0:21

Welcome to the Making Sense podcast. This

0:23

is Sam Harris.

0:26

Today I'm speaking with Chris Field. Chris

0:29

is the director of the Stanford Woods Institute

0:32

for the Environment and the Melvin and

0:34

Joan Lane Professor for Interdisciplinary Environmental

0:36

Studies at Stanford University. Prior

0:40

to his appointment at the Stanford Woods Institute,

0:42

Chris was a staff member at the Carnegie

0:45

Institution for Science and

0:47

founding director of Carnegie's Department of

0:49

Global Ecology. Chris's

0:51

research has focused on climate change.

0:54

He is a

0:55

very influential scientist in the field,

0:58

widely cited. He's

1:00

especially focused on solutions that improve

1:02

our lives now and decrease the

1:04

amount of future warming.

1:06

He's been deeply involved in the national and international

1:09

efforts to advance our understanding of global

1:11

ecology and climate change.

1:13

Chris has also overseen many of the efforts of the

1:16

Intergovernmental Panel on Climate Change,

1:18

as you'll hear.

1:20

He's also been elected to the US National Academy

1:22

of Sciences, the

1:23

American Academy of Arts and Sciences.

1:26

He's received the Max Planck Research Award,

1:29

among others. He

1:31

holds a bachelor's degree in biology from Harvard

1:33

and a PhD in biology from Stanford.

1:36

Anyway, I wanted to get Chris on the podcast because I

1:38

wanted a sanity

1:40

check, frankly,

1:42

about climate change.

1:44

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

1:47

We are now in a political season

1:49

where Republican candidates for the presidency

1:52

can be heard saying things like the climate

1:54

change agenda is a hoax. So

1:56

I just wanted to get a top-flight

1:59

research scientist. here to

2:01

articulate what the mainstream

2:04

scientific consensus is

2:06

on climate change,

2:07

our contributions to it, the promise

2:10

of mitigating it, what the future is

2:12

likely to look like, etc. Obviously

2:15

this is another PSA, so no

2:17

paywall, but if

2:19

you want to support the podcast, the way

2:21

to do that is to subscribe at

2:23

SamHarris.org,

2:25

which makes all of this possible.

2:28

And now I bring you Chris Field.

2:35

I am with Chris Field. Chris,

2:37

thanks for joining me. It's my pleasure,

2:39

thank you.

2:41

So we're going to talk about climate change,

2:43

what we know about it, what we don't know about

2:46

it, what many of us refuse to know about

2:48

it, but first describe

2:50

your background. What work have you done

2:53

on this issue?

2:54

My degrees are in biology, but

2:57

when I started my academic career, I

2:59

turned really right at the outset

3:02

to trying to understand big-picture

3:05

issues of how global change

3:08

was altering ecosystems, altering

3:11

biological diversity, altering plant growth,

3:14

and just changing the natural

3:16

world. Most of my early

3:19

work in this space was experimental

3:21

and spent several decades

3:24

doing experiments, especially at Stanford's

3:26

Jess Bridge Biological Preserve, where

3:28

we altered the environmental conditions

3:30

for entire chunks of

3:32

grassland ecosystems. We changed

3:35

the concentration of carbon dioxide in the atmosphere,

3:38

we changed the amount of rainfall, we

3:40

changed the temperature that

3:42

the ecosystems were going into, and had a

3:44

front-row seat for looking at what

3:47

happened to ecosystems when they were exposed

3:49

to the kind of climate conditions

3:52

that we expect in the future.

3:54

In parallel with that work, my

3:56

group started doing assessments

3:59

of what we know about what's happening with

4:01

the global carbon cycle and, in

4:04

particular, why ecosystems

4:07

on land have been so successful

4:10

at taking up a large fraction

4:12

of the carbon dioxide that's emitted from

4:14

fossil fuel combustion. That

4:17

work led to a

4:18

whole bunch of different characterizations

4:21

of plant growth across

4:23

the entire biosphere, covering

4:25

not only the land, but also the oceans.

4:28

Around the time we started doing these global

4:30

scale synthesis,

4:31

I also got involved in the Intergovernmental

4:34

Panel on Climate Change and

4:37

found that just a wonderful opportunity

4:39

to broaden my understanding and my perspective.

4:42

So for the IPCC fourth assessment

4:44

report, I was what they call the coordinating

4:47

lead author, the person in the crosshairs

4:50

for the chapter on North America,

4:52

where we tried to assemble basically

4:54

everything that's known about climate

4:56

change impacts expected on North America,

4:59

what we can do to adapt, who's vulnerable,

5:02

and who's not. And then for the

5:04

IPCC fifth assessment report, which

5:07

was published in the 2013-14 timeframe, I served as the

5:09

co-chair, again, the

5:10

person in

5:15

the crosshairs for the whole report

5:18

on

5:18

impacts, adaptation, and vulnerability, and really,

5:21

again, had the bird's eye view

5:23

of everything that we know about climate change

5:25

impacts around the world. Since

5:27

the IPCC era, which really for me

5:29

ended in around 2014, I've been focusing

5:32

on

5:32

climate change

5:37

solutions,

5:38

natural climate solutions, how we can take better

5:40

care of our soils and forests

5:43

and oceans,

5:44

and on technology-based solutions,

5:46

how we can more rapidly transition

5:49

to an energy system that doesn't

5:51

emit greenhouse gases.

5:53

And what's your current position at

5:55

Stanford? Well, my main

5:57

job is that I'm director of the

5:59

Stanford Woods Institute for the Environment.

6:03

And for

6:04

nearly two decades now, the Woods Institute

6:06

has been

6:08

incentivizing members of the

6:10

Stanford community, faculty, students,

6:13

neighbors, to be involved

6:15

in interdisciplinary solutions-oriented

6:19

research about

6:20

critical environmental issues,

6:22

issues involving climate, food, water,

6:25

health, the oceans. And

6:29

it's been a wonderful opportunity

6:31

to build bridges between researchers

6:33

to help people observe

6:36

and discover new aspects of their work,

6:39

and to really

6:41

push the frontiers. And what

6:44

I think of as laying the foundations

6:46

for Stanford's bold new

6:49

investment in the Stanford-Dor School

6:51

of Sustainability. Hmm.

6:53

John Dorr gave a very big grant to Stanford,

6:55

didn't he? A large gift, a

6:57

transformational gift, and it's one that

7:00

I am confident is really

7:03

propelling Stanford not only to the front ranks

7:06

of university, but to the front ranks

7:08

of leading progress in tackling the climate crisis.

7:11

Well,

7:11

I want to talk about the science

7:13

and

7:14

the mitigation solutions. And

7:17

really, I just want to track through

7:19

all that we know about this. But I

7:21

want to start

7:22

with some of the skepticism

7:25

that all of us perceive certainly right

7:27

of center on the political landscape.

7:30

And so if you're just

7:32

a consumer of media at the moment,

7:34

the moment you tack right

7:37

of center, you meet

7:39

a

7:39

fairly pervasive concern

7:42

that

7:43

our climate problem

7:45

has been overblown, right? There's

7:47

this sense that there's this new catastrophism,

7:50

there's an anti-capitalist

7:52

agenda,

7:53

there's a new religion of fear and guilt

7:56

complete with its priests.

7:58

And we have for all intents and purposes

8:01

what appears to be an emotionally

8:03

vulnerable teenager serving

8:06

as a Joan of Arc character for

8:08

this movement. And I'm

8:10

referring of course to Greta Thunberg.

8:12

And the optics of

8:14

all of this, whatever good that has

8:17

accomplished, real or imagined, on

8:19

the left, on the right, the optics

8:21

are quite a bit different. And as

8:24

far as I can tell, many skeptics seem

8:27

to believe at this point that they're on very firm ground

8:29

in saying that our models for climate

8:31

change going back decades

8:33

have been basically wrong.

8:35

So I want to start there. How have our models

8:40

looked

8:41

and to what degree have they been born out over

8:43

the last 30 or 40 years since we've

8:45

been

8:46

articulated in them? What

8:48

if anything have we been wrong about up until this

8:50

point and just

8:52

how solid has the story

8:54

become

8:56

in recent years?

8:57

Let me start out with a brief

9:00

comment about the history of

9:02

skepticism about climate change.

9:04

And as Naomi Oreskes

9:07

has documented in her really

9:09

brilliantly researched book, the

9:12

history of skepticism has

9:14

deep roots in interests that have

9:17

been opposed to transitioning away

9:20

from fossil fuels. But it really got

9:22

going in an era

9:24

when we really

9:26

couldn't concretely

9:29

document that the climate was

9:31

already changing as a consequence

9:33

of human actions.

9:35

Back in the 1980s

9:37

and the 1990s, we had a solid theoretical

9:39

understanding of where

9:43

we

9:46

were headed. We could certainly see the concentration

9:48

of greenhouse gases in the atmosphere

9:51

increasing. And it was getting

9:53

warmer, but it wasn't getting warmer

9:55

in a way that was right in

9:57

your face for people around the world. We

9:59

all

9:59

also weren't seeing dramatic

10:02

changes in the

10:04

frequency or severity of extreme

10:06

events.

10:07

And since about 2010,

10:10

that's really dramatically changed.

10:12

And

10:13

almost everyone has a personal

10:15

experience

10:16

with the fact that

10:19

the climate is different now

10:21

than it was only a few years ago.

10:24

Many more heat waves, many

10:26

more examples of heavy precipitation,

10:29

the exact kinds

10:31

of things that the climate science community

10:33

has been predicting for

10:35

decades are really playing out in real

10:38

time. And

10:39

if you look at the predictions

10:42

from,

10:42

for example, the IPCC, what you see is

10:46

that the

10:48

central forecasts of where

10:51

we would be with temperatures

10:53

in the 2020s that the IPCC made

10:56

in 1990 were

11:01

bang on. There really hasn't

11:04

been any systematic

11:07

problem with any of the calculations.

11:10

And it's important to understand why this is.

11:13

The fact that carbon dioxide,

11:15

greenhouse gas, has been understood

11:18

since the middle of the 19th

11:20

century.

11:21

In 1896, the brilliant Swedish

11:24

chemist, Svanti Arrhenius, published a paper

11:26

where he knew in 1896 that

11:29

the three things you need to do to make

11:31

an accurate forecast

11:34

of how much increasing CO2 changes

11:36

climate.

11:37

He knew that carbon dioxide is a greenhouse gas.

11:40

He knew that a warmer

11:42

atmosphere will hold more water vapor and that

11:45

increase in water vapor will amplify

11:47

the warming effect of the carbon dioxide.

11:50

And he knew that over the course

11:52

of several decades, CO2 that's added

11:54

to the atmosphere gradually partitions

11:57

between the atmosphere and the oceans so that

11:59

eventually,

11:59

about 80% of it ends up in the

12:02

oceans.

12:03

With those three things, he was able

12:05

to make a back of the envelope

12:07

calculation of how much warming we'd expect

12:10

with a doubling of carbon dioxide. He

12:12

didn't get exactly the right answer, but it was pretty

12:15

darn close. And that was,

12:17

what, 127 years

12:19

ago. And

12:21

in that 127 years, the sciences

12:24

only gotten more and more solid

12:26

on those

12:27

foundational elements and

12:30

on the interactions that

12:33

mean that the actual outcomes might be

12:35

somewhat worse or somewhat less bad in particular

12:38

locations. So, I mean, one

12:40

problem here, it seems to me, is that the

12:42

magnitude of the change

12:44

just doesn't sound that

12:47

bad to most people. I mean, anyone who's steeped

12:49

in the science,

12:50

as we're going to show here,

12:53

learns how to interpret

12:55

these numbers. But, if you just told

12:58

me in

12:59

my naive state that 30 years

13:01

from now, my children would be living in a world that

13:03

is on average three degrees Celsius warmer

13:06

than it is now, it's not immediately

13:08

obvious

13:09

why that would be such a bad thing. I mean,

13:11

if you don't like the heat, you can move a little north.

13:14

Yes, some people are going to... Turn on the air conditioner.

13:16

Yeah. Some people are going to lose their beach houses when

13:18

the sea levels rise.

13:20

Life in Bangladesh isn't going to be so great, but

13:22

life in Bangladesh has never been so great.

13:25

So, it's easy for people to just log

13:28

this whole concern

13:30

as nothing more than a hypothesis

13:33

and the knock-on effects of these

13:35

global mean temperature changes

13:37

are at

13:40

best speculative and sort

13:42

of hard to worry about. How would

13:45

you address that intuition? Well,

13:47

there are a bunch of elements to

13:49

the narrative that you just spun

13:52

out. The first is that a

13:54

small amount of warming, particularly when described

13:57

in Celsius degrees, doesn't sound like

13:59

much. And I

14:02

think it's useful to talk in

14:04

Fahrenheit degrees, where each Fahrenheit degree

14:06

is, of course, 1.8 Celsius degrees

14:08

and makes it clear that

14:11

these are real numbers. They're easy

14:14

to measure. And I think what

14:16

is probably the most

14:19

important fact for

14:22

people to understand is that an average

14:25

warming of 2 or 3

14:27

or 4 degrees Fahrenheit is

14:30

not going to be existential

14:32

for most people in most places

14:34

around the world. But the increase

14:37

in the frequency and the intensity of extreme

14:40

events

14:40

has the potential to be the

14:42

kind of extreme heat that we saw

14:44

in Phoenix this summer, for example,

14:48

or the kind of heavy

14:50

precipitation that we saw with the devastating

14:52

floods in Pakistan. Last year,

14:55

those are good examples of the

14:58

kinds of events that we have. High

15:00

confidence are connected with

15:02

warming. And we know that

15:06

not only

15:07

with a warmer climate

15:09

do we automatically

15:11

see more extremes just

15:13

because we've shifted the center

15:16

of the distribution of climate outcomes,

15:18

but we also know that a

15:20

warmer climate

15:22

has mechanisms that are making it

15:24

more variable.

15:26

So those two things really

15:29

push us into a situation where

15:32

we're really spending a huge amount

15:34

of time and effort and Monday preparing

15:37

for extreme events and coping with

15:39

the consequences of extreme events. But

15:42

I

15:42

do want to address another aspect

15:44

of your question about the

15:47

sense of overplaying the catastrophic

15:50

consequences. And

15:52

I don't think you see that from the

15:54

scientific community,

15:56

but there are lots of descriptions

15:58

in the public narrative that

16:02

over-dramatize the

16:05

kinds of impacts that we can expect, particularly

16:08

if we do a good job of tackling

16:10

climate change and limiting warming

16:12

to something like the goals of the

16:15

Paris Agreement,

16:16

well under 2 degrees Celsius or

16:18

about 3.5 degrees Fahrenheit. If

16:23

we can be successful at

16:25

limiting the warming to that

16:28

range,

16:29

we'll see impacts that are

16:31

existential for some regions,

16:34

low-lying islands, coastal

16:36

areas around the world. Many

16:38

people will die unnecessarily

16:40

as a result of the

16:43

exposure to high temperatures or

16:46

being caught in a wildfire

16:48

that's climate-stimulated.

16:50

But those aren't conditions that are likely

16:52

to be

16:53

existential for humanity

16:56

or for society or for the global

16:59

economy.

17:00

They're conditions that we should be avoiding because

17:02

we have the potential to do that.

17:05

It's smart, it's affordable,

17:08

and it will provide

17:10

a better quality of life for citizens

17:12

around the world.

17:13

But that's different than saying,

17:16

unless we drop everything

17:18

and focus solely on climate

17:21

tomorrow, civilization will

17:23

disappear at any given date.

17:26

This is a complicated,

17:29

important,

17:30

critical-to-address problem

17:33

because it has lots of leverage on the future, not

17:36

because

17:38

we're on the edge

17:40

of a precipice

17:41

that's likely to be civilization ending.

17:59

climate change. It's just a very

18:02

straightforward claim that this is

18:04

evidence of climate change. This is a consequence

18:07

of our irresponsibility

18:09

on this issue. And so we have fires in Canada

18:12

and Greece and recently Maui

18:14

raging to great effect

18:17

and with attendant

18:19

loss of life and massive amounts

18:21

of pollution.

18:22

But then I read in the Wall

18:24

Street Journal

18:26

that this is really just

18:28

false reporting that

18:31

this is much more of a story of failures

18:33

of forest management and fire control

18:35

and even arson. And

18:39

in fact, the percentage of

18:41

the earth that burns each year has declined

18:44

steadily since 2001. So the last

18:47

two decades has not been a story of

18:50

increased wildfire

18:52

consequence globally. In

18:54

fact, there's been a reduction there. So

18:57

again, this is just the

18:59

muddled message of what is real.

19:01

Well,

19:02

wildfires, critically

19:05

important issue, horrendous

19:06

impacts

19:08

on the affected communities. Heartjust

19:11

has to go out to the people

19:13

of Maui,

19:14

Paradise, Santa Rosa, all the communities

19:17

that have been affected. And

19:19

the wildfire story has a whole bunch of different

19:22

pages. It is certainly true

19:25

that the global

19:27

area

19:29

burned in wildfires has gone down consistently

19:31

over the last couple of decades. That

19:34

is entirely a story of

19:36

African savannas,

19:38

three quarters of the global area that

19:40

burns every year burns

19:41

in African savannas. Those are

19:43

mainly

19:44

related to agricultural practices

19:46

and rangeland management.

19:49

And those practices have been changing. At

19:51

the same time, if you look at regions

19:54

like the Western United States,

19:56

but dramatic increase in

19:58

area lost in. wildfires.

20:00

And we've seen that

20:02

in many regions of the world, including

20:05

the Mediterranean and

20:06

in Australia.

20:08

Okay, sorry. So there's been an increase

20:10

in the Mediterranean and Western North America, but

20:13

there's been a massive decrease in Africa.

20:15

Africa. Okay. In Africa. And

20:17

the African fires are

20:19

almost entirely savannah fires,

20:21

grassland fires. And of course, the

20:24

consequences for recovery

20:27

for the global carbon cycle are much

20:29

different for these grassland

20:32

and savannah fires than they are for forest

20:34

and chaparral fires like we have in North

20:37

America.

20:38

But it also is true that

20:41

there are a number of factors

20:44

that have contributed to the

20:47

increase in fire risk in many

20:49

of these fire-prone ecosystems.

20:52

In Western North America, we

20:55

know that decades of fire suppression

20:58

allowed the accumulation of large

21:01

amounts of highly flammable material.

21:04

And we know that in Western

21:06

North America, there's been a huge influx

21:09

of people into what

21:11

we often call the wildland-urban interface,

21:14

but into forested regions that are

21:16

susceptible to wildfire.

21:18

And those two factors, when

21:21

coupled with the increased

21:24

tendency for these forests

21:26

to generate unmanageable

21:29

conflagrations as a result of

21:31

climate change, has really changed the picture.

21:33

And in Western North America,

21:35

especially in California,

21:37

we really have seen a transition

21:40

from

21:40

fires that were

21:44

manageable in a kind of professional

21:47

fire sense, even though occasionally

21:49

they had devastating consequences to

21:51

fire behavior that's really unprecedented.

21:54

And it has resulted in a huge

21:57

increase in the area burn. And frustrating

22:01

and devastating increase in loss

22:03

of lives in wildfires. And

22:05

with any particular fire, it's hard

22:08

to know what the contribution

22:10

of climate change was until it's been

22:12

thoroughly evaluated. I think with

22:14

the fires in Maui, we still don't

22:17

have a clear picture.

22:19

Okay, so let's track through this somewhat systematically

22:21

here. And what I'd like you to do is

22:24

demarcate what is totally uncontroversial

22:27

from a scientific point of view from

22:29

the gray areas because

22:32

in so far as there's a through line here

22:35

that is analogous to the claim

22:37

that smoking is bad for your health,

22:39

something that's totally non-debatable at this point

22:42

in medicine,

22:43

I want us to keep that in view. And

22:45

then when we wander off of that level of

22:48

certainty, I'd like us to flag

22:50

it.

22:51

So just to begin with,

22:53

how are global temperatures

22:56

measured?

22:57

How are we getting this data?

23:00

And

23:01

what if any are the main

23:03

sources of uncertainty with

23:05

respect to the measurements and

23:07

the models we're developing as a

23:09

result of them?

23:11

We have a really accurate

23:13

record of global temperatures

23:16

going back to the latter

23:18

decades of the 19th century, around 1880.

23:21

We had a sufficient number

23:24

of

23:25

carefully instrumented

23:27

and observed

23:29

weather stations and ocean observations

23:31

to be able to develop high

23:35

confidence record of global

23:37

temperatures. And that

23:40

core record, which is now maintained

23:42

in a bunch of different research institutions,

23:45

is based on tens

23:47

of thousands of thermometers,

23:51

their

23:51

millions of ocean observations,

23:54

and just an incredibly

23:57

carefully curated. record.

24:01

And

24:01

there's been a huge amount of scholarship

24:04

in

24:04

figuring out what

24:08

happens when the area

24:10

urbanizes around a weather station

24:12

and there are gaps

24:14

in the record. And all of that has been

24:17

really super carefully filtered

24:20

out

24:21

so that the different groups that are

24:23

doing the analysis, including one

24:25

really prominent group that's

24:27

based at UC Berkeley and started out

24:29

to prove that the instrumented

24:33

temperature record wasn't all that great, ended

24:35

up demonstrating that it was spectacularly

24:39

good. And they got exactly the same thing

24:41

as

24:42

NASA and the UK Met Office

24:44

and the other groups that are doing the temperature

24:46

records. So we have

24:48

basically thermometers that

24:50

have been deployed around the world and

24:53

measuring

24:54

temperatures of air and ocean water

24:56

for about 140 years.

24:59

And those are increasingly

25:02

augmented with

25:03

satellite data. For

25:05

a while, there was a thread

25:08

running through the skeptical

25:12

climate science literature that the

25:15

satellite data wasn't showing the same amount

25:17

of warming that we were getting with

25:20

surface observations and that there

25:22

must be something wrong with surface

25:24

observations.

25:26

But it turns out that once the

25:29

orbital dynamics of the satellites

25:31

were

25:32

understood and appropriately

25:34

corrected,

25:35

that the temperature record from the satellites

25:37

is

25:38

essentially identical to the temperature

25:40

records from the thermometers.

25:43

So we now have not only

25:45

these instrument records and the

25:47

satellite records, but we have literally

25:51

tens of thousands of different kinds

25:53

of

25:54

ecosystem markers that are telling

25:56

us the same thing.

25:57

We have things like flowering dates

25:59

of data.

25:59

different plants. We have the

26:02

hatching nesting

26:04

dates of birds.

26:05

And these observations around

26:08

the world

26:09

really paint exactly the same picture.

26:11

A picture where we have seen

26:13

to date a

26:15

warming of a little more than

26:18

one Celsius, about two degrees

26:20

Fahrenheit

26:22

over the last century, and a warming

26:24

that has

26:25

rapidly accelerated since

26:27

around 1990.

26:31

How do we differentiate the natural

26:34

climate variability from

26:36

human-induced change? Obviously,

26:39

the climate has changed over its

26:41

history, and we have some record of that.

26:43

And I guess

26:45

I could also add the

26:47

question here, how do current

26:50

CO2 levels compare to historical

26:54

levels?

26:55

Do we actually think we know the percentage

26:57

of change that is human-induced at this point?

27:00

In the CO2 concentration

27:02

and in the temperature, we have a good record

27:04

of both. So this

27:07

question of what the historical variability

27:09

will look like, of course,

27:12

is quite different if you look on

27:14

different timescales.

27:16

We have good

27:18

records of temperature that we

27:20

can extend back the

27:23

order of a thousand years based

27:25

on something that feels like instruments,

27:29

and we can have high confidence

27:31

that the instrumented

27:33

temperature is now the highest it's been

27:35

in the last thousand years or based on

27:38

that.

27:38

We also have

27:40

really excellent temperature proxies

27:43

from ice cores that

27:45

have been extracted from the Greenland

27:47

ice sheet or from alpine glaciers around the

27:49

world, or from the

27:50

Antarctic ice sheet.

27:53

And depending on the resolution

27:55

one wants, we can get

27:57

annual resolution back. thousands

28:00

of years from the Greenland ice sheet

28:03

or

28:03

almost a million years from the Antarctic

28:06

ice sheet. And across

28:08

all those records, what

28:10

we can see is that there

28:13

have been periods when the climate

28:15

was very different than it is now. There

28:17

was a period around 7,000 years ago that was

28:20

comparably warm to what we're seeing now. And

28:23

there have been many periods when the climate

28:26

was substantially colder, ice

28:28

ages, over the last several

28:31

million years. And we understand a lot

28:33

about what's causing those. In fact, some

28:35

of the best evidence that

28:38

carbon dioxide drives changes in climate

28:41

comes from reconstruction

28:43

of what happened during the ice

28:46

ages that the earth has gone through

28:48

for

28:49

the last several million years and for which we

28:51

have these really good ice core temperature records

28:53

for about the last 800,000. And you said we've experienced slightly

28:56

over a

28:59

degree Celsius

29:02

increase in mean global temperature

29:04

over the last century, so just shy

29:06

of two degrees Fahrenheit. Is that right?

29:09

Yes, right around two degrees

29:11

Fahrenheit.

29:12

And as far as the models predictions

29:15

from here, what is

29:17

predicted and are there competing models? How

29:19

much variance is there between

29:21

models or is there a real

29:24

convergence with respect to

29:26

the scientific picture here as far

29:28

as

29:30

the possible range of

29:32

temperature increase we can expect, I

29:34

guess

29:35

bounded by the

29:37

most aggressive, conceivable mitigation

29:40

strategy versus our just

29:42

living in a business as

29:44

usual,

29:45

racing toward the brink style

29:48

of increased industrialization

29:50

and zero mitigation. What's expected?

29:54

What we know now

29:56

is that the biggest source of

29:58

uncertainty and

30:00

decades ahead is what we

30:02

do.

30:03

And there's a huge difference between

30:05

a

30:06

world of ambitious mitigation

30:08

where greenhouse gas emissions are

30:11

tackled aggressively, brought down to zero,

30:13

and the

30:14

greenhouse gases already in the atmosphere

30:16

are removed,

30:17

and the

30:19

opposite a world of continued

30:22

high emissions where countries,

30:25

companies, individuals decide

30:27

that they're not going to tackle the problem

30:29

and

30:30

continue to invest

30:32

heavily in

30:34

infrastructure and utilization of

30:37

fossil energy, of emissions-intensive

30:39

agricultural

30:41

techniques, and clearing a forest.

30:44

And

30:44

with the most ambitious

30:48

conceivable actions, we

30:51

can

30:52

limit warming to

30:54

somewhere in the range of one

30:56

and a half to

30:58

two C. The Paris agreement

31:00

says we're committed to limiting

31:02

warming to well under two degrees Celsius.

31:05

And in the world

31:08

of continued high emissions,

31:11

we might see a global average temperature

31:14

in 2100

31:14

between

31:17

four and five degrees Celsius warmer

31:19

than pre-industrial.

31:21

Now, one really dramatic,

31:24

amazing, and encouraging sign

31:27

is that 10

31:28

years ago, it looked

31:30

like we were on a trajectory

31:33

to be in this world of continued

31:36

high emissions in the

31:38

IPCC literature. It's called

31:41

RCP 8.5 representative

31:43

concentration pathway with eight

31:46

and a half degree watts per square meter

31:48

of additional climate heating,

31:52

and that was

31:53

designed as a

31:55

picture of a world

31:58

where there were no constraints

32:01

on using fossil fuels,

32:02

no particular progress in

32:05

limiting them,

32:06

and no real effort to turn

32:08

away from a high emissions lifestyle.

32:12

When we look now, we're

32:14

headed in a kind of a most

32:17

likely outcome. The

32:19

estimates range from this Paris

32:22

compliant, 1.5

32:24

to 2C to

32:27

more like 3C globally.

32:30

That's a dramatic progress. In

32:33

some sense, you can say, wow, we've

32:35

already solved maybe 25%

32:38

or maybe even a third of

32:43

the total climate problem

32:45

as a result of technological progress

32:48

and policies that

32:51

have been implemented in

32:52

the last decade or so. And it is

32:55

really remarkable progress. And it's

32:57

in

32:57

documentation that

33:00

meaningful change can come

33:03

from modest deployment of

33:05

things that we already know how to do and

33:07

are affordable.

33:08

I think that that's in many ways

33:10

the undersung triumph

33:14

of the transition to a

33:16

sustainable world is that we have

33:19

moved dramatically away from

33:21

this RCP 8.5

33:23

world of continuing high emissions. Well,

33:26

I want to talk about the details of

33:29

what it would take to transition further

33:31

into a low carbon economy.

33:34

But before we do that, let's talk

33:36

about some of the feedback mechanisms

33:39

here because

33:40

some of them are pretty surprising

33:42

and even perverse. For

33:45

instance,

33:46

water vapor is a greenhouse

33:48

gas and yet certain

33:50

forms of air pollution have

33:53

a net cooling effect. So,

33:55

do we want less water vapor and more

33:57

sulfur dioxide and soot in the atmosphere?

33:59

I mean, it's just a, actually,

34:02

there was a piece published in the New York Times

34:04

today

34:05

citing, I believe, a paper in Nature from,

34:07

I think, last year that claimed

34:10

that without all of our industrial air

34:12

pollution over the last century, the

34:14

temperature increase would have been 30

34:17

to 50% higher, right, because

34:19

all of these

34:20

polluting aerosols

34:22

exert this cooling effect by reflecting

34:24

sunlight back into space. And

34:27

yet, we know that air pollution, it's

34:29

estimated, kills around 10 million people

34:31

a year, right? So air pollution is

34:33

a major concern in its own right. And it's also

34:35

true that the air pollution and the greenhouse

34:37

gases are produced by the same behavior,

34:40

but it's just, there's this perverse fact that

34:42

if we just got busy

34:44

cleaning up the pollution side of

34:47

it,

34:47

we could expect more warming.

34:50

And it just seems like a terrible outcome.

34:52

And it even has, I think,

34:54

locally concentrated implications where

34:57

if you really clean things up in India,

34:59

say,

35:00

India would experience extreme

35:03

heat events even worse than

35:05

they

35:06

otherwise would.

35:07

Can you talk in general, I mean, feel free to address

35:10

that specific case, but

35:12

can you talk in general about what we know

35:14

about

35:15

feedback loops in

35:17

the climate system and

35:19

how they complicate

35:21

the picture here?

35:23

It's important to recognize

35:25

that there are many

35:28

climatically active substances. Water

35:31

vapor is a powerful greenhouse gas. And

35:35

the effect of extra

35:38

water vapor that stays

35:40

in the atmosphere as a consequence of warming

35:43

from carbon dioxide is really

35:45

substantial.

35:47

It amplifies the

35:49

warming from CO2 by more than

35:51

half.

35:52

But it's not like we can regulate

35:54

that.

35:55

The amount of water in the atmosphere is controlled

35:58

by the

35:59

temperature. the air, a warmer atmosphere

36:01

holds more water vapor and there are

36:04

vast areas, 70% of the earth is

36:06

ocean, and the water

36:09

is freely evaporating into the atmosphere. And

36:11

so

36:12

you can think about it as

36:15

kind of vicious cycle feedback that the more

36:17

CO2 is in the atmosphere, the warmer it is,

36:20

the more water vapor the atmosphere will hold, and

36:22

then it makes it warmer still.

36:24

So water vapor is

36:27

simply a part of the system that

36:30

amplifies the effect of carbon dioxide.

36:33

There's one important

36:35

wrinkle on that and it's that

36:38

water vapor doesn't

36:40

get very much into the upper

36:43

layers of the atmosphere, the stratosphere. And

36:46

one of the reasons that the

36:49

emissions from

36:51

jet airplane travel are so

36:54

important for climate is that jets

36:56

deliver a substantial amount of water

36:58

to the stratosphere where

37:00

it has this warming effect and stays

37:03

in the atmosphere longer

37:04

than it would if it was at lower

37:07

elevations.

37:08

Water vapor, super interesting,

37:10

important, and except for the wrinkle

37:12

about jet airplane travel

37:15

is not a lever

37:18

about climate that we can control, but

37:20

we are always going to see this amplifying

37:22

effect of water vapor.

37:25

Air pollution aerosols

37:27

have the effect

37:30

in general of reflecting

37:33

sunlight back into space, resulting

37:36

in

37:37

conditions that are cooler than they

37:39

would otherwise be.

37:41

But air pollution aerosols

37:44

are

37:44

devastating for human health around

37:46

the world. Millions of people every year die as

37:49

a result of exposure to air

37:51

pollution. And a

37:53

critical priority

37:55

for environmental action is to find a way to

37:57

decrease this pollution, wreck it, and then get it back to the environment.

38:00

Recognizing that if

38:02

we were dramatically successful

38:05

at decreasing levels of

38:07

aerosols,

38:09

we would end up with

38:11

climate conditions that were

38:13

substantially warmer in some

38:16

places.

38:17

And it is also

38:19

the case that the aerosol

38:22

effects tend to be quite local

38:24

because the

38:26

lifetime of most

38:28

of the pollutant aerosols is for

38:30

a short few hours to a few days

38:33

as opposed to centuries for

38:35

carbon dioxide.

38:37

With carbon dioxide, the climate effects are

38:39

felt everywhere. Aerosols tend

38:41

to be much more local. So

38:44

that means that, as is the

38:46

case for a water vapor, that their

38:48

aerosols don't make the job

38:51

easier, but they still

38:54

point a path to a solution. How

38:56

we need to clean up

38:58

the air pollution that's responsible

39:00

for all these deaths. And

39:02

the biggest problem areas

39:05

are emissions from coal-fired

39:07

power plants and emissions from diesel

39:09

engines. We know how to address

39:12

both of those with renewable energy to

39:14

make more progress.

39:16

And we need to recognize that as

39:19

we do that, we'll save millions of lives,

39:21

but we'll have to work harder and faster

39:23

on decreasing emissions of greenhouse

39:26

gases

39:27

because the aerosols have

39:29

been hiding some of the greenhouse

39:31

gas effect. Let

39:34

me mention one other aspect

39:37

of aerosols that people are increasingly

39:40

beginning to discuss.

39:42

We know from observations

39:45

of air pollution aerosols, from power

39:47

plants and stuff, and especially from

39:49

historic

39:50

volcanic eruptions,

39:53

that injections of large

39:55

amounts of aerosols into the stratosphere

39:58

elevations of 12

40:01

to 20 miles above the surface

40:04

can

40:05

produce a significant cooling

40:07

of climate.

40:08

The Philippine volcano Pinatubo

40:11

that erupted in 1991 resulted in a global cooling

40:13

of

40:14

nearly

40:17

one degree Fahrenheit

40:20

for about two years as a

40:22

result of

40:23

putting large amounts of

40:26

sulfur dioxide into the stratosphere.

40:29

Producing aerosols reflected sunlight

40:31

and cooled the planet.

40:33

And there have been many calls

40:36

for exploration of whether

40:40

we might want to use this. It's

40:42

often called solar geoengineering or

40:44

solar radiation management

40:46

to

40:48

prevent some of the warming

40:50

from occurring,

40:52

even at the same time we're recognizing

40:54

that that's not a comprehensive solution

40:56

to climate change. The

40:59

idea of injecting, essentially,

41:01

air pollution into the stratosphere

41:04

is that

41:05

that's a part of the atmosphere. We're not

41:07

primarily influencing

41:10

people's health.

41:11

Because

41:13

of the way the atmosphere works, material

41:16

in the stratosphere stays there for

41:18

one to two years. And

41:20

the quantity that you would need in

41:23

order to have a significant effect on climate would

41:25

be much less than the quantity that

41:28

would have the same effect closer

41:30

to the surface. Is there much energy

41:32

behind that as a mitigation approach

41:35

at this point? Or is that just a kind of

41:37

fallacy and bargain that we don't

41:40

really want to think about? Well, the

41:43

US Office of Science and Technology

41:45

Policy recently released

41:48

a report recommending

41:50

that the US government invest

41:53

in

41:54

understanding whether or not

41:56

this kind of solar geoengineering is

41:58

worth considering.

41:59

I'd say we're at the very early stages.

42:02

But at the stage where there

42:04

have been the order of 2000 scientific

42:07

papers published on how

42:09

it would work, what the risks might

42:11

be,

42:12

what the social and political

42:15

dynamics might be associated with

42:17

it. So there are tons of things we don't

42:19

understand, but it's increasingly

42:22

coming into focus as

42:24

what you might think of as an emergency

42:28

action for dealing with overshoot. So

42:32

what do you perceive to be the most important

42:35

challenges in our

42:38

transition into a

42:40

truly sustainable, low-carbon

42:43

economy? What are the

42:45

major impediments at this point?

42:47

I think the biggest challenge

42:50

we face is the challenge of

42:53

building a durable political coalition

42:55

around

42:56

action on climate.

42:58

The

42:59

Inflation Reduction Act and

43:01

the bipartisan infrastructure law

43:03

and the

43:04

CHIPS Act from the Biden administration of all

43:07

put large amounts of money out there and

43:09

we're beginning to see real progress

43:11

as a result of deploying those funds.

43:14

But we still live in a world where the

43:16

results of the next presidential election

43:19

could

43:20

knock a whole bunch of those policies

43:23

and knock a bunch of that funding

43:25

out of the arena.

43:26

And I think for entities that

43:29

need to make long-term plans, utilities,

43:33

auto manufacturers, energy

43:36

producers, it's really important

43:38

to have a

43:39

predictable landscape for

43:42

long-term investments.

43:44

And I think that without a

43:46

durable political coalition

43:48

around action,

43:50

we'll continue to operate much more

43:53

slowly than we should. And I think

43:55

there are some key features

43:57

of this durable political coalition

43:59

that we need.

43:59

We haven't yet tackled

44:01

with the seriousness that we need

44:03

to.

44:04

One is what happens to the

44:07

individuals and the communities

44:09

that

44:10

are negatively impacted

44:13

by action on climate. What happens to coal mining

44:15

communities? What happens to oil

44:17

and gas producing states?

44:19

What happens to the nations that depend

44:22

on

44:22

exporting fossil fuels for their

44:25

economic viability? And

44:28

those questions need to be answered

44:30

in a much more serious way than they have

44:32

been now.

44:34

I think there are serious questions about

44:37

the inequalities

44:39

and injustices that are introduced

44:42

by action on climate that

44:45

need to be dealt with. And there

44:47

are serious questions about how

44:50

we're going to think about

44:52

balancing

44:54

diverse interests

44:56

that are aligned on

44:58

many things, but not perfectly aligned.

45:01

And one of the cases where we see

45:03

the kind of challenge that I think is going to be

45:06

really important for the future and really needs

45:08

to be solved

45:10

is all of the controversy over the siting

45:12

of offshore wind power installations.

45:16

Everybody's in favor of offshore wind except

45:19

where they see the windmills or

45:21

in favor of

45:23

a sea-scale solar, except

45:25

where it has the potential to

45:28

alter the migration of a desert tortoise

45:31

or impact an endangered

45:33

species. And those

45:36

concerns are really important. They can't

45:38

be dismissed out of hand.

45:41

But we need to figure out some way to make

45:43

progress around these barriers

45:45

that are, in

45:46

most cases, purely in

45:49

the human dimension.

45:50

It's not that we lack the technology

45:53

or that we

45:55

don't have the engineering capability

45:58

to

45:58

deploy a solution. it's that we

46:00

haven't got the political

46:03

and financial landscape laid

46:05

out in a way that lets us make progress. Well,

46:08

it seems to me that a lot of the politics is

46:11

driven by this claim,

46:14

either implicit or explicit,

46:16

that

46:17

the consequences of really transitioning

46:20

to a low-carbon economy would be

46:23

economically ruinous, right? It's

46:25

just way too expensive.

46:27

Our economy requires

46:29

continuous growth. I mean, it's

46:31

really, you know, all of our systems and institutions

46:33

assume continuous growth.

46:36

It's really almost a Ponzi scheme.

46:39

And the renewables

46:41

really aren't up to the task of

46:44

providing all the energy we need. There's

46:47

this piece about nuclear that I'd love you to address

46:49

because, you know, it seems like nuclear

46:53

needs to be part of this conversation

46:55

and we're really, you know, we really haven't done

46:57

what we've needed to do to build new

47:00

generations of nuclear plants. So

47:03

there's this sense that it's just too, it'll

47:05

be too costly to

47:06

take this message,

47:09

this imperative really, to

47:11

decarbonize seriously, you

47:14

know, especially in the developed

47:16

world, even in places like the United States and Europe.

47:19

And then when you look at other

47:21

countries in the developing world

47:24

or between the developing world and

47:26

the most developed places, you know, places like

47:28

India,

47:29

it seems a species

47:31

of first world cynicism to

47:33

say that they need to be

47:36

thinking about their carbon footprint

47:38

when they simply are following

47:40

the industrial path that

47:43

we in the developed world followed toward

47:45

prosperity, right? So we're demanding of them

47:48

things that we didn't do ourselves. And

47:51

then there's the question of, you know, how to

47:53

actually make that demand and incentivize

47:55

them appropriately, ethically,

47:57

and politically.

47:59

How do you

48:02

respond to that arguably disjointed

48:04

set of concerns about just the cost

48:07

of all of this, both in the developed

48:09

world and in the developing world?

48:11

A few years ago,

48:13

it was really unclear how we

48:15

would ever bring emissions

48:17

of carbon dioxide, especially,

48:20

down to zero.

48:22

But now, there are

48:25

really clear pathways that

48:27

combine being equitable,

48:30

affordable, reliable,

48:33

and safe.

48:35

And I hope it's well known

48:38

that

48:39

electricity from photovoltaics is

48:41

now in almost every part of the world

48:43

cheaper than electricity from fossil.

48:47

We've learned

48:49

a huge amount about

48:51

how to integrate large

48:53

amounts of renewable electricity

48:55

into the grid and are making really

48:58

impressive progress in

49:00

figuring out how to combine

49:03

renewable sources

49:05

into a truly reliable

49:07

system.

49:08

But there are big problems

49:10

with, it's

49:11

called intermittency, with

49:14

what do you do when the wind's not blowing or

49:16

the sun's not shining?

49:18

And if we were going to deploy

49:20

expensive lithium ion batteries

49:23

to be the source

49:25

of electricity

49:26

when the sun's not shining, it

49:28

would be terribly expensive.

49:30

But there are a whole bunch of strategies we

49:33

can use

49:34

to provide the kind of reliability

49:37

in the electrical system

49:39

and in transportation and in manufacturing

49:42

that

49:43

we need. One set

49:45

of options does involve power

49:47

from sources like nuclear. Nuclear is non-emitting,

49:50

and

49:52

we have many countries that are

49:55

reliant on nuclear and have been

49:57

for decades. They're

49:58

obviously...

50:00

profoundly important questions

50:02

about the

50:03

safety of nuclear, about their

50:05

connection

50:07

with weapons proliferation, and about

50:09

the

50:10

susceptibility to terrorism.

50:12

But there's also a lot of progress being made

50:15

in nuclear. And my

50:17

personal feeling is that

50:19

it's important to encourage that progress,

50:22

even if it turns out that

50:24

nuclear can't compete on price. And

50:27

at this point, the impression I

50:29

have is that nuclear will have real

50:31

trouble being competitive in

50:34

most parts of the world,

50:35

because renewables are so cheap.

50:38

One of the challenges with nuclear is that

50:41

every increment of extra nuclear

50:43

power you add to the grid is an

50:46

investment of hundreds of millions

50:48

of dollars. And it's hard to experiment

50:50

and try different things when each increment

50:53

is so expensive. The nice thing about

50:56

photovoltaics and windmills is that

50:58

they can scale in tiny little

51:01

increments.

51:02

Another feature of the future

51:04

energy system that I

51:06

think we need to think really seriously about

51:08

is continuing to use

51:10

fossil fuel resources,

51:13

but connect them with carbon capture and storage.

51:16

We know how to

51:17

capture carbon dioxide and

51:20

compress it and pump it into underground

51:22

formations.

51:23

That's one of the main techniques we

51:26

use for extracting oil and gas

51:28

now. And

51:31

we know how to run a

51:33

power plant with CO2 capture.

51:36

We know how to run a biofuels plant with

51:38

CO2 capture,

51:40

and especially at the margins where

51:42

we're trying to figure out how to provide

51:44

that last increment of reliability,

51:47

how we're trying to fill in the gaps

51:49

where

51:50

the renewables aren't working,

51:53

we have lots of potential

51:56

for countries that already have a lot of deployed

51:58

infrastructure.

51:59

fossil with CCS.

52:01

And then an area that I

52:04

think is incredibly exciting and

52:06

really has the potential

52:08

to

52:09

map out the bridge from where

52:11

we are now to a system

52:13

that's fully based on non-meaning

52:17

technologies

52:18

involves hydrogen.

52:19

Currently, we make hydrogen from natural

52:22

gas

52:23

and the way you make hydrogen

52:25

from gases, the carbon

52:28

part of the natural gas goes into the

52:30

atmosphere is CO2 when the hydrogen gets

52:32

used.

52:33

We could capture that carbon and

52:35

pump it into underground reservoirs, that's

52:37

often called blue hydrogen. And

52:40

then we can use the hydrogen to make electricity

52:42

either by burning it or by running

52:45

it through a fuel cell. But

52:47

we also know a lot about how to

52:49

make hydrogen from electricity

52:52

by splitting water that's currently

52:54

quite a lot more expensive than making it

52:57

from natural gas, but we're seeing progress

52:59

there.

52:59

And once we have large

53:02

amounts of hydrogen available,

53:04

we can use that hydrogen as

53:07

the equivalent of a gigantic

53:10

unlimited battery

53:12

and use the hydrogen to make electricity

53:14

when the sun's not shining, use the

53:16

sunshine to make hydrogen when the

53:19

sun is shining. And

53:21

the

53:22

pathway that looks to me the most

53:24

attractive for this transition

53:27

to a truly

53:28

non-emitting energy system

53:31

is to take advantage of our

53:33

ability to make blue hydrogen

53:36

now, hydrogen from natural gas, capturing

53:38

the CO2 so it's a non-emitting.

53:41

And then as the

53:43

cost of making hydrogen

53:45

from sunshine,

53:46

from electricity goes down,

53:49

we can transition over to that. It's going to take

53:51

decades,

53:52

but that's a pathway that

53:54

looks at this point

53:56

like it'll be cheaper than continuing

53:58

to get energy from fossil fuel.

53:59

You look across the

54:02

transportation and manufacturing and electricity

54:05

spectrum there. There are lots of details that

54:07

need to be worked out and there are some new technologies

54:10

that are needed, but the new technologies

54:14

aren't the limiting factor

54:16

at this point.

54:17

We have access to a lot of

54:20

amazing technology now

54:22

that can get us a long way to

54:24

the solutions.

54:26

I'd like to say a couple things about

54:28

your comment about

54:30

what should be the timing for the engagement

54:32

of countries that are

54:35

not the richest, including countries

54:37

that are the poorest. There

54:40

is a strong motivation

54:43

that the

54:44

wealthy countries should be

54:46

leading the transition.

54:48

They're the ones that are

54:50

responsible for the historical emissions.

54:52

They're the ones that have the

54:55

economic resources to make the

54:57

transition,

54:58

and they also are the ones that have the finances

55:00

to

55:01

make it affordable. And

55:04

as the non-emitting energy sources

55:06

become the cheapest sources

55:09

and the most reliable ones, they'll be increasingly

55:11

attractive in

55:13

the developing world.

55:15

With the middle-income countries like

55:17

India and China that

55:20

clearly want to be leaders in

55:22

climate-responsive space,

55:25

there are lots of opportunities for them to

55:27

invest in new technologies now,

55:30

but they also will be slower

55:32

than the richest countries simply as

55:35

a result of the fact that

55:36

they don't have the full

55:39

kind of capabilities that we have. And we're

55:41

going to need to think really hard about how

55:43

the rich world interacts

55:45

with the poor world in terms of

55:48

driving the energy transition.

55:52

There are kind of two models you can think about.

55:54

One is that

55:55

in the rich world, we make

55:57

the non-emitting options so cheap.

56:00

that they're the obvious choice. And

56:02

the other option is that

56:05

we really rethink what

56:07

international assistance means and whether

56:10

financial assistance for

56:12

accelerating the transition

56:14

in poorer countries is in

56:16

the interests of the rich world because

56:19

it decreases things like risks

56:21

of political instability.

56:23

And we may see some of that. And

56:25

I suspect that if we see it, it will be

56:27

in subtle mechanisms like

56:30

changes in the way

56:32

that the World Bank or the International

56:34

Monetary Fund think about their

56:36

loan portfolios.

56:38

But one of the things we need

56:40

to make sure of, and this

56:42

is again in the spirit

56:44

of building durable political coalitions,

56:47

is that this isn't going to work if

56:49

the

56:50

rich world turns to the poor world and

56:52

says, you folks have

56:54

to impoverish yourself

56:56

further by investing

56:59

resources that you don't have in

57:01

an accelerated transition. I

57:04

think there are likely to be decades

57:08

when the rich

57:10

world has made tremendous progress,

57:13

may even have

57:14

greenhouse gas emissions down to zero

57:16

when countries in the poor world will still

57:19

tend to

57:20

need to rely on fossil fuels for transportation

57:24

and electricity generation and manufacturing.

57:27

And we need to build that into

57:29

the way we

57:30

think about what the timing

57:32

of reaching net zero should be. One of the

57:35

things that

57:36

I'm always frustrated at is that

57:38

when we talk about the Paris compliant

57:41

time goal being zero emissions

57:43

by 2050, even

57:46

the richest

57:47

countries, the richest institutions tend

57:50

to say, okay, well, I

57:52

can make a plan to

57:54

reach net zero by 2050

57:56

when if everybody

57:58

needs to... to reach

58:01

zero emissions by 2050, the

58:04

richest actors need to be way

58:07

ahead of that. And I think

58:09

we still haven't stepped up to

58:11

addressing that aspect of the equity

58:13

challenge.

58:14

What role does a carbon tax play

58:17

in this picture? There are

58:19

lots of ways you could think about

58:21

incentivizing decreases

58:24

in emissions.

58:25

Economists tend to love

58:27

carbon tax because it

58:29

really lets the market sort

58:32

out which approaches are going to be most

58:34

effective and which aren't

58:37

going to be wastes of money.

58:39

And at

58:40

least in principle, a carbon

58:42

tax could be deployed in

58:44

a strategic way that would be globally

58:47

fair that could really

58:49

encourage the rapid deployment

58:51

of the best possible technologies.

58:54

There are other things we

58:56

can do. If you look at the

58:57

history of environmental regulations,

59:00

we've actually made more progress with command

59:02

and control approaches than we have

59:05

with

59:06

market-based approaches.

59:08

So with the Clean

59:10

Water Act,

59:11

most of the requirements have simply said,

59:14

you can't put this pollution in the water or

59:16

you can't pollute at a higher level than this.

59:19

There's nothing

59:21

particular to say that

59:24

a carbon tax would work better than a command

59:27

and control approach. It

59:29

really depends on what

59:31

the politically enabling conditions

59:34

are. There's

59:35

been a lot of discussion recently about

59:37

what's called a border adjustment,

59:40

where a

59:41

country with a carbon tax would

59:43

say, okay, well,

59:44

any product that is imported

59:47

from a country that doesn't have a carbon tax

59:50

has to pay a carbon tax at

59:52

the border to the country that the product's

59:54

coming into. And of course,

59:56

that is a big boost

59:59

for...

1:00:00

local manufacturing,

1:00:02

as well as for addressing

1:00:05

the emissions associated with

1:00:07

different products.

1:00:08

And maybe the concept of

1:00:10

a carbon tax with a border adjustment

1:00:13

will make it more politically palatable.

1:00:15

My sense

1:00:18

is that in the US, we're

1:00:20

not very close to agreement

1:00:23

on the value of a carbon tax, even though

1:00:25

it could, for example, be used to

1:00:28

produce a dramatic decrease in income

1:00:30

taxes.

1:00:31

And I think what's really important is

1:00:33

that we come up with something

1:00:36

that people can agree on politically

1:00:39

and move forward with that and not

1:00:41

let the perfect

1:00:43

be the enemy of the good, even

1:00:45

though carbon tax might be

1:00:48

something like the perfect. Finally,

1:00:51

what are you expecting here?

1:00:53

If you had to guess what path

1:00:56

we're going to take through this,

1:00:58

the range of possible outcomes in terms

1:01:00

of

1:01:01

mitigating, failing to mitigate, creating

1:01:04

political consensus necessary to mitigate,

1:01:07

failing to do that. If you had to guess

1:01:10

about what the world is going to look like in 20

1:01:12

years, 30

1:01:13

years,

1:01:15

what are you expecting?

1:01:16

Is there a degree of optimism

1:01:18

or pessimism that's underwriting

1:01:20

your current efforts, or are

1:01:23

you just

1:01:24

agnostic and doing what you feel

1:01:26

we need to do in any case?

1:01:29

Well, I want to make it clear at the outset

1:01:31

that I don't have any special

1:01:34

insight into what kind of decision

1:01:36

countries around the world are going to

1:01:38

make. I am optimistic

1:01:42

that

1:01:42

the progress that I've seen

1:01:45

in the

1:01:46

past decade has

1:01:48

been really consequential on what

1:01:50

emissions levels are in

1:01:52

most of the rich

1:01:55

countries. Emissions have been decreasing

1:01:58

on a year-by-year basis.

1:01:59

increased in the US last year, but that was

1:02:02

mainly a consequence of the decrease

1:02:04

in the COVID pandemic activities.

1:02:07

But in most countries, emissions are decreasing.

1:02:09

And we now live in a world where

1:02:11

electricity from renewables is

1:02:14

cheaper than electricity from fossil.

1:02:16

We live in a world where

1:02:18

the most attractive transportation

1:02:21

options for private vehicles are

1:02:23

electric and where

1:02:26

heat pumps can improve

1:02:29

the air quality in homes and

1:02:31

where we know that

1:02:32

pollution from gas stoves is

1:02:35

harming people. So lots

1:02:38

and lots of indications that

1:02:40

the technology is ripe

1:02:43

for an accelerated

1:02:45

transition. But

1:02:46

there's still lots of pushback from vested

1:02:48

interests, from

1:02:50

oil and gas companies, from

1:02:52

fossil producing regions of the world,

1:02:55

and lots of

1:02:57

need to work on the

1:02:59

kind of

1:03:00

political coalition that I've been talking

1:03:02

about. I expect us

1:03:05

to not achieve the very best

1:03:07

outcomes,

1:03:08

but to make the transition

1:03:11

in a way and

1:03:13

at a pace that's going

1:03:15

to preserve a livable world. At

1:03:18

least that's my hope. And what that

1:03:20

might mean is that

1:03:22

while we don't meet the

1:03:25

Paris Agreement goal of stabilizing

1:03:27

warming at well under 2C above

1:03:29

pre-industrial, we

1:03:31

might end up pretty close

1:03:33

to 2C, maybe a couple

1:03:35

of tenths above it,

1:03:37

and there will be

1:03:39

incalculable damage associated

1:03:42

with not making the goal,

1:03:44

but it's a lot better to be at 2 or 2.2

1:03:47

than 3.5 or 4. You

1:03:53

picture some of those consequences being

1:03:56

necessary just for rhetorical

1:03:59

effect to get us.

1:03:59

politically aligned

1:04:01

enough to take this seriously

1:04:05

over a time horizon that exceeds the

1:04:08

four-year presidential election cycle.

1:04:10

It seems to me that to speak locally

1:04:13

about the United States in particular,

1:04:15

it's so hard for us to make any decision

1:04:18

with a time horizon

1:04:20

beyond four years politically that

1:04:22

it could well take something

1:04:25

so noxious

1:04:27

and durable as a stimulus

1:04:30

for us to say, okay, whatever our political differences,

1:04:33

we have to be responding to this year after

1:04:35

year after year. This

1:04:37

is now a non-negotiable

1:04:39

decrease in our quality of life.

1:04:42

Are you picturing that being part of the process

1:04:45

where it just, you know,

1:04:46

take whatever it is,

1:04:48

wildfires or any other stimulus,

1:04:50

it just becomes so

1:04:53

onerous and obscene to be living

1:04:55

with these consequences year after year that we

1:04:57

just reset our politics around that?

1:04:59

Yeah, I have many colleagues who

1:05:02

talk about the possibility

1:05:04

that

1:05:05

truly catastrophic extreme event,

1:05:08

a

1:05:09

category five hurricane hitting Miami

1:05:11

or the

1:05:12

kind of

1:05:14

mega heat wave that

1:05:16

Kim Stanley Robinson describes in Ministry

1:05:18

for the Future. And it's

1:05:21

possible that one of these

1:05:23

truly catastrophic events

1:05:26

will

1:05:26

galvanize national and world

1:05:29

opinion.

1:05:30

My expectation is it'll probably be

1:05:32

a

1:05:33

little more incremental than that, that

1:05:35

the

1:05:37

non-emitting technologies will continue

1:05:40

to be

1:05:40

cheaper and better and more

1:05:43

attractive in the marketplace,

1:05:45

that an appreciation that

1:05:47

the

1:05:48

climate change needs to be addressed

1:05:50

will get nailed down with

1:05:53

each wildfire and each extreme

1:05:55

precipitation event

1:05:57

and that we'll just gradually

1:05:59

transition.

1:05:59

to a much stronger

1:06:02

focus on

1:06:03

making progress in this than we

1:06:06

have to date.

1:06:08

And I think that a lot

1:06:10

of that is going to be dependent

1:06:13

on

1:06:14

having this be a world in which there are opportunities

1:06:16

for the

1:06:18

kinds of individuals

1:06:20

and actors that are not seeing

1:06:23

opportunities now.

1:06:24

And that's going to be things

1:06:26

like energy producing states,

1:06:29

oil and gas companies,

1:06:31

individuals who currently work

1:06:34

in

1:06:35

manufacturing or energy production.

1:06:37

And I just

1:06:39

want to close with the thought

1:06:42

that until we're really serious about

1:06:45

these interests that are displaced

1:06:48

by progress on climate,

1:06:50

it's going to be really, really hard to come

1:06:52

up with the kind of broad political

1:06:55

coalition that we need. And

1:06:57

we'll go more slowly

1:07:00

as a result of not building out that

1:07:02

coalition. Hmm. Well,

1:07:04

Chris, thank you for the tour of the

1:07:06

possible apocalypse.

1:07:09

I feel much better educated and strangely

1:07:11

more optimistic for having spoken with you. So

1:07:14

thanks for what you're doing and thanks for bringing your

1:07:16

voice here on the podcast.

1:07:18

I enjoyed the conversation. Thanks so much.