0:03

I think a lot of scientists

0:05

have underestimated these tail risks, if you

0:07

will. These sort of what we used

0:10

to think of as worst-case scenarios for

0:12

how bad the impacts of climate change

0:14

could be. But we're now starting

0:16

to reassess and say that maybe some of

0:18

those worst-case scenarios actually aren't quite

0:20

as low probability as we thought they were.

0:23

Summer is notorious for extreme weather, and

0:25

this summer that seems more likely than

0:28

ever. In the next few

0:30

months, heatwaves, droughts, thunderstorms and hurricanes

0:32

will wreak havoc on regions around

0:34

the world. And climate scientists

0:36

say these events are becoming more

0:38

extreme and dangerous because of the

0:40

changing climate. For example, the National

0:42

Oceanic and Atmospheric Administration's outlook for

0:44

the 2024 hurricane season, which

0:48

just started June 1, anticipates an

0:50

exceptionally high number of storms this

0:52

year. So, why are

0:55

extreme weather events worsening? How is

0:57

climate change contributing to this development,

0:59

and what measures are being taken

1:01

to adapt to this new reality?

1:07

This is Columbia Energy Exchange, the

1:09

weekly podcast from the Center on

1:12

Global Energy Policy at Columbia University.

1:15

I'm Bill Loveless. Today

1:22

on the show, Radley Horton. Radley

1:25

is a professor at Columbia

1:27

University's Climate School, where he

1:29

teaches and researches climate extremes,

1:31

risks, impacts and adaptation. Radley

1:34

was a convening lead author for the

1:36

United States' third national climate assessment, and

1:39

he is currently a principal investigator

1:41

for NOAA, focusing on climate risk

1:43

in the urban northeast. I

1:46

talked with Radley about the outlook for

1:48

extreme weather events across the globe, and

1:50

why the intensity and severity of extreme

1:52

weather is expected to increase. We

1:54

discussed the field of climate attribution science,

1:57

and the extent to which adaptation is

1:59

happening. are not happening in the US.

2:02

I hope you enjoy our conversation. Radley

2:05

Horton, welcome back to Columbia Energy Exchange. It's

2:07

great to be back with you, Bill. Yeah,

2:09

looking forward to the conversation again. I recall

2:11

finally one we had, gosh, I guess it

2:13

was a couple of years ago, but some

2:15

of the topic is new, but

2:18

they're, as we know, ever-changing

2:20

events that warrant even more

2:23

discussion. And among them are

2:25

new forecasts, scientific research, telling us

2:27

that a hotter than usual summer

2:30

is likely to occur in the United States and many

2:32

other parts of the world. The

2:35

year 2023, of course, was

2:37

the hottest year of record. What's

2:40

going on, Radley? Yeah,

2:42

I mean, I think a lot of

2:45

climate scientists, frankly, have been surprised by

2:47

just how hot it's been, so

2:49

soon, if you will, right? The

2:51

idea that at this level of greenhouse

2:53

gas concentrations, not the level that

2:56

we're expected to be at in the future,

2:58

but at this level, we can already have

3:00

a year, as we've had over

3:02

the later part of 2023 and

3:04

early part of 2024, that's

3:06

over 1.5 degrees Celsius warmer

3:09

than that baseline climate.

3:11

So one way that

3:13

I've been describing it is, not only has

3:16

this been the warmest year on record, but

3:18

if you were to line up the temperatures

3:20

from, say, the last 50 years, the last

3:23

100 years, the last

3:25

year really stands out in

3:28

that it's so much warmer than any of the prior

3:30

years. If you stack them all, a lot of the

3:32

years would be really close together, but

3:34

for a lot of variables, late 2023 and

3:36

early 2024, it's

3:39

not just higher, it's a lot higher than

3:41

any of those other temperatures were. And

3:44

then in terms of the explanations for it, we

3:46

do have to acknowledge that we've been in an El

3:49

Nino event for a lot of this time. We're

3:51

coming out of it, and we can talk

3:53

about that, but El Nino does tend to

3:55

warm the planet. That's part of the story,

3:57

but it's certainly not the whole story, right?

3:59

We've had... these warming El Nino

4:01

events before, never did we see

4:03

temperatures so far above

4:05

the long-term averages. You

4:07

know, I think it's you mentioned, you know,

4:10

La Nina, El Nino, help

4:13

for those of us who may not

4:15

entirely understand what they are, explain to

4:17

us and make sure that we're understanding

4:19

what is happening in terms of those

4:22

atmospheric conditions. Absolutely. So the

4:24

first word that comes to mind

4:26

with El Nino and La Nina

4:28

is climate variability. It's the idea

4:30

that there is some sort of

4:32

natural range, some oscillation that goes

4:34

on within the climate system. And

4:36

specifically when we talk about El

4:38

Nino and its counterpart

4:40

La Nina, it's an oscillation or

4:42

interaction between the upper ocean

4:46

and the atmosphere above it, especially

4:48

centered over the Pacific Ocean. And

4:50

basically when we have an El Nino

4:52

event, which happens roughly every five to

4:54

seven years or so, you

4:56

get uncharacteristically warm water in the

4:59

eastern part of the tropical Pacific.

5:01

So off the coast of Peru,

5:04

Ecuador, those are areas that actually tend to

5:06

have pretty cool water for the tropics. But

5:09

during an El Nino event, the waters there

5:11

get really warm and simultaneously

5:14

having that warm water there

5:16

changes the atmospheric circulation, the

5:18

pattern of winds, the patterns

5:20

of clouds and rain in

5:22

ways that reinforce those ocean

5:24

temperatures. So it's really, it's

5:26

a positive feedback cycle, if

5:28

you will, between the atmosphere

5:30

and the ocean starts out

5:32

centered in the tropical Pacific

5:34

usually, but ends up through

5:36

something called teleconnections, having impacts

5:38

all around the world that

5:40

are varied, but tend to

5:42

include higher average temperatures for

5:44

the whole globe during an El Nino

5:47

event when the East Pacific Ocean is

5:49

warm. And you have

5:51

atmospheric wind patterns that support that. And

5:54

speaking again of these atmospheric conditions

5:56

and these warm waters in the

5:58

off the coast. in the Atlantic,

6:00

for example, there's

6:03

more worrisome news. The new

6:05

2024 hurricane report from the

6:07

National Oceanic and Atmospheric

6:09

Agency has just come out. It

6:12

suggests an exceptionally high number of

6:14

storms for the hurricane season that

6:16

began June 1st. Another

6:18

sign of climate change? Well,

6:21

you know, I think in

6:23

some sense, yes, mostly a lot

6:25

of factors any year can go into a

6:28

forecast like that. But you're right, when we

6:30

look at this year, we

6:32

haven't just had exceptional atmospheric

6:34

temperatures. The oceans across much

6:37

of the world, including, as

6:39

you noted, the Atlantic, have

6:42

been exceptionally warm. All

6:44

things being equal, that gives more fuel

6:46

for tropical storms, for hurricanes, because you

6:49

really need a warm ocean in order

6:51

for those storms to be able to

6:53

form. So a lot of things go

6:56

into a forecast like this forecast from

6:58

NOAA. And just to delve in

7:00

a little more deeply into that, they said

7:02

that there's, by their estimation, an

7:06

85% chance of an

7:08

above-normal hurricane season, only

7:11

a 5% chance of a below-normal season.

7:14

If all things were equal, it'd

7:16

be like a third probability of

7:18

above-normal, third probability of below-normal. So

7:20

this is a very different forecast.

7:22

They are really betting

7:25

on a lot of strong storms. A

7:29

lot of that is, as we

7:31

just said, this incredible warmth in the oceans,

7:33

and especially the Atlantic. But El Nino is

7:35

part of that story too, and especially the

7:38

fact that we're pivoting now towards

7:40

a La Nina, to sort of the opposite

7:42

of the El Nino conditions, where we have

7:45

a little cooler conditions than normal in the

7:47

East Pacific specifically, and some changes

7:49

in atmospheric patterns. When we tend to have

7:51

a La Nina event, that

7:54

actually encourages a strong Atlantic hurricane

7:56

season. And there's a few reasons

7:58

for that, but... to sort of

8:00

oversimplify it, we could say that it's related

8:03

to wind shear. Maybe wind shear doesn't sound

8:05

that simple, but it's basically the idea that

8:08

as you look across a vertical profile,

8:10

if you will, if you look up

8:12

in the atmosphere, if you

8:14

have a different wind direction or wind

8:17

strength near the surface, like near the

8:19

ocean, if you will, then

8:21

you have up high in the

8:23

atmosphere. If there's very different wind

8:25

directions, that creates shear, and

8:27

it basically kind of tears apart hurricanes

8:30

because hurricanes want to try to form

8:32

a consistent kind of vertical structure

8:34

from the surface up to high

8:36

in the atmosphere. So during La

8:38

Nina events, you tend to have

8:40

a little less of that wind

8:43

shear, which makes it easier for

8:45

hurricanes to form and strengthen.

8:47

So you combine that with the warmer

8:49

ocean temperatures in the Atlantic, which are

8:51

partly due to global warming, and you

8:53

have the recipe for this really

8:55

strong forecast. Yeah, I

8:57

was reading a comment by an

9:00

atmospheric professor and scientist

9:02

at the University of Miami, Benjamin

9:04

Cortman, who described the

9:06

Atlantic Ocean conditions as, quote,

9:09

unprecedented, alarming, and in

9:11

out of bounds anomaly. That's

9:13

absolutely right. I'm glad to hear him

9:16

saying that. I think we need more

9:18

climate scientists coming out and really acknowledging

9:20

that these are surprises. They're outside the

9:22

bounds of what a lot of us

9:24

thought were possible in terms of the climate system. And

9:28

as you start to push further, too,

9:30

into some of the societal impacts, if

9:32

we want to talk about the fire

9:34

season, for example, that we observed across

9:36

Canada last year by some measures four

9:38

times more area burning than ever has

9:40

before on record. If we look

9:42

at some of the impacts on human

9:44

health, on agriculture, there, too,

9:47

I think a lot of scientists have

9:49

underestimated these tail risks, if you will.

9:52

These sort of what we used to

9:54

think of as worst case scenarios for

9:56

how bad the impacts of climate change

9:58

could be, but we're now, starting to

10:00

reassess and say that maybe some of those

10:02

worst case scenarios actually aren't

10:04

quite as low probability as we thought they

10:06

were. Yeah, you mentioned Canada, of

10:08

course, where these, the

10:11

drought and heat have started, the wild

10:13

season, wildfire season earlier than usual this

10:15

year. And of course, you know, you

10:18

look around the world, Mexico, which has

10:20

had been in the grip of a

10:22

so-called heat dome that has locked hot

10:25

and dry weather in place and look

10:28

over to Asia, Thailand, China,

10:30

Japan, Vietnam, the Philippines, Pakistan,

10:33

have all been on the throes of intense heat for

10:36

at least a month. You

10:39

said, Radley, that you think there

10:41

may be some underestimation that's occurring.

10:45

Why is that? Is that things are happening

10:47

so quickly now that it's

10:50

proven difficult to catch up

10:52

and to appreciate what has taken place

10:54

in the most recent past? Yeah, I

10:56

think in some ways, that's sort of

10:58

the question of the age, trying to

11:00

unpack all the dimensions of

11:02

what you just asked. I'll actually start with

11:04

something a little more basic, though, just to

11:06

reinforce the point that you are making about

11:09

how exceptional the recent heat has been. I

11:11

saw one statistic that, again, the first five

11:13

days of May alone of 2024, 70 countries

11:15

had set all-time

11:20

records for high temperatures for that particular

11:22

date, whether it was May 2nd or

11:25

May 4th or whatever. That

11:27

sort of gives you a sense of

11:29

how widespread, as you're saying, these exceptional

11:31

temperatures have been. But

11:33

now you're sort of pivoting to the heart of

11:36

your super important question. I mean,

11:38

there's so much to unpack here. There

11:41

certainly has been a real dialogue around

11:44

are we seeing things happening faster than we

11:46

thought. Overall, my perspective

11:48

is yes, but as a scientist,

11:50

we have to unpack it very

11:52

carefully. So in some

11:55

ways, I think the first

11:57

question is our greenhouse gas

11:59

concentrations and and emissions occurring

12:02

at higher rates than

12:04

anticipated. And on that

12:06

one, my perspective is probably, no, not

12:08

really. I think if anything, I mean,

12:11

clearly we need to reduce our emissions

12:13

dramatically, but just sort of the basic

12:15

question of, are we seeing higher

12:18

emissions, higher greenhouse gas

12:20

concentrations, then say

12:22

10 years ago, we thought, you know, might

12:24

be the case. Not really.

12:27

Actually, you know, emissions, while far

12:29

too high by any measure, aren't

12:32

necessarily higher than scientists and other

12:34

experts, energy experts, thought they would

12:36

be. The problems come

12:39

after that, I think, if we're asking this

12:42

question of, are we seeing surprises? So

12:44

the next question to me is

12:46

about the sensitivity of the climate

12:49

to greenhouse gas concentrations of a

12:51

certain level. And here's sort

12:53

of the first big source of concern for

12:55

me, because I do think, as we alluded

12:57

to earlier, that maybe, just maybe,

13:00

we're starting to see signs that as

13:02

the planet warms, due

13:04

to greenhouse gases, some feedbacks could

13:06

be kicking in that lead to

13:09

more warming at a faster rate

13:11

than the climate model suggested. So it's not

13:13

that the greenhouse gas concentrations are higher than

13:15

we thought. It's what if we're gonna get

13:17

more warming for a given

13:19

amount of greenhouse gas concentrations than we

13:21

thought we would? And not

13:24

just global average warming, but what if

13:26

we're gonna see more heavy rain events

13:28

at a greenhouse gas concentration than

13:30

we thought we would? More extreme

13:33

heat events across the world, more

13:35

unprecedented heat extremes. You pick the

13:37

place, right? The Pacific Northwest heat

13:39

wave of 2021, sadly,

13:41

there's just too many examples. So

13:43

I think this is a

13:46

very active area of debate. There are scientists

13:48

who wouldn't go out this far on a

13:50

limb, but I certainly think, as Ben

13:53

Kurtman said, there's more and

13:55

more evidence that our models could

13:57

be missing some climate. changes

14:00

for this greenhouse gas concentration. And

14:02

then from there, the final piece

14:04

would be the impacts of

14:07

those higher temperatures, of those heavy

14:09

rain events, of those heat waves

14:12

on society. Have we underestimated the

14:16

human health effects? Have we

14:18

overestimated how quickly crops could

14:20

dry out? Forests could start to

14:22

burn. Just a few of

14:24

many examples of how in these interconnected

14:26

systems, there too, we may have failed

14:29

to appreciate how vulnerable we are as

14:31

we nudged the climate higher. And

14:34

you reminded me in an exchange we had

14:36

before we went on live

14:39

here on the air, so to speak, that

14:42

when you consider this, you

14:44

have to realize it's not just the

14:46

heat. We're talking about these high temperatures,

14:48

right? But it's the humidity

14:50

as well. The combination

14:52

of those two have impacts, often

14:54

deadly. That's right. And

14:57

for really, for humans, for other large

14:59

mammals, they don't just experience the air

15:01

temperature. It's so critical to know how

15:03

much moisture is in the air as

15:06

well. That's what determines

15:08

how effectively we are able to sweat,

15:10

for example, because if conditions

15:14

are pretty dry, desert conditions, if

15:17

you're in the shade, if you have an

15:19

endless supply of water, if

15:21

you're not exercising or overexerting yourself,

15:24

a healthy human, right? You're healthy.

15:27

Some people have preexisting health conditions. They're elderly

15:29

or very young. But if you're healthy, you

15:32

can sustain pretty high air

15:34

temperatures, again, if the humidity is low.

15:37

The dangers really start to kick

15:39

in if you have high temperatures

15:41

combined with something

15:43

approaching full 100%

15:45

relative humidity. These are

15:48

the situations where sweating is not as

15:50

effective. It doesn't cool you enough. And

15:53

you see people overexerting

15:56

themselves really quickly. And the effects,

15:58

of course, extend. to our

16:00

energy grid, right? The biggest

16:03

strain on energy systems, the biggest

16:05

need for air conditioning is

16:07

when you have those really humid episodes

16:09

that are occurring as well. Yeah,

16:13

I wanna get into the impacts

16:15

on things like the grid, but

16:17

in that conversation of heat and

16:19

humidity, I think it's

16:22

important to discuss something that you explained very

16:24

well to me in the past when we've

16:26

had conversations, and that is the so-called wet

16:28

bulb temperature, right? That is the

16:30

indicator that helps us understand at what point

16:32

there's danger for people under

16:35

stressful heat. Right, so the best way

16:38

to think about the wet bulb temperature

16:40

is actually, unlike a lot of what

16:42

we talk about in climate science, it's

16:44

an actual physical thing that you can

16:47

visualize. So the wet bulb temperature basically

16:49

means think of a regular thermometer

16:51

like you're used to. It's

16:53

got a little bulb on the bottom of it. So

16:56

normally you would just

16:59

record the regular temperature, which

17:02

is the air temperature on that thermometer. What

17:04

differentiates wet bulb temperature is if

17:07

you imagine that same thermometer, but

17:09

now imagine that the bottom of

17:11

it, that circular bulb had a

17:14

wet cloth of some kind right

17:18

around it that stayed permanently wet

17:21

somehow. Basically, if

17:23

you're in a dry desert environment,

17:25

you're gonna have a lot of

17:27

evaporation of the water that's sitting

17:29

on that cloth into the atmosphere,

17:32

which is a cooling process that

17:35

would drop the temperature in that

17:37

thermometer. But if it's

17:39

a very humid environment, you

17:41

won't have much evaporation from that

17:43

cloth into the air, so

17:45

the temperature won't drop very much. The

17:48

wet bulb temperature is

17:50

basically how cool that thermometer can

17:52

get through perfect evaporation. So now

17:54

we can step away from the

17:56

thermometer and talk about a person,

17:58

right, trying to sweat to

18:01

cool themselves. If there's a

18:03

lot of moisture in the atmosphere and

18:05

temperatures are very high, sweating

18:07

becomes a very inefficient process. The

18:10

wet bulb temperature is high because there's

18:13

not a lot of effective evaporation or

18:15

sweating happening off of a person. Yeah,

18:18

so you could be, the wet bulb

18:20

temperature may be, say, what, 95

18:22

degrees Fahrenheit? Yeah, I mean,

18:24

that's like, you know, incredibly

18:26

dangerous, a wet bulb temperature of 95. And

18:29

that's confusing messaging, right? Because when we just think

18:31

of air temperature, 95 degrees is very bad, but

18:36

depending where you are, if you're in

18:38

a dry place, you know, maybe manageable,

18:40

maybe not even that surprising. A wet

18:42

bulb temperature of 95 Fahrenheit is

18:45

something that circling back to that sort

18:47

of mythical person who's in perfect

18:49

health, in the shade, endless

18:51

supply of water, still, if

18:55

the wet bulb temperature was that

18:57

high, could overheat, could start to

18:59

die, essentially, in a time period

19:01

of something like six hours. It's

19:03

thermodynamically impossible not to overheat, not

19:06

to get heat exhaustion and then heat stroke, because

19:08

your organs, you know, we generate a lot of

19:10

heat within our bodies to begin with. You can't

19:12

shed that heat. You start to

19:14

have these really scary things like, you know,

19:17

organ failure. Fortunately, 95 degree

19:20

wet bulb temperatures are exceedingly rare. We

19:22

think that's only been experienced in a

19:24

couple places, maybe Pakistan,

19:26

parts of the Persian Gulf, for

19:29

just a few hours at a time. But

19:31

what's unfortunate is

19:33

that it's not uncommon to experience wet

19:35

bulb temperatures of, say, 86,

19:38

88 degrees Fahrenheit. And

19:41

those are plenty high enough to

19:44

mean that, say, an outdoor laborer,

19:46

you know, someone with a

19:48

preexisting health condition, could easily

19:50

overheat. And it's

19:52

important to remember that wet bulb temperature typically

19:55

is going to be lower than the reading

19:57

you're getting when you look at the thermometer.

20:00

so to speak, right? Yeah, but still super

20:02

dangerous, right. You talk also,

20:04

Radley, of something called

20:06

compound extreme events. A

20:09

lot of times we're talking of a

20:11

particular impact from hot weather, but sometimes

20:13

there's more things going on that we

20:15

may not even realize that makes a

20:17

situation even worse in terms of the

20:19

threats that come from heat, humidity, or

20:21

a combination of the two. Yeah,

20:24

absolutely. This to me has been one of the

20:26

sort of emerging areas in climate

20:28

science and risk assessment more

20:31

generally. And basically

20:33

it's not too much of an

20:35

exaggeration to say that 10 or

20:37

15 years ago, when a leading

20:39

city thinking about adaptation to extremes,

20:42

or a company thinking about adaptation

20:44

to extremes, insurers, reinsurers, just

20:46

thought about one climate variable in one

20:48

location at a time. A city might

20:50

say, how bad could our worst heat

20:52

wave be? How bad could our

20:54

worst rain event be? You

20:57

didn't have this thinking that were of this

20:59

sort of compound extremes thinking that's emerged

21:01

about how these events can

21:03

be interconnected and how they can be

21:06

correlated. So enter the sort

21:08

of thinking around compound extremes and

21:10

suddenly it's, well, what if multiple

21:12

areas around the world experienced an

21:14

extreme event at the same time,

21:16

right? So what if it's not

21:18

just a heat wave in one

21:20

place, but what if

21:22

multiple agricultural regions, bread

21:25

baskets, if you will, are experiencing

21:27

heat and maybe heat and

21:29

drought at the same time? Now

21:31

the impacts can be much more severe. You

21:33

start to have to think about something that

21:35

maybe society could endure in one region, but

21:39

if multiple regions simultaneously experience reduced

21:41

crops, you can have a nonlinear effect

21:43

where the price of basic commodities doesn't

21:45

go up a little, it goes

21:47

up a lot due to shortages. And

21:50

the most vulnerable populations literally don't have

21:52

enough to eat anymore. So

21:55

that's the sort of nonlinear impacts

21:57

of simultaneous extremes in multiple

21:59

places. Another critical

22:01

example is sequences of extremes

22:04

in any one place, right? Sort of

22:06

circling back to the power grid, which

22:08

we talked about briefly, a

22:11

city really just, you shouldn't just say, what's

22:13

the worst storm we could get that

22:15

could knock out power? Or what's the worst

22:17

heat wave we could get when we really

22:19

need that power for, you know, to cool

22:22

our vulnerable people and keep our economy going?

22:24

They ought to ask, what

22:26

is the risk before climate change,

22:28

the probability and after climate change

22:30

of a sequence of

22:33

having, say, the storm that knocks

22:35

the power out through high winds,

22:37

through flooding, and then

22:39

having the heat wave right after it, right? Or

22:41

before you have time to recover. So that's sort

22:43

of the nature of thinking

22:45

about compound extremes. One

22:47

last piece of it could be, it

22:50

might just be one location, one moment in

22:52

time, but it's multiple variables, right?

22:54

It's a hurricane that doesn't just give you

22:56

heavy winds. It also gives you a surge

22:58

of water from the ocean at the same

23:00

time. And it gives you heavy rain at

23:02

the same time. These risks need

23:04

to be thought about sort of in tandem. And

23:07

I've just focused on the climate piece, but if

23:09

you're somebody interested in

23:11

energy, human health, justice,

23:13

resilience, you have to also

23:16

wonder about correlation outside the

23:18

climate system, right? Because it's

23:20

actually much worse if

23:23

the power fails during that heat

23:25

wave, because that's when people really

23:27

start to suffer, really start to

23:29

die. And unfortunately, the risks of

23:31

the power going out are also

23:34

higher during the heat wave because

23:36

you're putting more demand on the

23:38

grid. So that's another correlation, another

23:40

connection that gets outside the

23:42

climate space into society, and

23:44

we have to plan for these risks. And

23:47

whether it's reinsurers or cities

23:49

or just about anybody, we're finding

23:51

that we're more and more blind to some of

23:53

these emerging compound risks. We haven't planned for them,

23:55

and a lot of these risks are increasing

23:58

fast with climate. change. You

24:01

know, you mentioned we've talked

24:03

about some of the work that your students

24:05

are doing and I believe that you've had

24:07

some students work in this very area, right,

24:09

and compound extreme events. What

24:12

sorts of things have they found? Yeah,

24:14

so you know I've been fortunate to you

24:16

know get to work with just some fantastic

24:18

people. One that I could highlight is a

24:20

postdoc who was at Columbia until a year

24:23

or so ago named Kai Cornhuber. He's

24:25

done a lot of work on

24:27

those simultaneous heat and drought events

24:30

in multiple bread baskets. So he

24:32

looked at basically seeing how the

24:34

jet stream can appear

24:37

across the whole northern hemisphere, right,

24:39

and basically found that there

24:41

are setups where not only

24:43

will they say parts of the bread

24:45

basket of the US experience heat and

24:47

drought, but if you step back and

24:49

look at the whole northern hemisphere you

24:52

see patterns to the jet stream.

24:55

Ridges in some areas, truffs that

24:57

dip down in other areas that

25:00

become amplified, basically meaning that the

25:02

same moment in time you

25:05

have multiple regions under heat and drought

25:07

and actually other regions that are very

25:09

rainy. It's not just that you have

25:11

that extremes of temperature and

25:13

heat and drought, but also there's a

25:15

tendency for the system to get stuck

25:17

if you will. So that

25:19

any one location, bread

25:21

basket in Russia in the Ukraine, bread basket

25:23

in China, bread basket in the middle of

25:25

the US, bread basket in Europe, could

25:29

keep that hot and dry weather for

25:31

several days at a time because

25:34

of a shared feature in the jet

25:36

stream, a kind of shared risk. So

25:39

Kai did a lot of great work to

25:41

sort of help understand that risk and I

25:43

think a critical component is another thing that

25:45

he found in a paper last year was

25:48

that climate models don't do

25:50

a very good job of

25:52

capturing those patterns and

25:55

the models that we use to predict

25:57

crop yields don't do a very good

25:59

job. of simulating how much

26:01

crop yields drop if you

26:04

give those conditions, those

26:06

heat and drought to a crop model.

26:08

So there's a concern that to the

26:10

extent that people are making planning, whether

26:12

it's planning, whether it's a food security

26:15

agency, whether it's someone

26:18

ensuring food products, they don't

26:20

use climate models outputs directly, that's an

26:22

important point to make, but they often

26:24

do rely on them as one of

26:26

the data points, as they try to

26:28

look to the future, how might things

26:30

change? And if the models are missing,

26:32

some of those possible worst case

26:35

scenario, bad case scenario outcomes, we

26:37

probably don't have adaptations, we certainly

26:39

don't have adaptation strategies in place

26:41

for plausible bad things that could

26:43

happen. That's one example. There's

26:46

been a lot of discussion on

26:48

climate change attribution science, which

26:51

of course examines the causal links

26:54

between human activities, climate change,

26:56

and the impacts of climate

26:58

change. It's all rapidly evolving.

27:00

To what extent does it enable

27:03

us, does science enable us

27:05

to now ascribe impacts and

27:07

extreme events to climate change?

27:09

And has this science advanced

27:11

much recently? That's a great

27:14

question. Yeah, this is absolutely one of the emerging

27:16

areas in climate science. So

27:18

basically the way to think about it is, I

27:21

was just now talking a little bit

27:23

about using climate models to think about

27:25

the future. So imagining a world, as

27:28

we unfortunately expect, with higher greenhouse gas

27:30

concentrations, what would that mean for temperatures

27:32

for heat waves and crop yields? The

27:34

world of attribution science is about looking

27:36

at the past, looking at what's happened,

27:38

say, over the last 10, 20, 30,

27:40

40 years, and

27:43

saying, have we basically experienced a different

27:45

world or world with a different number

27:48

of heat waves, a world with different

27:50

crop yields, than we would

27:52

have if we have what we call a counterfactual

27:54

world, which

27:58

we would have had if we hadn't

28:00

increased. the greenhouse gases. So basically

28:02

the way to think about it is you

28:04

can run a climate model, but in the

28:06

past instead of in the future. Run

28:08

it once with the greenhouse

28:10

gas concentrations of the world that

28:13

is, where each year, say from

28:15

1950 to today, you had that

28:17

increase of whatever it was in

28:19

percent greenhouse gases per year. And

28:22

then compare the results to

28:24

the results that you will get with the

28:26

same climate model. If you

28:28

held greenhouse gas concentrations constant at

28:30

say their 1950 level, we can

28:32

look at both of those simulations

28:34

run from a 1950 to a

28:36

2024 that

28:40

differ only in their greenhouse gas concentrations.

28:43

If the world that is with the

28:45

higher greenhouse gas concentrations say gives us

28:47

three times as many heat waves days

28:50

over 90, has that world that could

28:52

have been that counterfactual world, we can

28:54

begin to say, okay maybe

28:56

some percentage of the heat waves

28:58

that we experienced, if we run

29:00

this into a crop model the

29:02

crop losses we might've experienced are

29:04

actually really due to the emissions

29:06

that we've seen. And

29:08

then the policy extension, you know

29:11

that you're certainly seeing in the courts not always successfully,

29:13

but a lot of cases are can we assign

29:16

damages to say the fossil fuel emitters

29:18

who are responsible for that percent. So

29:22

I sort of gave a long background

29:24

but sort of the heartier question this

29:27

field has advanced a lot Bill especially

29:29

the parts around the climate attributing the

29:31

heat events, you know in real time

29:33

we've already seen attribution studies believe it

29:35

or not talking about the heat waves

29:37

you were talking about that dome of

29:39

heat from the middle

29:41

East sort of all the way to

29:43

the Philippines and Indonesia. There've already been

29:45

attribution studies of that. The real advances

29:47

are in the impacts now where we

29:49

try to say, okay but what about

29:51

crop yields? What about human health? That's

29:54

one of these frontier areas but

29:56

we're starting to see more and more studies. And

29:58

for example, for health we have seen studies saying

30:01

X many more deaths that actually occurred

30:04

were due to fossil fuel emissions. There's

30:07

always uncertainties, assumptions, but

30:09

there's also a big signal too. It

30:13

just seems so important, not only for those

30:15

considerations you just mentioned, looking farther out

30:18

into the future to try to understand

30:20

impacts, but I think also just to

30:22

help public understanding of climate change because

30:24

people will also ask when they see

30:26

harsh weather, how is that climate change?

30:29

Some people may automatically assume,

30:31

yeah, the cause is climate change,

30:33

where in fact, climate change

30:35

may be an attribute, but there's other factors

30:37

that went into causing the bad weather at

30:39

the moment. I

30:41

think it's important for the explanation

30:44

of climate

30:46

science to the general public and

30:52

the public understanding. That's right, and

30:54

the role, for example, in real

30:56

time of meteorologists can be hugely

30:58

important. An individual hurricane

31:00

strikes one location that is

31:03

mostly going to be the

31:05

kind of random piece. It's

31:08

not going to primarily be about climate change.

31:10

There might be some piece of it that

31:12

you can say is due to climate change.

31:14

Sea levels have risen some as the

31:16

oceans have warmed and as ice has

31:18

melted, causing the flooding from

31:20

that hurricane to go a little further

31:22

inland. But fundamentally, one individual storm is

31:24

largely going to be the random piece.

31:27

For a big heat wave, it

31:29

can be different though. We can really have

31:31

even for one event that signal emergence. So you're

31:33

absolutely right. The other piece there that you're

31:35

alluding to is human nature. It's

31:37

human nature to care, to engage around

31:40

something that's right in front of us

31:42

that we can see happening to us

31:44

now. Whereas sadly, something

31:47

in the 2050s, no

31:49

matter how dangerous, deadly, it's likely

31:51

to be some people are

31:53

still, because it's not right in front of their

31:56

eyes, it doesn't really

31:58

connect or resonate for them. The

32:00

European Climate Agency, Copernicus,

32:03

said the year 2023 was 1.48 degrees

32:05

Celsius above

32:09

pre-industrial times. And

32:11

that's barely below the 1.5 degrees

32:15

Celsius limit that the world hoped to stay

32:18

within under the 2015 Paris

32:20

Climate Accord to avoid the most severe effects

32:22

of warming. Are we reaching

32:25

a tipping point? Yeah, great question. So I

32:27

mean, I think just an update

32:29

on that data, if you go from, I think,

32:31

May 23rd through April 24th.

32:34

So if it still took a year but

32:36

started five months later, it's actually 1.61 degrees

32:38

Celsius above

32:42

instead of 1.48. So

32:44

just reinforcing that point. If

32:46

you read the fine print of these earlier

32:49

IPCC reports, they

32:51

never said that no

32:54

single year would go above 1.5. It

32:56

was more like an often unstated sort

32:58

of 10-year average. But to me, that's

33:01

really the fine print. The bottom line

33:03

is we are seeing

33:05

this warming happening faster than we

33:07

thought. And again, towards some of the

33:09

things I alluded to earlier, the

33:11

really big takeaway for me, though, is

33:14

that I believe we have underestimated the

33:16

societal impacts, the damage caused by one

33:18

and a half degrees. That

33:20

is the biggest issue. If you go, I mean,

33:23

they're all huge issues. But that to me

33:25

is the most fundamental piece. If

33:27

you compare the most recent IPCC

33:29

report to the prior one, this

33:31

is getting kind of wonkish, but they have

33:33

a figure sometimes referred to as the burning

33:36

embers, where on one axis,

33:38

the y-axis, you have the amount

33:40

of warming. And

33:42

then you basically see these colors ranging

33:45

from yellow to reddish and purple for

33:47

these critical systems, food

33:50

security, human health, coral

33:53

reefs, and basically a

33:55

couple IPCC reports ago, if you look

33:57

at an amount of warming, like one and a half or two degrees,

33:59

it's A lot of those

34:01

essential systems flashed yellow at

34:04

that amount of warming, which means

34:06

serious risks, dangers, but

34:09

now a lot of those systems, and this is just

34:11

the assessment of the experts, right? At

34:14

one and a half degrees are flashing red. In

34:17

just five or six years, the

34:20

experts, the impact experts have

34:22

profoundly changed their assumptions. They're now saying that

34:25

the risks associated with one and a half

34:27

degrees of warming are far higher, reaching

34:30

levels where we may not be able to adapt

34:32

to this, at one and a half degrees of

34:34

warming. Tipping points, a

34:36

very fraught topic.

34:38

The basic idea is nudge

34:41

a system, and it behaves,

34:43

for example, by turning up

34:46

greenhouse gases. It behaves in a predictable

34:48

way for a while. If you

34:50

were to take away the greenhouse gases, which we

34:52

haven't been able to do, you'd

34:54

expect that system to slide

34:56

back to where it was. A

34:58

tipping point is the idea that the

35:00

more you push that system, turn up

35:02

the greenhouse gases, turn up the temperature,

35:05

at some point, the behavior totally changes.

35:07

And if you stop pushing, it doesn't

35:10

go back to where it was because

35:12

you, for example, removed all the sea

35:14

ice from the Arctic instead of a

35:17

surface that used to reflect

35:19

sunlight, a white surface, you now have

35:21

an open water where the ice used

35:24

to be that absorbed sunlight. It's fundamentally

35:26

a hotter system, and

35:28

the basic dynamics have changed. The

35:30

hope is that we haven't crossed any of these

35:32

tipping points yet, but I can tell you for

35:35

sure that there's far more concern than there was

35:37

before about ocean circulation,

35:39

for example, about the Amazon

35:42

rainforest, you name it. There's

35:44

major concern emerging across a

35:46

variety of systems. You

35:49

talk about impacts and your concerns

35:51

over the impacts of

35:53

these patterns, atmospheric patterns, severe weather at

35:55

all. I

35:58

was reading about the storms. that hit

36:00

Houston recently cost the city billions

36:03

of dollars, or

36:06

will cost the city billions of dollars

36:08

to recover from these deadly storms that

36:10

sent hurricane force winds through the city's

36:12

downtown. This happened a couple of weeks

36:14

ago. How well

36:16

or poorly are cities, coastal

36:19

regions, and other areas adapting

36:21

to climate impacts? So

36:24

I think we're way behind in

36:26

our adaptation. It does

36:28

need to be noted that efforts

36:30

are being made, right? Whether it's New

36:32

York City, New York State, much

36:35

of California, there are, and many

36:37

parts of Europe and other places,

36:40

cities, states, and countries

36:42

are trying to protect and protect

36:44

their most vulnerable. But we're clearly

36:46

sort of caught behind the curve

36:48

as we're seeing these extreme events

36:50

happening more quickly than we thought.

36:53

And when we don't have the resources to invest

36:56

at the level we need to in adaptation, and when

36:58

we have a tendency not to

37:00

protect our most vulnerable populations, even

37:03

before you bring in the variable of

37:05

climate change. So it's sort of a

37:07

complicated story. I think there's a lot

37:09

of good faith efforts and exciting things

37:11

happening in the adaptation space, whether

37:14

it's, for example, private sector

37:16

companies that are starting to, and

37:18

cities, that are increasingly protecting their

37:21

workers. Some are

37:23

going so far as literally having

37:25

them sort of swallow devices that

37:27

help detect how

37:29

the body is responding to heat. You're

37:32

seeing companies offering more breaks,

37:35

sometimes providing cool, like vests, that literally

37:37

cool their workers. So we can point

37:39

to all sorts of important and

37:42

exciting initiatives and efforts to think

37:44

about the future, but that is

37:47

a very, very different thing than

37:49

actually meeting the challenge head on.

37:52

You mentioned that stuff's taken to protect workers,

37:54

but I mean, it's only now that the

37:56

US government is apparently

37:59

on the verge of... a rule that would

38:01

require employees to protect work

38:03

as exposed to high temperatures. It would be

38:05

the first such rule, as I understand it,

38:09

from the federal government, and

38:11

it's expected to meet some resistance from

38:14

some business and industry groups. So it seems

38:16

there's still a lot that needs to be done

38:18

along those lines. For sure, absolutely. And maybe

38:20

a little bit of this is sort of what

38:22

we were talking about earlier, if you

38:25

need to see it visually right

38:27

in front of your eyes for a lot of people

38:29

to appreciate it. And if

38:32

you look a little below the surface, it's

38:34

obvious that heat waves are killing

38:36

people. They're affecting our economic productivity.

38:38

But sometimes you don't see the

38:40

heat wave the way you see

38:42

those hurricane force winds, or see

38:44

the rain, or see the snowstorm.

38:47

And historically, when you look, for example,

38:49

at heat deaths that are recorded by

38:52

governments, a lot of the

38:54

people who are dying, it was not listed as

38:56

a heat death, right? This is somebody who had

38:58

a heart condition, kidney issues,

39:00

respiratory issues. The

39:02

deaths or the hospitalizations would be

39:05

listed as a preexisting health condition.

39:07

But it's much more nuanced, right?

39:09

The heat is often the thing that is tipping

39:12

that over towards the death. So I sort

39:14

of lost the thread a little bit, but

39:17

bottom line is, yes, you're absolutely right that

39:19

not enough has been done for a

39:22

variety of reasons. And there's sure to

39:24

be resistance if there's anything that we've

39:26

learned. But hopefully describe the risks enough.

39:30

And as people start to advocate, we'll

39:33

see things moving in the right direction as maybe they are in

39:35

some ways. For example, on the

39:37

emissions reduction side with say

39:39

renewables and things like that. And

39:42

yet, they say heat kills more people

39:44

than hurricanes, floods, and tornadoes

39:46

combined. I'm recalling to the

39:48

book I read last year with Jeff Goodell's book,

39:50

The Heat Will Kill You First. It

39:53

was a rather alarming

39:55

account of, as

39:58

he put it, life and death on a scorched plate.

40:00

But we had them on the show last summer and

40:02

it was a insightful discussion that we had. You know,

40:05

here's some, maybe some good news on

40:07

this whole front and that has to do with

40:09

you and some of the research that's done there

40:12

at Columbia and by some other universities. And

40:15

I understand you're involved in one effort

40:17

called the Consortium for Climate Risks in

40:20

the urban Northeast. And

40:22

it includes Columbia and some other universities.

40:26

And I was looking into

40:29

this effort, said the consortium says

40:31

on its website that areas of

40:33

the Northeast US are

40:36

at the vanguard of resilience efforts

40:38

in part due to involvement of

40:40

consortium scientists in the region's cities.

40:43

Tell us about those findings. Yeah.

40:45

So basically, the Northeast, for a

40:47

variety of reasons, I think has

40:50

engaged pretty early in developing adaptation

40:53

plans. New York City's panel on climate change

40:55

has been around now for about 15 years.

40:58

Philadelphia is starting a major initiative.

41:01

Boston has done a lot in the way

41:03

of resilience, as have the states, Massachusetts and

41:06

New York under the NYSERDA program,

41:08

really at the vanguard looking at these

41:11

risks. Increasingly, though,

41:13

we're starting to say, you know, it's

41:15

not enough just to look at the

41:17

city scale, just to look at your

41:20

infrastructure, your transportation, your electric grids. We

41:22

got to also look at what's happening

41:25

in individual communities, vulnerable communities. And maybe

41:27

I'll just quickly highlight sort of one

41:29

piece there. One of my colleagues in

41:32

CC Run is

41:34

Franco Montalto from Drexel University

41:36

in Philadelphia. And

41:38

he, not alone, but working with

41:40

community members and others, pioneered

41:43

with them an effort, I

41:45

think about two years ago during the pandemic, to

41:48

go at the block scale in some

41:51

struggling neighborhoods in Philadelphia and basically work

41:53

with the people who live on that

41:55

block saying, how are you affected by

41:57

heat extremes? And what types of

42:00

ads? adaptations would you like to see at

42:02

the block scale, the kind of things that

42:04

individuals properly supported can do.

42:07

And basically they actually within the course

42:09

of a summer didn't just plan, they

42:11

actually took individual steps to provide additional

42:14

shading where trees were missing,

42:16

other types of canopy to increase

42:19

plant cover. Relatively small

42:21

steps individually, but important ones

42:24

that are very individual led. They can

42:27

also increase that sort of feeling of

42:29

empowerment and the idea that across a

42:31

range of scales, people need to be

42:33

really concerned about these extreme events, but

42:36

also there are steps they can take

42:38

working across scales to reduce the risks

42:40

a little bit. You know, Bradley, I

42:42

recall from our last conversation that you

42:45

were not nearly as concerned about

42:47

the state of climate science. You

42:50

felt it has been, you know, for the

42:52

most part abundant and sound still has ways

42:54

to go, but a lot of progress

42:56

has been, is being made there. You

42:59

were more concerned about the need to communicate the

43:02

science to the public. You know, you felt

43:04

people need to be, to better understand the

43:06

impacts of these changes. Do

43:09

you still feel that way? And

43:12

if so, what are you and other

43:14

scientists doing about that? It's

43:16

a really good question. I mean, I think, you

43:18

know, you're sort of pointing at a

43:20

bit of a paradox in what I'm

43:22

saying, because on the one

43:24

hand, I completely agree with, I guess what

43:27

I said and what you said, which is

43:29

basically we've known for a really long time

43:31

that we were gonna see this warming, see

43:34

the sea level rise, and

43:36

that there was gonna be a profound

43:38

change in the frequency, say, of extreme

43:40

events, heavy rain, drought, floods.

43:44

In a way, I was making the case that we

43:46

don't need to know exactly how much heat waves are

43:48

gonna change. We don't need to know if they're gonna

43:50

be 1.8 times as common or

43:54

2.5 times as common in the future. It would

43:56

be nice to know that. It would help with

43:58

planning, but that's not the first. First order

44:00

uncertainty, right? What we really need

44:03

to do is mobilize as a

44:05

society to invest in adaptation, to

44:08

invest in emissions reductions, right? So I

44:10

think I was pointing to the idea

44:12

that the climate science is further advanced

44:15

than some of these other pieces.

44:17

And if we engage social science,

44:19

what motivates people? Psychology, what

44:22

are the impacts across vulnerable communities?

44:24

How does, you know, huge issues

44:26

like migration, conflict play into all

44:28

this? What motivates people?

44:31

Is it optimism? Is it pessimism? I

44:34

think we need much more effort in

44:36

those areas than we do in

44:39

sort of new climate science. I

44:41

said that then, and I would

44:43

say that now, but I

44:45

think it's two things. One, it's a bit of an

44:47

all of the above. We also need more climate science.

44:49

And if we sort of circle back to what we've

44:51

been talking about for most of this call, there

44:54

is this other thread, which is, yes,

44:58

we've had this range of predictions for

45:00

temperature heat waves for a while, but

45:03

I am leaning into this idea that

45:05

we may have underestimated how extreme they

45:07

could be. And that is new science.

45:09

And I think that's an important new

45:11

science from a risk management perspective. Because

45:13

even if, you know, there's less than a

45:15

50% chance that I'm right, even

45:17

if there's only a 5% chance that I'm right,

45:20

the impacts are catastrophic, right? So we

45:22

need to plan for those

45:25

possibilities. Radley, you say you learn a

45:27

great deal from your students, that they

45:29

make you feel more optimistic about the

45:31

future. I've read

45:33

where you've said, quote, "'Their solution-oriented

45:36

results provide "'a welcome counterpoint to

45:38

the often depressing "'breaking news and

45:40

climate change.'" And well,

45:42

we've been discussing some of that depressing

45:45

breaking news today. What

45:47

is it that your students are doing or saying that makes

45:49

you feel this way? Focusing

45:51

in on the ways that they can

45:53

help, the ways that they can work

45:55

on solutions, even if it's, you

45:57

know, just biting off a narrow piece of

45:59

this. It

46:01

might be ways that they can help a city

46:04

pick the right adaptation projects.

46:07

It might be ways to contribute to

46:09

emissions reductions. And one thing

46:11

I'm really excited about is some work

46:13

on climate justice. For three semesters I've

46:15

been taking senior undergraduates down to Jackson,

46:18

Mississippi, where

46:21

they're learning about the decades and longer

46:23

history of racism, lack

46:27

of investment in

46:29

Jackson that has left communities

46:32

frequently flooding and also

46:34

having a real water crisis. And

46:36

these students could easily just step back

46:39

and say, the problems are too big.

46:41

They're too systemic. How could we in

46:44

a semester as undergrads do anything

46:46

about it? But instead the students

46:49

approach is, let's go down

46:51

there, let's talk to these communities, let's listen,

46:54

let's build relationships. And

46:56

even if it's a relatively small piece based

46:58

on where they feel that we can help

47:00

them by working together, let's

47:02

engage. Maybe it's

47:04

helping develop a communications plan

47:06

to bring those communities together

47:09

to increase activism. Maybe

47:11

it's helping identify what the components

47:13

could be of a flood mitigation

47:15

plan for those communities. The

47:18

students look to act and they look to

47:20

learn and listen. A

47:23

couple other quick examples. Students

47:25

have changed so much. Ten

47:27

or 12 years ago I didn't see

47:29

any students that were picking their college

47:33

based on whether it was focused on

47:35

reducing its own greenhouse gas footprint. Now,

47:38

it's still a minority of students, but that's

47:40

starting to become a factor for some of

47:42

them. And certainly when you ask, what do

47:44

they want their first job out of college

47:46

to be? Where do they want to invest

47:48

their money as they get further

47:50

into their 20s and 30s? No

47:53

denying the idea that they want to

47:55

be increasingly working with

47:57

communities that are committed to reducing a means.

48:00

emissions, to protecting their

48:02

workers from these extreme heat events,

48:04

protecting their supply chains. There's a

48:06

growing understanding that, you

48:09

know, it's almost a kind of free

48:12

riderism, the companies that aren't doing those

48:14

things, and an expectation that they're increasingly

48:16

going to be punished, those kind of

48:18

companies. It's just sort of a losing

48:21

strategy to be investing or working in

48:23

places that aren't asking

48:25

the climate question, if you will, and aren't

48:27

thinking about justice. I'm oversimplifying a bit, right?

48:29

It's a broad world. Not everyone's thinking that

48:32

way. We know there are political factors that

48:34

can push in the other directions, but it's

48:36

been a sea change relative to 10 years

48:38

ago, nonetheless. Yeah, it's so

48:40

encouraging to hear that. I always find, you

48:43

know, important to hear the stories

48:46

of students these days and what they

48:48

take serious and their outlook on the

48:50

world, and even more importantly, how they're

48:52

acting on it. It's

48:55

important. It's a great idea, and it does

48:57

give us a measure of optimism as we

48:59

sort of sort through all these difficult issues.

49:01

Radley, thanks for joining us again on Columbia

49:04

Energy Exchange. Great to see you again, Bill.

49:06

Thanks. That's

49:10

it for this week's episode of Columbia

49:12

Energy Exchange. Thank you again, Radley Horton,

49:15

and thank you for listening. The

49:17

show is brought to you by the

49:19

Center on Global Energy Policy at Columbia

49:21

University's School of International and Public Affairs.

49:24

This show is hosted by Jason Bordoff

49:26

and me, Bill Loveless. The

49:28

show is produced by Aaron Hardick

49:30

from Latitude Studios. Additional

49:32

support from Lily Lee, Caroline Pittman,

49:35

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49:37

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49:40

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49:47

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50:04

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