon is incredibly concerned

00:45:31.980 about climate change. And, and the Pentagon has been issuing report after report saying,

00:45:37.120 you guys, climate change is going to become a major driver of civil conflict. Um, as people fight

00:45:45.780 for scarce fresh water, as people are forced down their homes. If you'd like to continue listening

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Making Sense - Sam Harris - September 05, 2017

#95 — What You Need to Know About Climate Change

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