Making Sense - Sam Harris - #333 — Sanity Check on Climate Change

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

00:00:23.020 This is Sam Harris.

00:00:25.740 Today I'm speaking with Chris Field.

00:00:28.020 Chris is the director of the Stanford Woods Institute for the Environment and the Melvin

00:00:34.080 and Joan Lane Professor for Interdisciplinary Environmental Studies at Stanford University.

00:00:39.360 Prior to his appointment at the Stanford Woods Institute, Chris was a staff member at the

00:00:44.520 Carnegie Institution for Science and founding director of Carnegie's Department of Global

00:00:50.000 Ecology.

00:00:51.520 Chris's research has focused on climate change.

00:00:53.860 He is a very influential scientist in the field, widely cited.

00:01:00.000 He's especially focused on solutions that improve our lives now and decrease the amount

00:01:05.220 of future warming.

00:01:06.800 He's been deeply involved in the national and international efforts to advance our understanding

00:01:10.760 of global ecology and climate change.

00:01:13.860 Chris has also overseen many of the efforts of the Intergovernmental Panel on Climate Change,

00:01:18.040 as you'll hear.

00:01:20.100 He's also been elected to the U.S. National Academy of Sciences, the American Academy of

00:01:24.980 Arts and Sciences.

00:01:26.280 He's received the Max Planck Research Award, among others.

00:01:30.460 And he holds a bachelor's degree in biology from Harvard and a Ph.D. in biology from Stanford.

00:01:36.460 Anyway, I wanted to get Chris on the podcast because I wanted a sanity check, frankly, about

00:01:42.980 climate change.

00:01:43.700 It had been a couple of years since I'd done a podcast on the topic.

00:01:47.180 We are now in a political season where Republican candidates for the presidency can be heard

00:01:52.640 saying things like the climate change agenda is a hoax.

00:01:56.200 So I just wanted to get a top-flight research scientist here to articulate what the mainstream

00:02:03.540 scientific consensus is on climate change, our contributions to it, the promise of mitigating

00:02:10.860 it, what the future is likely to look like, etc.

00:02:14.960 Obviously, this is another PSA, so no paywall.

00:02:18.840 But if you want to support the podcast, the way to do that is to subscribe at samharris.org,

00:02:25.200 which makes all of this possible.

00:02:27.980 And now I bring you Chris Field.

00:02:35.400 I am with Chris Field.

00:02:37.240 Chris, thanks for joining me.

00:02:39.240 It's my pleasure.

00:02:39.840 Thank you.

00:02:40.800 So we're going to talk about climate change, what we know about it, what we don't know

00:02:45.680 about it, what many of us refuse to know about it.

00:02:49.120 But first, describe your background.

00:02:51.820 What work have you done on this issue?

00:02:54.880 My degrees are in biology.

00:02:56.940 But when I started my academic career, I turned really right at the outset to trying to understand

00:03:04.120 big picture issues of how global change was altering ecosystems, altering biological diversity, altering

00:03:12.980 plant growth, and just changing the natural world.

00:03:17.360 Most of my early work in this space was experimental and spent several decades doing experiments, especially at Stanford's

00:03:26.600 Jasper Ridge Biological Preserve, where we altered the environmental conditions for entire

00:03:31.980 chunks of grassland ecosystems.

00:03:34.120 We changed the concentration of carbon dioxide in the atmosphere.

00:03:37.760 We changed the amount of rainfall.

00:03:39.640 We changed the temperature that the ecosystems were going into and had a front row seat for

00:03:46.160 looking at what happened to ecosystems when they were exposed to the kind of climate conditions

00:03:52.160 that we expect in the future.

00:03:53.960 In parallel with that work, my group started doing assessments of what we know about what's

00:04:01.060 happening with the global carbon cycle, and in particular, why ecosystems on land have been

00:04:08.040 so successful at taking up a large fraction of the carbon dioxide that's emitted from fossil

00:04:15.200 fuel combustion.

00:04:16.660 That work led to a whole bunch of different characterizations of plant growth across the

00:04:23.720 entire biosphere, covering not only the land, but also the oceans.

00:04:27.860 Around the time we started doing these global scale synthesis, I also got involved in the

00:04:33.860 Intergovernmental Panel on Climate Change and found that just a wonderful opportunity to broaden

00:04:39.720 my understanding and my perspective.

00:04:42.520 So for the IPCC fourth assessment report, I was what they call the coordinating lead author,

00:04:48.280 the person in the crosshairs for the chapter on North America, where we tried to assemble

00:04:53.700 basically everything that's known about climate change impacts expected on North America,

00:04:58.840 what we can do to adapt, who's vulnerable and who's not.

00:05:03.960 And then for the IPCC fifth assessment report, which was published in the 2013-14 timeframe,

00:05:09.840 I served as the co-chair, again, the person in the crosshairs for the whole report on impacts,

00:05:19.260 adaptation and vulnerability, and really, again, had the bird's eye view of everything that

00:05:24.040 we know about climate change impacts around the world.

00:05:26.920 Since the IPCC era, which really for me ended in around 2014, I've been focusing on climate

00:05:36.480 change solutions, natural climate solutions, how we can take better care of our soils and

00:05:42.560 forests and oceans, and on technology-based solutions, how we can more rapidly transition

00:05:48.900 to an energy system that doesn't emit greenhouse gases.

00:05:52.500 And what's your current position at Stanford?

00:05:56.180 Well, my main job is that I'm director of the Stanford Woods Institute for the Environment.

00:06:02.600 And for nearly two decades now, the Woods Institute has been incentivizing members of the Stanford

00:06:10.900 community, faculty, students, neighbors, to be involved in interdisciplinary solutions-oriented

00:06:19.140 research about critical environmental issues, issues involving climate, food, water, health,

00:06:26.260 the oceans.

00:06:27.780 And it's been a wonderful opportunity to build bridges between researchers, to help people

00:06:35.880 observe and discover new aspects of their work, and to really push the frontiers.

00:06:42.820 And what I think of as laying the foundations for Stanford's bold new investment in the Stanford

00:06:50.500 Doerr School of Sustainability.

00:06:53.620 John Doerr gave a very big grant to Stanford, didn't he?

00:06:56.320 A large gift, a transformational gift, and it's one that I am confident is really propelling

00:07:04.200 Stanford not only to the front ranks of university, but to the front ranks of leading progress in

00:07:09.420 tackling the climate crisis.

00:07:10.600 Well, I want to talk about the science and the mitigation solutions, and really, I just

00:07:18.180 want to track through all that we know about this.

00:07:20.960 But I want to start with some of the skepticism that all of us perceive, certainly right of 1.00

00:07:27.700 center on the political landscape.

00:07:29.460 And, you know, so if you're just a consumer of media at the moment, you know, the moment

00:07:35.540 you tack right of center, you meet a fairly pervasive concern that our climate problem has

00:07:45.980 been overblown, right?

00:07:47.240 There's this sense that there's this new catastrophism, there's an anti-capitalist agenda, there's a new

00:07:54.220 religion of fear and guilt, complete with its priests, and, you know, we have, for all 0.67

00:08:00.060 intents and purposes, what appears to be a, you know, an emotionally vulnerable teenager

00:08:05.260 serving as a Joan of Arc character for this movement.

00:08:09.780 And I'm referring, of course, to Greta Thunberg.

00:08:12.000 And it's just, you know, and the optics of all of this, I mean, whatever good that has

00:08:17.000 accomplished, real or imagined, on the left, on the right, the optics are quite a bit different.

00:08:23.260 And as far as I can tell, many skeptics seem to believe at this point that they're on very

00:08:28.420 firm ground in saying that our models for climate change, going back decades, have been

00:08:34.120 basically wrong.

00:08:35.840 So I want to start there.

00:08:37.460 How have our models looked, and to what degree have they been borne out over the last 30 or

00:08:44.420 40 years since we've been articulating them?

00:08:47.440 What, if anything, have we been wrong about up until this point, and just how solid has

00:08:54.200 the story become in recent years?

00:08:57.980 Let me start out with a brief comment about the history of skepticism about climate change.

00:09:04.640 And as Naomi Oreskes has documented in her really brilliantly researched book, the history

00:09:13.040 of skepticism has deep roots in interests that have been opposed to transitioning away from

00:09:20.320 fossil fuels.

00:09:21.100 But it really got going in an era when we really couldn't concretely document that the climate

00:09:30.800 was already changing as a consequence of human actions.

00:09:35.440 Back in the 1980s and the 1990s, we had a solid theoretical understanding of where we were

00:09:46.160 headed.

00:09:46.500 We could certainly see the concentration of greenhouse gases in the atmosphere increasing, and it

00:09:52.660 was getting warmer.

00:09:53.880 But it wasn't getting warmer in a way that was right in your face for people around the world.

00:09:59.320 But we also weren't seeing dramatic changes in the frequency or severity of extreme events.

00:10:07.660 And since about 2010, that's really dramatically changed.

00:10:12.560 And almost everyone has a personal experience with the fact that the climate is different now

00:10:21.300 than it was only a few years ago.

00:10:23.420 Many more heat waves, many more examples of heavy precipitation, the exact kinds of things

00:10:31.780 that the climate science community has been predicting for decades are really playing out

00:10:37.460 in real time.

00:10:39.460 And if you look at the predictions from, for example, the IPCC, what you see is that the central

00:10:49.280 forecasts of where we would be with temperatures in the 2020s that the IPCC made in 1990 were bang on.

00:11:02.260 There really hasn't been any systematic problem with any of the calculations.

00:11:10.500 And it's important to understand why this is.

00:11:12.560 It's the fact that carbon dioxide, greenhouse gas, has been understood since the middle

00:11:19.380 of the 19th century.

00:11:21.760 In 1896, the million Swedish chemists, Van Theirinius, published a paper where he knew

00:11:28.380 in 1896 that the three things you need to do to make an accurate forecast of how much increasing

00:11:35.480 CO2 changes climate.

00:11:37.180 He knew that carbon dioxide is a greenhouse gas.

00:11:39.540 He knew that a warmer atmosphere will hold more water vapor and that that increase in water vapor

00:11:46.260 will amplify the warming effect of the carbon dioxide.

00:11:50.340 And he knew that over the course of several decades, CO2 that's added to the atmosphere

00:11:55.980 gradually partitions between the atmosphere and the oceans so that eventually about 80% of it

00:12:01.420 ends up in the oceans.

00:12:02.860 With those three things, he was able to make a back-of-the-envelope calculation of how much warming

00:12:09.160 we'd expect with a doubling of carbon dioxide.

00:12:12.660 He didn't get exactly the right answer, but it was pretty darn close.

00:12:16.120 And that was, what, 127 years ago.

00:12:21.780 And in that 127 years, the science has only gotten more and more solid on those foundational

00:12:28.560 elements and on the interactions that mean that the actual outcomes might be somewhat worse

00:12:36.200 or somewhat less bad in particular locations.

00:12:39.580 So, I mean, one problem here, it seems to me, is that the magnitude of the change just doesn't

00:12:45.860 sound that bad to most people.

00:12:48.480 I mean, anyone who's steeped in the science, as we're going to show here, learns how to interpret

00:12:55.760 these numbers.

00:12:56.420 But, you know, if you just told me in my naive state that 30 years from now, my children

00:13:02.620 would be living in a world that is, on average, 3 degrees Celsius, warmer than it is now, it's

00:13:07.640 not immediately obvious why that would be such a bad thing.

00:13:11.500 I mean, if you don't like the heat, you can move a little north.

00:13:14.720 Yes, some people are going to lose their beach houses when the sea levels rise.

00:13:20.500 Life in Bangladesh isn't going to be so great, but life in Bangladesh has never been so great. 1.00

00:13:24.300 So it's easy for people to just log this whole concern as nothing more than a hypothesis, and

00:13:33.700 the knock-on effects of these global mean temperature changes are, at best, speculative and sort of

00:13:42.800 hard to worry about.

00:13:44.480 How would you address that intuition?

00:13:47.580 Well, there are a bunch of elements to the narrative that you just spun out.

00:13:52.440 The first is that a small amount of warming, particularly when described in Celsius degrees,

00:13:58.620 doesn't sound like much.

00:14:00.380 And I think it's useful to talk in Fahrenheit degrees, where each Fahrenheit degree is, of

00:14:06.880 course, 1.8 Celsius degrees, and makes it clear that these are real numbers.

00:14:13.240 They're easy to measure.

00:14:14.720 And I think what is probably the most important fact for people to understand is that an average

00:14:25.180 warming of 2 or 3 or 4 degrees Fahrenheit is not going to be existential for most people

00:14:33.560 in most places around the world.

00:14:35.500 But the increase in the frequency and the intensity of extreme events has the potential to be the

00:14:42.740 kind of extreme heat that we saw in Phoenix this summer, for example, or the kind of heavy

00:14:50.140 precipitation that we saw with the devastating floods in Pakistan last year.

00:14:55.040 Those are good examples of the kinds of events that we have high confidence are connected with

00:15:02.640 warming.

00:15:03.500 And we know that not only with a warmer climate do we automatically see more extremes just because

00:15:13.980 we've shifted the center of the distribution of climate outcomes, but we also know that a warmer

00:15:21.100 climate has mechanisms that are making it more variable.

00:15:26.120 So those two things really push us into a situation where we're really spending a huge amount of time

00:15:34.740 and effort and Monday preparing for extreme events and coping with the consequences of extreme events.

00:15:41.840 But I do want to address another aspect of your question about the sense of overplaying the

00:15:49.700 catastrophic consequences.

00:15:51.540 And I don't think you see that from the scientific community, but there are lots of descriptions in the

00:15:59.480 public narrative that over-dramatize the kinds of impacts that we can expect, particularly if we do a

00:16:08.660 good job of tackling climate change and limiting warming to something like the goals of the Paris

00:16:15.360 agreement, well under two degrees Celsius or about three and a half degrees Fahrenheit.

00:16:22.000 And if we can be successful at limiting the warming to that range, we'll see impacts that are existential for

00:16:32.820 some regions, low-lying islands, coastal areas around the world.

00:16:37.540 Many people will die unnecessarily as a result of the exposure to high temperatures or being caught in a wildfire that's

00:16:48.520 climate-stimulated.

00:16:50.200 But those aren't conditions that are likely to be existential for humanity or for society or for the

00:16:58.500 global economy.

00:17:00.060 There are conditions that we should be avoiding because we have the potential to do that.

00:17:04.520 It's smart, it's affordable, and it will provide a better quality of life for citizens around the world.

00:17:13.520 But that's different than saying, unless we drop everything and focus solely on climate tomorrow,

00:17:22.480 civilization will disappear at any given date.

00:17:25.880 This is a complicated, important, critical-to-address problem because it has lots of leverage on the future,

00:17:36.000 not because we're on the edge of a precipice that's likely to be civilization ending.

00:17:43.580 So I want to ask one more question in a skeptical vein here, because you just mentioned wildfires, and we're having

00:17:52.360 this conversation with wildfires raging in various places.

00:17:57.040 And much of this in the media gets attributed to climate change.

00:18:01.220 It's just a very straightforward claim that this is evidence of climate change.

00:18:05.920 This is a consequence of our irresponsibility on this issue.

00:18:09.940 And so we have fires in Canada and Greece and recently Maui raging to great effect with attendant loss of life

00:18:20.080 and massive amounts of pollution.

00:18:22.460 But then I read in the Wall Street Journal that this is really just false reporting,

00:18:30.200 that this is much more of a story of failures of forest management and fire control and even arson.

00:18:37.240 And in fact, the percentage of the earth that burns each year has declined steadily since 2001, right?

00:18:46.620 So the last two decades has not been a story of increased wildfire consequence globally.

00:18:54.400 In fact, there's been a reduction there.

00:18:56.400 So again, this is just the kind of the muddled message of what is real.

00:19:01.420 Well, wildfires, critically important issue, horrendous impacts on the affected communities.

00:19:10.560 It just has to go out to the people of Maui, Paradise, Santa Rosa, all the communities that have been affected.

00:19:19.300 And the wildfire story has a whole bunch of different pages.

00:19:22.400 It is certainly true that the global area burned in wildfires has gone down consistently over the last couple of decades.

00:19:34.000 That is entirely a story of African savannas.

00:19:38.360 Three quarters of the global area that burns every year burns in African savannas.

00:19:43.540 Those are mainly related to agricultural practices and rangeland management.

00:19:48.500 And those practices have been changing.

00:19:51.880 At the same time, if you look at regions like the western United States,

00:19:56.220 there's been a dramatic increase in the area lost in wildfires.

00:20:01.020 And we've seen that in many regions of the world, including the Mediterranean and in Australia.

00:20:08.060 Okay, sorry.

00:20:08.920 So there's been an increase in the Mediterranean and western North America,

00:20:12.740 but there's been a massive decrease in Africa.

00:20:16.060 Okay.

00:20:16.260 And the African fires are almost entirely savanna fires, grassland fires.

00:20:22.640 And of course, the consequences for recovery for the global carbon cycle are much different for these grassland and savanna fires

00:20:33.100 than they are for forest and chaparral fires like we have in North America.

00:20:37.660 But it also is true that there are a number of factors that have contributed to the increase in fire risk in many of these fire-prone ecosystems.

00:20:51.680 In western North America, we know that decades of fire suppression allowed the accumulation of large amounts of highly flammable material.

00:21:03.460 And we know that in western North America, there's been a huge influx of people into what we often call the wildland-urban interface,

00:21:14.300 but into forested regions that are susceptible to wildfire.

00:21:17.900 And those two factors, when coupled with the increased tendency for these forests to generate unmanageable conflagrations as a result of climate change,

00:21:32.080 has really changed the picture.

00:21:33.520 And in western North America, especially in California, we really have seen a transition from fires that were manageable in a kind of professional fire sense,

00:21:48.300 even though occasionally they had devastating consequences, to fire behavior that's really unprecedented.

00:21:54.120 And it has resulted in a huge increase in the area burn and a frustrating and devastating increase in loss of lives and wildfires.

00:22:05.220 And with any particular fire, it's hard to know what the contribution of climate change was until it's been thoroughly evaluated.

00:22:13.900 I think with the fires in Maui, we still don't have a clear picture.

00:22:18.020 Okay, so let's track through this somewhat systematically here.

00:22:22.280 And what I'd like you to do is demarcate what is totally uncontroversial from a scientific point of view from the gray areas.

00:22:31.200 Because insofar as there's a through line here that is analogous to the claim that smoking is bad for your health,

00:22:39.660 you know, something that's totally non-debatable at this point in medicine,

00:22:42.980 and I want us to keep that in view.

00:22:45.900 And then when we wander off of that level of certainty, I'd like us to flag it.

00:22:51.620 So just to begin with, how are global temperatures measured?

00:22:57.820 How are we getting this data?

00:23:00.240 And what, if any, are the main sources of uncertainty with respect to the measurements and the models we're developing as a result of them?

00:23:10.300 We have a really accurate record of global temperatures going back to the latter decades of the 19th century.

00:23:19.760 Around 1880, we had a sufficient number of carefully instrumented and observed weather stations and ocean observations

00:23:31.580 to be able to develop a high confidence record of global temperatures.

00:23:37.720 And that core record, which is now maintained in a bunch of different research institutions,

00:23:44.340 is based on tens of thousands of thermometers.

00:23:51.220 There are millions of ocean observations and just an incredibly carefully curated record.

00:24:00.640 And there's been a huge amount of scholarship in figuring out what happens when the area urbanizes around a weather station

00:24:12.480 and there are gaps in the record.

00:24:15.800 And all of that has been really super carefully filtered out so that the different groups that are doing the analysis,

00:24:24.200 including one really prominent group that's based at UC Berkeley and started out to prove that the instrumented temperature record wasn't all that great,

00:24:35.660 ended up demonstrating that it was spectacularly good.

00:24:39.720 And they got exactly the same thing as NASA and the UK Met Office and the other groups that are doing the temperature records.

00:24:46.820 So we have basically thermometers that have been deployed around the world that have been measuring temperatures of air and ocean water for about 140 years.

00:24:59.520 And those are increasingly augmented with satellite data.

00:25:04.560 For a while, there was a thread running through the skeptical climate science literature that the satellite data wasn't showing the same amount of warming that we were getting with the surface observations

00:25:21.500 and that there must be something wrong with the surface observations.

00:25:25.420 But it turns out that once the orbital dynamics of the satellites were understood and appropriately corrected,

00:25:35.300 that the temperature record from the satellites is essentially identical to the temperature records from the thermometers.

00:25:43.100 So we now have not only these instrument records and the satellite records,

00:25:48.400 but we have literally tens of thousands of different kinds of ecosystem markers that are telling us the same thing.

00:25:57.180 We have things like flowering dates of different plants.

00:26:01.040 We have the hatching, nesting dates of birds.

00:26:06.080 And these observations around the world really paint exactly the same picture,

00:26:11.500 a picture where we have seen to date a warming of a little more than one Celsius,

00:26:19.840 about two degrees Fahrenheit over the last century,

00:26:23.600 and a warming that has rapidly accelerated since around 1990.

00:26:31.280 How do we differentiate the natural climate variability from human-induced change?

00:26:38.460 Obviously, the climate has changed over its history, and we have some record of that.

00:26:44.080 And I guess I could also add the question here,

00:26:48.720 how do current CO2 levels compare to historical levels?

00:26:55.460 Do we actually think we know the percentage of change that is human-induced at this point?

00:27:00.240 In the CO2 concentration and in the temperature, we have a good record of both.

00:27:05.360 So this question of what historical variability will look like, of course, is quite different.

00:27:12.780 If you look on different timescales, we have good records of temperature that we can extend back

00:27:22.340 the order of a thousand years based on something that feels like instruments,

00:27:28.460 and we can have high confidence that the instrumented temperature is now the highest it's been in the last

00:27:36.380 thousand years or so based on that.

00:27:38.420 We also have really excellent temperature proxies from ice cores that have been extracted from the Greenland ice sheet

00:27:47.700 or from alpine glaciers around the world or from the Antarctic ice sheet.

00:27:52.320 And depending on the resolution that one wants, we can get annual resolution back thousands of years

00:28:01.020 from the Greenland ice sheet or almost a million years from the Antarctic ice sheet.

00:28:07.800 And across all those records, what we can see is that there have been periods when the climate was very different than it is now.

00:28:17.680 There was a period around 7,000 years ago that was comparably warm to what we're seeing now.

00:28:23.320 And there have been many periods when the climate was substantially colder, ice ages, over the last several million years.

00:28:32.380 And we understand a lot about what's causing those.

00:28:34.760 In fact, some of the best evidence that carbon dioxide drives changes in climate comes from reconstruction of what happened

00:28:44.880 during the ice ages that the Earth has gone through for the last several million years

00:28:50.440 and for which we have these really good ice core temperature records for about the last 800,000.

00:28:55.500 And you said we've experienced slightly over a degree Celsius increase in mean global temperature over the last century,

00:29:05.460 so just shy of 2 degrees Fahrenheit. Is that right?

00:29:09.480 Yes, right around 2 degrees Fahrenheit.

00:29:12.560 And as far as the models, predictions from here, what is predicted?

00:29:18.020 And are there competing models?

00:29:19.320 How much variance is there between models, or is there a real convergence with respect to the scientific picture here

00:29:27.920 as far as the possible range of temperature increase we can expect, I guess,

00:29:35.820 bounded by the most aggressive conceivable mitigation strategy versus our just living in a business as usual,

00:29:45.020 racing toward the brink style of increased industrialization and zero mitigation?

00:29:52.260 What's expected?

00:29:53.580 Well, what we know now is that the biggest source of uncertainty in the decades ahead is what we do.

00:30:03.380 And there's a huge difference between a world of ambitious mitigation where greenhouse gas emissions are tackled aggressively,

00:30:12.280 brought down to zero, and the greenhouse gases already in the atmosphere are removed,

00:30:17.320 and the kind of opposite a world of continued high emissions where countries, companies, individuals decide that they're not going to tackle the problem

00:30:29.160 and continue to invest heavily in infrastructure and utilization of fossil energy of emissions-intensive agricultural techniques and clearing of forests.

00:30:43.460 And with the most ambitious conceivable actions, we can limit warming to somewhere in the range of one and a half to two C,

00:30:58.700 the Paris Agreement says we're committed to limiting warming to well under two degrees Celsius.

00:31:04.820 And in the world of continued high emissions, we might see a global average temperature in 2100 between four and five degrees Celsius warmer than pre-industrial.

00:31:21.220 Now, one really dramatic, amazing, and encouraging sign is that 10 years ago,

00:31:29.620 it looked like we were on a trajectory to be in this world of continued high emissions.

00:31:37.900 In the IPCC literature, it's called RCP 8.5, representative concentration pathway with eight and a half degree of watts per square meter of additional climate heating.

00:31:51.380 And that was designed as a picture of a world where there were no constraints on using fossil fuels,

00:32:02.360 no particular progress in limiting them, and no real effort to turn away from a high emissions lifestyle.

00:32:11.660 When we look now at where we're headed in a kind of a most likely outcome,

00:32:18.300 the estimates range from this Paris compliant to one and a half to two C to more like three C globally.

00:32:30.060 That's a dramatic progress.

00:32:32.520 And in some sense, you can say, wow, we've already solved maybe 25% or maybe even a third of the total climate problem

00:32:44.920 as a result of technological progress and policies that have been implemented in the last decade or so.

00:32:54.200 And it is really remarkable progress.

00:32:56.680 And it's in documentation that meaningful change can come from modest deployment of things that we already know how to do and are affordable.

00:33:08.080 I think that that's in many ways the undersung triumph of the transition to a sustainable world is that we have moved dramatically away from this RCP 8.5 world of continuing high emissions.

00:33:25.600 Well, I want to talk about the details of what it would take to transition further into a low carbon economy.

00:33:34.340 But before we do that, let's talk about some of the feedback mechanisms here,

00:33:39.420 because some of them are pretty surprising and even perverse.

00:33:45.120 For instance, water vapor is a greenhouse gas,

00:33:49.060 and yet certain forms of air pollution have a net cooling effect, right?

00:33:55.240 So do we want less water vapor and more sulfur dioxide and soot in the atmosphere?

00:34:00.820 I mean, it's just a, actually, there was a piece published in the New York Times today,

00:34:05.380 citing, I believe, a paper in Nature from, I think, last year,

00:34:09.400 that claimed that without all of our industrial air pollution over the last century,

00:34:14.260 the temperature increase would have been 30 to 50 percent higher, right?

00:34:19.240 Because all of these polluting aerosols exert this cooling effect by reflecting sunlight back into space.

00:34:26.300 And yet, we know that air pollution, it's estimated, kills around 10 million people a year, right?

00:34:31.960 So air pollution is a major concern in its own right.

00:34:34.980 And it's also true that the air pollution and the greenhouse gases are produced by the same behavior.

00:34:39.920 But it's just, there's this perverse fact that if we just got busy cleaning up the pollution side of it,

00:34:47.600 we could expect more warming.

00:34:50.400 And it just seems like a terrible outcome.

00:34:52.520 And it even has, I think, like locally concentrated implications.

00:34:56.780 So where, you know, if you really clean things up in India, say, you know, 1.00

00:35:00.560 India would experience extreme heat events even worse than they otherwise would.

00:35:07.120 Can you talk in general, I mean, feel free to address that, that specific case,

00:35:12.000 but can you talk in general about what we know about feedback loops in the climate system

00:35:18.460 and how they complicate the picture here?

00:35:23.480 It's important to recognize that there are many climatically active substances.

00:35:31.160 Water vapor is a powerful greenhouse gas.

00:35:33.240 And the effect of extra water vapor that stays in the atmosphere as a consequence of warming

00:35:43.060 from carbon dioxide is really substantial.

00:35:46.060 It amplifies the warming from CO2 by more than half.

00:35:52.220 But it's not like we can regulate that.

00:35:55.400 The amount of water in the atmosphere is controlled by the temperature of the air.

00:36:00.460 Warmer atmosphere holds more water vapor.

00:36:03.480 And they're vast areas, 70% of the Earth is ocean.

00:36:06.820 And the water is freely evaporating into the atmosphere.

00:36:11.280 And so you can think about it as a kind of vicious cycle feedback that the more CO2

00:36:17.840 is in the atmosphere, the warmer it is, the more water vapor the atmosphere will hold.

00:36:22.600 And then it makes it warmer still.

00:36:23.940 So water vapor is simply a part of the system that amplifies the effect of carbon dioxide.

00:36:33.520 There's one important wrinkle on that, and it's that water vapor doesn't get very much

00:36:42.240 into the upper layers of the atmosphere, the stratosphere.

00:36:45.420 And one of the reasons that the emissions from jet airplane travel are so important for climate

00:36:55.060 is that jets deliver a substantial amount of water to the stratosphere where it has this

00:37:01.780 warming effect and stays in the atmosphere longer than it would if it was at lower elevations.

00:37:08.260 So water vapor, super interesting, important.

00:37:10.740 And except for the wrinkle about jet airplane travel is not a lever about climate that we

00:37:18.960 can control, but we are always going to see this amplifying effect of water vapor.

00:37:25.220 Air pollution aerosols have the effect in general of reflecting sunlight back into space,

00:37:34.880 resulting in conditions that are cooler than they would otherwise be.

00:37:41.540 But air pollution aerosols are devastating for human health around the world.

00:37:47.180 Millions of people every year die as a result of exposure to air pollution.

00:37:52.640 And a critical priority for environmental action is to find a way to decrease this pollution,

00:37:59.020 recognizing that if we were dramatically successful at decreasing levels of aerosols, we would end

00:38:10.260 up with climate conditions that were substantially warmer in some places.

00:38:17.520 And it is also the case that the aerosol effects tend to be quite local because the lifetime of

00:38:27.940 most of the pollutant aerosols is for a short few hours to a few days, as opposed to centuries for carbon

00:38:35.800 dioxide. With carbon dioxide, the climate effects are felt everywhere. Aerosols tend to be much more

00:38:42.360 local. So that means that, as is the case for water vapor, that aerosols don't make the job easier,

00:38:52.020 but they, but they, but they still point a path to a solution and we need to clean up the air pollution

00:38:59.040 that's responsible for all these deaths. And, and the biggest problem areas are emissions from coal-fired

00:39:07.180 power plants and emissions from diesel engines. We know how to address both of those with renewable energy

00:39:13.900 to make more progress. And we need to recognize that as we do that, we'll save millions of lives,

00:39:21.020 but we'll have to work harder and faster on decreasing emissions of greenhouse gases because the aerosols have

00:39:29.280 been hiding some of the greenhouse gas effect. Let me mention one other aspect of aerosols that

00:39:38.220 people are increasingly beginning to discuss. We know from observations of air pollution aerosols from

00:39:47.080 power plants and stuff, and, and especially from historic volcanic eruptions that injections of large

00:39:55.620 amounts of aerosols into the stratosphere and elevations of 12 to 20 miles above the surface

00:40:03.420 can produce a significant cooling of climate. The Philippine volcano Pinatubo that erupted in

00:40:12.020 1991 resulted in a global cooling of nearly one degree Fahrenheit for about two years as a result of putting

00:40:24.000 large amounts of sulfur dioxide into the stratosphere, producing aerosols that reflected sunlight and cooled

00:40:32.400 the planet. And there have been many calls for exploration of whether we might want to use

00:40:41.500 this. It's often called solar geoengineering or solar radiation management to prevent some of the

00:40:49.980 warming from occurring. Even at the same time, we're recognizing that that's not a comprehensive

00:40:55.860 solution to climate change. The idea of injecting essentially air pollution into the stratosphere is

00:41:04.480 that that's a part of the atmosphere, which is not primarily influencing people's health. And where because of the

00:41:14.120 way the atmosphere works, material in the stratosphere stays there for one to two years, and the quantity that you

00:41:22.320 would need in order to have a significant effect on climate would be much less than the quantity

00:41:27.200 that would have the same effect closer to the surface.

00:41:31.220 Is there much energy behind that as a mitigation approach at this point? Or is that just a

00:41:37.540 kind of a Faustian bargain that we don't really want to think about?

00:41:41.600 Well, the U.S. Office of Science and Technology Policy recently released a report recommending that

00:41:50.960 the U.S. government invest in understanding whether or not this kind of solar geoengineering

00:41:58.180 is worth considering. I'd say we're at the very early stages. But at the stage where there have been

00:42:04.880 in the order of 2,000 scientific papers published on how it would work, what the risks might be,

00:42:12.660 what the social and political dynamics might be associated with it. So there are tons of things we

00:42:19.400 don't understand, but it's increasingly coming into focus as what you might think of as an emergency

00:42:28.140 action for dealing with overshoot. So what do you perceive to be the most important challenges

00:42:36.320 in our transitioning to a truly sustainable, low-carbon economy? What are the major impediments

00:42:46.100 at this point? I think the biggest challenge we face is the challenge of building a durable

00:42:53.840 political coalition around action on climate. The Inflation Reduction Act and the Bipartisan

00:43:02.520 Infrastructure Law and the CHIPS Act from the Biden administration of all put large amounts of

00:43:07.860 money out there. And we're beginning to see real progress as a result of deploying those funds.

00:43:13.880 But we still live in a world where the results of the next presidential election could knock a whole

00:43:21.200 bunch of those policies and knock a bunch of that funding out of the arena. And I think for entities

00:43:28.700 that need to make long-term plans, utilities, auto manufacturers, energy producers, it's really

00:43:38.220 important to have a predictable landscape for long-term investments. And I think that without a durable

00:43:46.980 political coalition around action, we'll continue to operate much more slowly than we should. And I think

00:43:55.080 there are some key features of this durable political coalition that we haven't yet tackled

00:44:01.200 with the seriousness that we need to. One is what happens to the individuals and the communities

00:44:09.540 that are negatively impacted by action on climate. What happens to coal mining communities?

00:44:16.360 What happens to oil and gas producing states? What happens to the nations that depend on

00:44:22.160 exporting fossil fuels for their economic viability? And those questions need to be answered

00:44:30.300 in a much more serious way than they have been now. I think there's serious questions about

00:44:36.800 the inequalities and injustices that are introduced by action on climate that need to be dealt with.

00:44:46.240 And there's serious questions about how we're going to think about balancing diverse interests that are

00:44:57.440 aligned on many things, but not perfectly aligned. And one of the cases where we see the kind of

00:45:04.160 challenge that I think is going to be really important for the future and really needs to be solved is

00:45:09.700 is all of the controversy over the siting of offshore wind power installations. Everybody's in favor of

00:45:17.300 offshore wind except where they see the windmills or in favor of utility-scale solar except where it has the

00:45:26.820 potential to alter the migration of a desert tortoise or impact an endangered species. And those concerns are

00:45:36.820 really important. They can't be dismissed out of hand. But we need to figure out some way to make progress

00:45:44.380 around these barriers that are in most cases purely in the human dimension. It's not that we lack the

00:45:52.820 technology or that we don't have the engineering capability to deploy a solution. It's that we haven't

00:46:01.180 not the political and financial landscape laid out in a way that lets us make progress.

00:46:08.740 Well, it seems to me that a lot of the politics is driven by this claim, either implicit or explicit,

00:46:16.180 that the consequences of really transitioning to a low-carbon economy would be economically ruinous,

00:46:24.880 right? It's just way too expensive. Our economy requires continuous growth. I mean, it's really,

00:46:31.720 you know, all of our systems and institutions assume continuous growth. It's really almost a Ponzi scheme.

00:46:39.340 And the renewables really aren't up to the task of providing all the energy we need. There's this piece

00:46:47.420 about nuclear that I'd love you to address because, you know, it seems like nuclear needs to be part of

00:46:54.320 this conversation. And we're really, you know, we really haven't done what we've needed to do to

00:46:59.220 build, you know, new generations of nuclear plants. So there's just, there's sense that it's just too,

00:47:04.840 it'll be too costly to take this message, this imperative, really, to decarbonize seriously,

00:47:13.200 in the, you know, especially in the developed world, you know, places like the United States and

00:47:18.780 Europe. And then when you look at other countries in the developing world or between the developing

00:47:25.560 world and the most developed places, you know, places like India, it seems a species of first world 1.00

00:47:32.180 cynicism to say that they need to be thinking about their carbon footprint when they simply are

00:47:40.420 following the industrial path that we in the developed world followed toward prosperity,

00:47:46.600 right? So we're demanding of them things that we didn't do ourselves. And then there's the question

00:47:51.760 of, you know, how to actually make that demand and incentivize them, you know, appropriately,

00:47:57.340 ethically and politically. So how do you respond to that arguably disjointed set of concerns about

00:48:06.080 just the cost of all of this, both, you know, in the developed world and in the developing world?

00:48:11.980 A few years ago, it was really unclear how we would ever bring emissions of carbon dioxide,

00:48:19.420 especially down to zero. But now there are really clear pathways that combine being equitable,

00:48:30.120 affordable, affordable, reliable, and safe. And I hope it's well known that electricity from

00:48:40.540 photovoltaics is now in almost every part of the world cheaper than electricity from fossil. And we've

00:48:48.280 learned a huge amount about how to integrate large amounts of renewable electricity into the grid

00:48:56.560 and are making really impressive progress in figuring out how to combine renewable sources into a truly

00:49:06.720 reliable system. But there are big problems with what's called intermittency with what do you do when

00:49:15.140 the wind's not blowing or the sun's not shining? And if we were going to deploy expensive lithium ion

00:49:22.260 batteries to be the source of electricity, it would be terribly expensive. But there are a whole bunch

00:49:31.620 of strategies we can use to provide the kind of reliability in the electrical system and in

00:49:40.340 transportation and in manufacturing that we need. One set of options does involve power from sources like

00:49:48.280 nuclear. Nuclear is non-emitting. And we have many countries that are relying on nuclear and have been

00:49:57.300 for decades. There are obviously profoundly important questions about the safety of nuclear, about their

00:50:05.700 connection with weapons proliferation, and about the susceptibility to terrorism. But there's also a lot of

00:50:14.140 progress being made in nuclear. And my personal feeling is that it's important to encourage that progress,

00:50:22.420 even if it turns out that nuclear can't compete on price. And at this point, the impression I have is that

00:50:29.940 nuclear will have real trouble being competitive in most parts of the world because renewables are so cheap.

00:50:37.580 One of the challenges with nuclear is that every increment of extra nuclear power you add to the grid is

00:50:45.360 investment of hundreds of millions of dollars. And it's hard to experiment and try different things when each

00:50:52.500 increment is so expensive. The nice thing about photovoltaics and windmills is that they can scale in tiny little

00:51:01.100 increments. Another feature of the future energy system that we need to think fairly seriously about is

00:51:08.600 continuing to use fossil fuel resources but connect them with carbon capture and storage. We know how to

00:51:17.520 capture carbon dioxide and compress it and pump it into underground formations. That's one of the main

00:51:25.100 techniques we use for extracting oil and gas now. And we know how to run a power plant with

00:51:34.220 CO2 capture. We know how to run a biofuels plant with CO2 capture. And especially at the margins where

00:51:42.160 we're trying to figure out how to provide that last increment of reliability, how we're trying to fill in the

00:51:48.820 gaps where the renewables aren't working. We have lots of potential for using, especially for countries

00:51:57.040 that already have a lot of deployed infrastructure, fossil with CCS. And then an area that I think is

00:52:04.500 incredibly exciting and really has the potential to map out the bridge from where we are now to a

00:52:12.940 system that's fully based on non-technologies involves hydrogen. Currently we make hydrogen from

00:52:21.660 natural gas and the way you make hydrogen from gas is the carbon part of the natural gas goes

00:52:29.280 into the atmosphere of CO2 when the hydrogen gets used. We could capture that carbon and pump it into

00:52:35.960 underground reservoirs. That's often called blue hydrogen. And then we can use the hydrogen to make

00:52:42.160 electricity either by burning it or by running it through a fuel cell. But we also know a lot about

00:52:48.620 how to make hydrogen from electricity by splitting water. That's currently quite a lot more expensive

00:52:55.840 than making it from natural gas, but we're seeing progress there. And once we have large amounts of

00:53:03.300 hydrogen available, we can use that hydrogen as the equivalent of a gigantic unlimited battery and use

00:53:13.100 the hydrogen to make electricity when the sun's not shining, use the sunshine to make hydrogen when the sun

00:53:19.380 is shining. And the pathway that looks to me the most attractive for this transition to a truly

00:53:28.380 non-emitting energy system is to take advantage of our ability to make blue hydrogen now, hydrogen from

00:53:37.160 natural gas, capturing the CO2 so it's a non-emitting. And then as the cost of making hydrogen

00:53:44.760 from sunshine, from electricity goes down, we can transition over to that. It's going to take decades,

00:53:52.020 but that's a pathway that looks at this point like it'll be cheaper than continuing to get energy from

00:53:59.480 fossil fuels. You look across the transportation and manufacturing and electricity spectrum, there

00:54:06.180 are lots of details that need to be worked out and there are some new technologies that are needed,

00:54:11.560 but the new technologies aren't the limiting factor at this point. We have access to a lot of amazing

00:54:20.800 technology now that can get us a long way to the solutions. I'd like to say a couple things about your

00:54:28.120 comment about what should be the timing for the engagement of countries that are not the richest, including

00:54:37.060 countries that are the poorest. And there is a strong motivation that the wealthy countries should be

00:54:46.760 leading the transition. They're the ones that are responsible for the historical emissions. They're the

00:54:53.200 ones that have the economic resources to make the transition. And they also are the ones that have the

00:54:59.960 finances to make it affordable. And as the non-emitting energy sources become the cheapest sources and the most

00:55:09.420 reliable ones, they'll be increasingly attractive in the developing world. With the middle-income

00:55:16.440 countries like India and China that clearly want to be leaders in climate responsive space, there are lots of

00:55:25.860 opportunities for them to invest in new technologies now. But they also will be slower than the richest

00:55:33.960 countries simply as a result of the fact that they don't have the full kind of capabilities that we have. And we're

00:55:41.420 going to need to think really hard about how the rich world interacts with the poor world in terms of driving the

00:55:49.640 energy transition. There are kind of two models you can think about. One is that in the rich world, we make the

00:55:58.140 non-emitting options so cheap that they're the obvious choice. And the other option is that we really rethink what

00:56:07.280 international assistance means and whether financial assistance for accelerating the transition in poorer countries is in the

00:56:17.080 interest of the rich world, because it decreases things like risks of political instability.

00:56:23.520 And we may see some of that. And I suspect that if we see it, it will be in subtle mechanisms like changes in the

00:56:31.180 way that the World Bank or the International Monetary Fund think about their loan portfolios. But one of the things we need to

00:56:40.940 make sure to make sure of, and this is again in the spirit of building durable political coalitions, is that this isn't

00:56:48.400 going to work if the rich world turns to the poor world and says, you folks have to impoverish yourself further by

00:56:58.140 investing resources that you don't have in an accelerated transition.

00:57:02.800 I think there are likely to be decades when the rich world has made tremendous progress, may even have

00:57:14.180 greenhouse gas emissions down to zero, when countries in the poor world will still tend to

00:57:19.700 need to rely on fossil fuels for transportation and electricity generation and manufacturing.

00:57:26.640 And we need to build that into the way we think about what the timing of reaching net zero should be. One of the

00:57:35.020 things that I'm always frustrated at is that when we talk about the Paris compliant time goal being zero emissions by

00:57:43.820 2050, even the richest countries, the richest institutions tend to say, okay, well, I can make a plan to reach net zero by

00:57:55.060 2050. When if everybody needs to reach zero emissions by 2050, the richest actors need to be way ahead of that. And I think we still

00:58:10.160 haven't stepped up to addressing that aspect of the equity challenge.

00:58:15.060 What role does a carbon tax play in this picture?

00:58:18.520 There are lots of ways you could think about incentivizing decreases in emissions. Economists tend to

00:58:26.720 love carbon tax because it really lets the market sort out which approaches are going to be most

00:58:34.620 effective and which are going to be wastes of money. And at least in principle, a carbon tax could be

00:58:43.260 deployed in a in a strategic way that would be globally fair that could really encourage the rapid deployment of the best possible

00:58:53.080 technologies. There are other things we can do. If you look at the history of environmental regulations, we've actually made more

00:59:01.360 progress with command and control approaches than we have with market based approaches. So with the Clean Water Act, the

00:59:11.460 most of the requirements have simply said, you can't put this pollution in the water, or you can't pollute it at a higher level than this.

00:59:19.860 And there's nothing particular to say that a carbon tax would work better than a command and control approach. It really depends on what the politically enabling conditions are.

00:59:34.620 There's been a lot of discussion recently about what's called a border adjustment, where a country with a carbon tax would say, okay, well, any product that is imported from a country that doesn't have a carbon tax has to pay a carbon tax at the border to the country that the product's coming into.

00:59:55.460 And of course, that is a big boost for local manufacturing, as well as for addressing the emissions associated with different products.

01:00:08.020 And, you know, maybe the concept of a carbon tax with a border adjustment will make it more politically palatable.

01:00:15.640 My sense is that in the U.S. we're not very close to agreement on the value of a carbon tax, even though it could, for example, be used to produce a dramatic decrease in income taxes.

01:00:31.160 And I think what's really important is that we come up with something that people can agree on politically and move forward with that and not let the perfect be the enemy of the good, even though carbon tax might be something like the perfect.

01:00:49.540 Finally, what are you expecting here, if you had to guess what path we're going to take through this, the range of possible outcomes in terms of mitigating, failing to mitigate, creating political consensus necessary to mitigate, failing to do that?

01:01:07.960 If you had to guess about what the world is going to look like in 20 years, 30 years, what are you expecting?

01:01:16.900 Well, is there a degree of optimism or pessimism?

01:01:19.540 That's underwriting your current efforts, or are you just agnostic and doing what you feel we need to do in any case?

01:01:27.580 Well, you know, I want to make it clear at the outset that I don't have any special insight into what kind of decision countries around the world are going to make.

01:01:39.140 I am optimistic that the progress that I've seen in the past decade has been really consequential on what emissions levels are.

01:01:52.180 In most of the rich countries, emissions have been decreasing on a year-by-year basis.

01:01:59.280 I think they increased in the U.S. last year, but that was mainly a consequence of the decrease in the COVID pandemic activities.

01:02:07.400 But in most countries, emissions are decreasing.

01:02:09.300 We now live in a world where electricity from renewables is cheaper than electricity from fossil.

01:02:16.280 We live in a world where the most attractive transportation options for private vehicles are electric and where heat pumps can improve the air quality in homes and where we know that pollution from gas stoves is harming people.

01:02:36.360 So, you know, lots and lots of indications that technology is ripe for an accelerated transition, but there's still lots of pushback from vested interests, from oil and gas companies, from fossil producing regions of the world, and lots of need to work on the kind of political coalition that I've been talking about.

01:03:03.180 I expect us to not achieve the very best outcomes, but to make the transition in a way and at a pace that's going to preserve a livable world.

01:03:18.060 At least that's my hope.

01:03:19.200 And what that might mean is that while we don't meet the Paris Agreement goal of stabilizing warming at well under 2C above pre-industrial, we might end up pretty close to 2C, maybe a couple of tenths above it.

01:03:37.000 And there will be incalculable damage associated with not making the goal, but it's a lot better to be at 2 or 2.2 than 3.5 or 4.

01:03:51.200 What do you picture is some of those consequences being necessary just for rhetorical effect to get us politically aligned enough to take this seriously over a time horizon that exceeds the four-year presidential election cycle?

01:04:10.620 It seems to me that to speak locally about the United States in particular, it's so hard for us to make any decision with a time horizon beyond four years politically that it could well take something so noxious and durable as a stimulus for us to say,

01:04:31.120 okay, whatever our political differences, we have to be responding to this year after year after year.

01:04:37.720 You know, this is now a non-negotiable decrease in our quality of life.

01:04:42.700 Are you picturing that being part of the process where it just, you know, take, you know, whatever it is, wildfires or any other stimulus that just becomes so onerous and obscene to be living with these consequences year after year that we just reset our politics around that?

01:04:59.620 Yeah, I have many colleagues who talk about the possibility that truly catastrophic extreme event, a Category 5 hurricane hitting Miami or the kind of mega heat wave that Kim Stanley Robinson describes in Ministry for the Future.

01:05:19.480 And it's possible that one of these truly catastrophic events will galvanize national and world opinion.

01:05:29.860 My expectation is that it'll probably be a little more incremental than that, that the non-emitting technologies will continue to be cheaper and better and more attractive in the marketplace,

01:05:45.220 that an appreciation that the climate change needs to be addressed will get nailed down with each wildfire and each extreme precipitation event,

01:05:56.560 and that we'll just gradually transition to a much stronger focus on making progress in this than we have to date.

01:06:08.120 And I think that a lot of that is going to be dependent on having this be a world in which there are opportunities for the kinds of individuals and actors that are not seeing opportunities now.

01:06:24.120 And that's going to be things like energy producing states, oil and gas companies, individuals who currently work in manufacturing or energy production.

01:06:37.640 And I just want to close with the thought that until we're really serious about these interests that are displaced by progress on climate,

01:06:50.340 it's going to be really, really hard to come up with the kind of broad political coalition that we need.

01:06:56.980 And we'll go more slowly as a result of not building out that coalition.

01:07:02.680 Well, Chris, thank you for the tour of the possible apocalypse.

01:07:08.560 I feel much better educated and strangely more optimistic for having spoken with you.

01:07:13.640 So thanks for what you're doing and thanks for bringing your voice here on the podcast.

01:07:18.500 I enjoyed the conversation. Thanks so much.

01:07:20.740 I enjoyed the conversation.

Making Sense - Sam Harris - September 05, 2023

#333 — Sanity Check on Climate Change

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