How can we use the things we share in common to address some of the most challenging problems facing the world? This course examines issues concerning poverty, the environment, technology, health care, gender, education and activism to help us understand better how to initiate positive change.
Conversation with a Climate Economist on Risk Management
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來自 Wesleyan University 的課程
How to Change the World
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Climate Change and Sustainability
Discussion about political and economic ramifications of climate change, including how to think big about sustainability
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Michael S. Roth
[MUSIC]
>> Good morning.
I'm here this morning with Gary Yohe, the Huffington
Professor of Economics and Environmental Studies here at Wesleyan University.
And we're going to talk about climate change and sustainability.
And Gary, I'm delighted you're able to join me this morning.
>> It's a pleasure, thank you for inviting me.
>> It's, the pleasure's mine, we let's get right into it.
The the framework for this course for which we've talked a little bit about off
camera is.
to, to have our students who are scattered around the world.
Two thirds of the students in this class will be outside the United States.
And, we're, we're trying to hit three notes.
What do we know? Why should we care?
And what can we do?
And so let's start off to talk a little
bit about, what do we know now about climate change?
>> We know a lot about the science. Not everything, but a lot.
We know that the planet is warmed
about a degree centigrade since pre-industrial levels.
We know that from thermometers and other points of data.
And we know that it's very unlikely that the current climate
and the past climate were generated by the same climate system so
the old one was broken.
We have no idea what the new normal is,
but it's not eqivocal that the planet has warmed.
>> Is that, is this something that one
expects to happen every several centuries or something?
In other words, are these, I mean, the planet has gone through
different cycles of climate change and, and is, what's different about this one?
>> What's different about this one are two things.
One,
it's happened much more quickly than it's ever happened before.
And secondly there are bits of evidence from a variety of model exercises
that say that a good deal of the driver of the warming has been human influence.
>> Yeah.
>> The emissions of greenhouse gases. >> And that's our focus in, in this
class is really, how how we have changed the world inadvertently or
without realizing what changes we were creating.
And how we can, be more intentional about the
changes we want to see occur in the world.
So the, the planet has warmed already.
And what's the trajectory that the scientists see coming?
>> Well, th, there, there are a couple of points there.
One is that the warming that we've seen is
only half of the warming to which we've committed ourselves.
So that the one degree that we've already seen, has another one
degree built into the system that there's nothing we can do about.
>> I see because it's already in process.
>> Uh-huh.
And there's enormous amount of inertia in the climate system.
The heat gets built in.
>> Right.
>> The response in ambient air temperature or
ocean temperatures and things like that, have significant lags.
>> Right.
>> But we are committed to that, if we [SOUND],
if we eliminated greenhouse gases admissions tomorrow, we
would still be committed to another degree of warming.
>> Mm-hm, mm-hm.
And, if we eliminated greenhouse gases tomorrow, and we had
that degree of warming would we then see a cooling?
>> No.
>> I see so it's that, that becomes the new normal?
>> That, that well that begins to define the new normal.
Part of the new science I'm told is
that long run equilibrium temperature of the planet is determined by a
couple of decades of the maximum concentration of greenhouse gases.
So among the implications to that is we're
already about 450 parts per million in CO2 equivalent.
>> Mm-hm.
>> We have committed to a certain
amount of temperature increase associated with that.
From an economist's perspective, going back to
350, apologies to Bill McGiffen, wouldn't buy us a thing.
>> Mm-hm.
>> the, the rate at which the long run temperature, once
it's achieved depreciates over time is in orders of centuries or millenia.
>> I see.
And how did you as an economist get into this field?
I mean this is a field for climate scientists
and biologists and you know, people doing evolutionary science.
Tell me a little bit about how an economist enters this domain.
>> Well my personal story started at about 1981.
One of my thesis advisors Bill Northouse at Yale, invited me to
become part of a National Academy of Sciences study called Changing Climate.
It seemed like a good idea at the time, so I said yes.
And we produced a report in 1982.
Our contribution was thinking in the aggregate about the
economic activity that drives the emissions of greenhouse gasses.
>> Mm-hm.
>> Along a variety of, of futures, which we
can't predict which one, but what was the range?
And we produced what were affectionately called spaghetti graphs.
Just a whole series of possible trajectories.
>> I see.
>> Of what the emissions would be, and back
then we had a very simple model that could
translate that into concentrations, and translate that into temperatures,
but that was about as far as it went.
After that I began to worry about some other environmental problems applying
the same methodology like CFCs and ozone depletion and things like that.
>> What, what's CFCs?
>> Chlorofluorocarbons. >> Right.
>> And then began to worry about impacts and how to calibrate those.
And then began to worry about adaptation.
How you could ameliorate the impacts by responding to certain things
and what were the underlying determinants, of the capacity to adapt.
>> And [COUGH], and the, what we've learned since those early days is about
the trajectory of warming. And what other major advances
in what we know about climate change have you
seen since those early days of the spaghetti graphs?
>> We don't know a lot more about how to project what the future
is going to be, so we're still dealing with the full range of possibilities.
We've learned a lot more about how various strata in societies
and various countries around the world might be able to respond.
>> Mm-hm.
>> Both with respect to reducing emissions and
also with respect to adaptation and reducing vulnerability.
>> Mm-hm.
The major disc, the major conclusion of the fourth assessment report of
the Intergovernmental panel on climate change was that this is a risk problem.
>> Right.
>> Its not a cost benefit problem, and
so risk is likelihood times consequence and it depends
on co-benefit, damages, attitudes towards equity.
>> Right
>> Things like that.
But what that conclusion meant, and it was
unanimously agreed to word for word by 196 countries.
In a plenary meeting of the synthesis report for the fourth assessment
report, is that our clients in the IPCC wanted to know that risk.
They wanted to know about likelihood and
consequence, and we no longer had to focus our attention on what we knew a lot about.
>> Mm-hm.
>> We could talk about conclusions that, for which we had lower confidence.
If we could tell us a story that the con, or, lower
confidence but tell a story that the, consequences could be really quite severe.
>> Hm.
>> So instead of being fear mongering we were
now, addressing the needs of the, of the clients
that we had.
The National Climate Assessment has adopted risk management.
The America's Climate Choices Academy reports adopted that perspective.
>> Mm-hm.
>> The other keyword is iterative, we finally figured out
that nobody's going to write climate policy for a 100 years.
>> Yeah.
>> And so you have to figure out
what to monitor, how quickly to make the adjustments.
And what those adjustments would depend on.
>> So I, I want to come back to this to
this change to, to the paradigm concerned with risk,
so to make sure everybody understands that, that transition.
But before we go there I, I know you,
you've dealt with these kinds of folks over the years.
What do you say to people who say you know, this, it's really cold and
where I'm living or you know, the, it's, you know that how can you say the
climate change brings flooding and drought?
I mean.
>> Mm-hm.
>> People who use their own local perception as a point of
resistance to the, to this kind of more global sense of, of change.
>> That is sometimes a difficult conversation,
but there's two ways of going about it.
One is for people who are skeptical of the whole idea.
>> Mm-hm.
>> How do you know humans are causing it?
>> Right.
>> And that is in fact model based.
>> Right.
>> We don't have a parallel planet where we can do the controlled experiment.
>> Right.
>> So we have what we have. and,
very high confidence that humans at this point are, are causing a good deal of the
warming that we've, that we've observed. Are we absolutely sure?
No. >> Right.
>> But we're 95% sure. >> Yeah.
>> And so you get in these conversations with guys
like Fred Singer who's a, who's a, a global skeptic.
And said, you know, Fred, how sure are you that you are right?
>> Yeah.
>> And, at one point in, in a conversation,
in my office, he said, well, I'm 95% sure.
And then you say, well, for risk-based framing, all I need is that 5%.
>> Right.
>> And, so you know.
And then I asked him why he was so afraid of, of some
interventions that would reduce the, the
the pace of emissions of greenhouse gasses.
And he said, because they're going to be so expensive.
How do you
know that? From economic models.
And then you get to look at him and say you believe economic models
>> [LAUGH] Right.
>> More than you believe climate laws? >> Yeah.
>> So that's, that's, that's one, one way of, of approaching that,
that problem. a, another way is to simply say that
once you accept it as a risk problem, businesses, human beings,
communities, families deal with risks all the time.
>> Right.
>> They buy insurance, they do this, they do that.
Sometimes they're required to do it.
Sometimes they do it because they think it's a good idea.
All we're saying now is that climate is another source of risk.
Another source of uncertainty in their lives.
>> Mm-hm.
>> And what you are seeing, is a pattern of
the change in the frequency and intensity of extreme events.
>> Right. >> Of all sorts.
>> Yeah.
>> So you get higher precipitation in short periods of time.
>> Right.
>> in, interrupted by long periods with almost no precipitation at all.
So we can get flooding,
>> Mm-hm And then droughts.
>> Droughts, right. >> and, so on and so forth.
[BLANK_AUDIO]
>> So in, in thinking about the, the transition to risk, I just want
to make, over the model, the modeling of risk I want to make sure
that, I understand, and our students understand the, that changed.
Because it seems really fundamental that at some point, there was this, you know,
the fear mongering was, was well, it was based in, in the science, right?
I mean, it was, it's really scary.
But it, it's, I guess that it's, you
said it's certainly going to be bad, and, and people
will say, well aha, this wasn't as bad as you said it was, and so then, they'll,
you'll throw out the whole science, and now
we're moving to a different model which, which, is
it, is it more, would it be more fair to say it would be more probability based?
Is that the, is that how we should think about it?
>> Absolutely. It is probability based,
but it can be subjective, and it doesn't have to be quantitative.
>> Hm.
>> The risk based approach is a way of organizing your thoughts.
It tells you to think about consequences and think about likelihood.
>> Mm-hm.
>> And so in the New York panel on climate change for, for Mayor Blomberg,
>> Right.
>> There was an acceptance of the risk based
framing push back that we don't have all these probabilities
>> Mm-hm.
>> We can't calibrate the consequences and stuff.
So, we created this thought organizing matrix that had
level of consequence on one axis and likelihood on another.
>> Right.
And, there were a variety of people in an adaptation task
force for the mayor from private sector and from various agencies.
He had been mayor for a long time.
>> Right.
>> So everybody played nice [LAUGH] in the sandbox.
And they were asked to look at the
infrastructure over which they had control, and authority.
And think about projections, a wide range
of projections of how the climate might change.
And think about what the vulnerabilities would be to
tho, their infrastructure, over time with those, those particular scenarios.
Not quantify them, just them in dots.
>> Right, right. >> In, in this, in this matrix.
This,
and that's very subjective, they all went back to their offices and did it.
So the thing that made it work was they
all came back and presented it to each other.
>> I see.
>> And so they came up with a relatively consistent view
of the subjective judgement of what's very likely, and what's unlikely.
>> Mm-hm.
>> What's high consequence and what's low consequence.
>> Right.
>> And then they had to go back and think about how they would respond.
And when.
And came up with 450 different adaptation ideas
>> Really.
>> Across the private and public sectors in New York City.
Costing tens of billions of dollars if they wanted to do that.
>> And these are adaptation ideas, do they, does that mean they're not about
carbon emissions but they're about how to deal with the effect of the changing.
>> Exactly.
>> Can you give us some examples? >> well,
flooding the subways. >> Right.
>> One of the things that, that they observed was that back in
the 90s, the sub day, the subways might flood every three or four years.
In the late 90's it was sort of once a year.
In the early, part of this century, it was more like
four or five times a year, and the floods were getting worse.
>> Right.
>> This was not from coastal storms or anything.
>> huh.
>> This was from extreme precipitation events.
And there's not a lot in New York City that absorbs water.
>> Right.
>> I mean, it just runs down into the drains and anything.
>> Yeah.
>> Anything that's open.
So they began to think about how to protect
the subways and how to protect the infrastructure underground.
Verizon did exactly the same thing, cause all of their
>> Yeah.
>> Their, their cables were underground.
And they had to worry about those sorts of things.
There was
I'm told, a story where the, the person who was designing the
new World Trade Center came to the scientists on the panel and
said, I can rotate this thing fifteen degrees if you could tell
me how the prevailing wind in a big storm was going to change direction.
>> We had no idea.
[LAUGH] We said sorry, can't help you.
>> Wow.
>> So, so he put it up the way, the way he wanted
to do it.
Then we started to think about extreme events and one of the things that I think
we can claim is that we saved lives in anticipation of Hurricane Sandy.
>> Mm-hm.
>> because the mayor shut down the subways,
>> Right.
>> Ten hours before Sandy made landfall.
And the MTA moved all of the trains to higher grounds,
>> Right. >> So they weren't in the tunnels.
The estimate is when the tunnels flooded, there would've
been ten trains with ten cars each, 100 people
in each car, in the subways and that's 10,000
people that were, would've been in really extreme risk.
>> Yeah.
That's a great example and, and so the why we should care question becomes why
we should care about this, instead of like why should we care in general, let's say.
>> Mm-hm. >> Like why do you care about flooding
why do you care about tornadoes and that will depend on where you
live, what the nature of, I guess like any other kind of insurance question.
what, what is what is my situation and how do I want to
protect myself against really extreme danger even if it's not that likely.
>> Well this I mean, one of the
new things recently is this concern about adaptation
and, and the acceptance of that is something to
think about for a very long time the environmental community.
Wanted to resist talking about adaptation because it
sounded like you were giving up on the problem.
>> Yes.
>> And, and since it's already starting to happen, we're seeing changes in, in the
frequency of droughts, and floods, and wildfires
from pine bark beetles, heavy precipitation in local
areas causing flash flooding sea level rise makes the manifestation of
any coastal storm more severe when it makes landfall, not just hurricanes.
>> Right.
>> Those sorts of things are starting to become recognized by people
so they get to think about, what it means in their lives.
extreme, but by the way it, extreme precipitation when
it happens in the summer is a huge downpour.
I have a little rain gauge on my deck, over, over in Portland.
And two years ago in the summer, we got
four and a half inches of rain in 35 minutes.
>> [LAUGH] But when it happens in the winter it's snowstorm.
>> Right.
>> And so Senator Inhofe will go out and
build an igloo and said this is Al Gore's house.
And how could we have global warming cause we have all this snow.
Well a hallmark of climate change is a change of
intensity of these precipitation events that happens in the winter.
It's white.
>> Yeah, [LAUGH] Yeah.
So, so, the question of risk in, vulnerability.
It reminds me of my years in California when, when people
really tried to understand how much you should protect against an extreme
earthquake, or earthquakes of various kinds, right?
Which, you don't know when they're going to, but it's likely
over certain range of time you're going to have some of these
events and, and how do you protect yourself against the worst
ones or or how do you choose how to protect yourself?
Now, the difference I guess was climate change is that
we're, we don't know that we're doing anything to cause the
increased likelihood of earthquakes. >> Mm-hm.
>> We're only focused on mitigation there or adaptation.
To living in a seismically active zone.
and, and people of course spend billions of dollars to
protect against these events, and, and with already some success.
But they are not trying to reduce seismic activity.
Do you worry about the, the, like, taking one's eye off the the goal of,
of, of reducing emissions, because we're, we focus very much on a, adaptation?
>> No I don't, actually, I, I've notwithstanding lack
of action at the Federal level in the United
States, there are regional Carbon emissions programs, Reggie in
New England and California has its own cap and trade.
>> Right.
>> There's some in the Midwest.
People are beginning to worry about that.
But that, that's more a government problem
and a policy problem, and it involves pricing
carbon and investing in alternative energies and things like that.
So there's a real role for the public sector in that.
The adaptation stuff is one, necessary because we're already seeing this stuff.
>> Yeah.
>> And two, it can go down to the local level.
When we had, couple of years ago we had, remember we had those big snow storms.
>> Yes. >> One after another.
I ended up with four feet of snow on my roof.
>> Mm-hm. >> And I had four or five guys
up on my roof shoveling that off. The roof was about 20 years old.
They had steel shovels and they did some damage so it was time to change the roof.
>> Right.
>> But I remembered the extreme precipitation
event, so when we changed the roof.
Put on new gutters, and I put commercial
size gutters on instead of res, residential size gutters
>> Yeah.
>> To handle the excess water that happens every,
every once in a while.
Cause with the regular sized gutters it was just overflowing.
>> Yeah.
>> Going down next to the foundation and ended up in the basement.
That wasn't so good. >> Yeah, right.
>> So this works better, gets the water in the backyard.
>> So, these kinds of
adaptations can take place at every
level, from the personal, to
the, to the governmental.
