Transcriber: Amanda Chu Reviewer: Peter van de Ven
So I'm here to talk with you today about a set of ideas
that are, in some ways, pretty deplorable.
This is a conversation that, by rights, people shouldn't be having
and a set of ideas that, by rights, people should not be contemplating,
but these ideas have become so important so quickly
and will prove to be more important moving forward
such that we can no longer ignore this conversation.
Today I'm going to talk about climate geoengineering.
Now climate geoengineering is a phrase that may not be familiar to all of you.
It's a blanket phrase
to encapsulate a set of imagined technological responses to climate change.
The sorts of responses I'm talking about
are those that might suck carbon dioxide and other greenhouse gasses
out of the atmosphere
or that would reflect some amount of the sun's rays back into space
before they can warm the planet.
So I'm not talking about technologies like renewable energy.
I'm not talking about sea walls
as an adaptation measure to climate change.
I'm talking about things like dumping large amounts of sulfate particles
into the stratosphere
to act as a reflective layer to reflect solar radiation.
I'm talking about dumping huge amounts of iron into the world's oceans
to bring about vast carbon-inhaling blooms of phytoplankton,
the idea being that these blooms of phytoplankton
would then soak up carbon
and take it down to the bottom of the oceans for long-term storage.
This is the stuff of science fiction.
And for the longest time,
people who espoused these sorts of ideas and talked about them
were way out on the fringes of the climate change conversation -
as one author put it,
they were Strangelovian scientists,
mad scientists,
who are giving us ideas that would never pan out and made no sense.
But in the last handful of years, the conversation has been shifting.
We need to pay attention to this for two reasons:
These sorts of ideas are gaining traction
because there are large-scale
and very powerful social and political and economic processes
pushing us towards development and deployment
of these sorts of technological responses.
The second reason we need to pay attention to climate geoengineering
is because we might reach a point where we need to use this stuff.
Now that this is going to be ultimately an unsatisfying talk,
in the sense that I can't tell you
climate geoengineering is a good idea or a bad idea;
in fact, it's kind of crazy to try and make that determination.
But what I want to do is to lay out some of the ways
that we need to think about these technological responses
so that we can more effectively engage with whether or not this is a good idea.
To get there, let me just tell you
a little bit about how I got interested in climate geoengineering as a topic
and how I got interested in environmental concerns.
So I grew up in New Zealand;
my accent's getting pretty muddled by this point,
but you might still get a hint of the southern hemisphere
in the way that I speak.
Like many people from in New Zealand,
the many environmentalists,
I can point to lots of good times in the out-of-doors
as a kind of a defining moment in my life that drew me to environmental causes,
but more than that,
the thing that really got me interested in the environment
was learning when I was in primary school, in elementary school, in New Zealand,
why fair-skinned people in New Zealand
had to pay particular attention, when they go outside,
to putting on sunscreen and wearing sun hats and so forth.
Part of it's because New Zealand's a very sunny country;
we spend a lot of time outside.
But part of the reason we need to be so careful
is because there are these gases,
invisible gasses called chlorofluorocarbons, CFCs,
which were being produced and are produced mainly in rich northern countries,
that were migrating up into the world's atmosphere,
were drifting around,
and were causing a thinning of this thing called the stratospheric ozone layer -
you've all likely heard of this challenge, right?
And so, as a young kid looking back,
I started to understand
that even the most seemingly abstract environmental challenges -
these things that seem kind of distant and apart from us -
end up affecting people and human populations
in really deep and profound ways.
Ultimately, I got into environmental stuff,
not for polar bears - although polar bears are awesome
and we should all love polar bears -
but I got engaged in environmental stuff because of people,
out of a deep concern
for what environmental degradation means for people.
It turns out that if you want to encourage human flourishing,
you need functioning ecosystems.
If we start to run down the capacities of ecosystems to sustain life,
then human beings suffer.
And so that's part of what drew me to environmental matters.
And another part of this was a deep sense of optimism
about the ability of human beings to come together in meaningful ways
to address and attack big concerns.
If you think about ozone depletion again,
the world was able to come together through international agreements,
through other mechanisms,
to do something meaningful about the challenge of ozone depletion.
That has not been the case with climate change.
Climate change is, by many measures, the biggest challenge that we now face.
Here in the United States though,
it's almost impossible
to talk meaningfully about a political response to this challenge.
We have known about the basic science of climate change since the late 1800s.
It was on the political agenda around the first Earth Day in 1970.
We're talking now a few days after celebration of Earth Day.
At that first Earth Day celebration in 1970 in the United States,
20 million people in the United States participated in Earth Day activities.
It's impossible to imagine that today,
that you'd get 20 million people out into the streets
coming together in community to talk about and respond to environmental concerns.
We've reached a point where the climate change conversation
seems more about theology than it does about science,
where you can believe in climate change
if you affiliated with one political leaning
and you're not supposed to believe in climate change
if you're affiliated with another political leaning.
That's a form of madness.
At the international level, things are just as tough.
International community, countries that are struggling to come together,
given competing interests,
prerogatives, needs for economic growth and so forth,
to come up with meaningful international forms of action.
So we're just not getting there on climate change.
Given that, it's no surprise
that we've got a larger growing chorus of voices calling for a plan B.
If we can't get there
with political responses, with social responses,
maybe what we need are technological responses,
large-scale technological interventions
that might make this problem go away or at the least will buy us time.
Now this is going to get technical for a moment,
but you need to understand what's being talked about
so you can understand what's going on in the conversation.
So when people talk about climate geoengineering technologies,
they typically talk about two broad categories.
On the one hand, we have one known as carbon dioxide removal technologies.
Now these are any of a growing number of possible options
that might be used to bring carbon out of the atmosphere
and hold it in long-term benign storage or make it useful.
And so an example would be, as I mentioned earlier,
putting iron into the oceans to cause blooms of phytoplankton.
Now the challenges with these sorts of approaches on the technical side
are myriad.
Most of these options being imagined -
none of this is deployed at scale.
Most of these ideas that are being imagined
are very, very costly.
They only work over a very, very long time frame,
and they're very hard to deploy at scale -
it's hard to get enough of this going quickly enough
to really make a dent in the atmospheric carbon load.
All that aside, there are some very promising technologies in this category,
and there's some very interesting and innovative research going on
that might make a real dent
in how much carbon we have in the atmosphere.
Where there is more obvious promise for an immediate response
is with this other category, of solar radiation management.
Now solar radiation management technologies
are, like those sulfate particles in the stratosphere,
anything that would increase the reflectivity
of some part of Earth's systems
to reflect some amount of sunlight or solar radiation back into space.
Models suggest that if we could reduce the incoming solar radiation by about 2%,
we could reduce global average temperatures
back to pre-industrial levels.
So these technologies offer a kind of a hand on the thermostat;
we could turn down global average temperatures
by these sorts of large-scale technological manipulations.
And we have natural analogues
for some of the things that you see on the slide.
Sulfate particles are put into the stratosphere,
up into the upper atmosphere, when volcanoes erupt for instance,
And so when Mount Pinatubo, a volcano in the Philippines,
erupted in the early 1990s,
that volcanic eruption spewed something like 20 million tons of sulfur dioxide
into the atmosphere.
The global average temperature
cooled by about 0.5 degrees Celsius for many months.
I don't even know what that is in Fahrenheit.
At some point, the United States will catch up with the rest of the world
and adopt the metric system.
(Laughter)
Until that point comes -
So 0.5 degrees Celsius for some period of time.
Where were we?
(Laughter)
So we have this natural analogue for this sort of response.
We know that we could do this,
we could replicate what happens with volcanoes
using existing technologies relatively cheaply, relatively quickly,
and would make a pretty immediate dent
in one of the major challenges attached to climate change,
which is global atmospheric temperature increase.
So those are the upsides;
you can see why these sorts of technologies are so enticing.
You can see, given the political struggles that we're having
coming to grips with climate change,
why people might point to these sorts of options,
but as with any complex conversation, there are downsides.
Now I take very seriously the admonition of the physicist Freeman Dyson -
when it comes to talking about these sorts of concerns, about big technologies,
either to stand a post or to push them forward -
you are gambling with lives.
This ultimately, again, is a question about people.
And so it doesn't make any sense to me,
given that climate geoengineering is a big umbrella term
that covers lots of different possible options
that might be used in lots of different possible ways,
to say, "Yes, I'm for geoengineering," or "Yes, I'm opposed to it."
It's way too complicated for that.
What we need to do
is to take a hard-headed assessment of what these options offer us.
And so as I start thinking about the potential downsides
of these sorts of technologies,
I tend to think in three different categories,
three different kind of bundles of risks and challenges
attached to geoengineering moves.
The first of these categories of challenge or risks
are material risks, physical risks, in the world.
Now these are the sorts of risks
that most scientists looking at climate geoengineering
are currently paying attention to.
Just for simplicity's sake,
I'm going to talk just about solar radiation management -
remember what that is? -
so just this idea that we can reflect off incoming solar radiation.
And let's look particularly at the most common, talked-about idea
of putting sulfate particles into the stratosphere.
When Mount Pinatubo erupted -
this is a photograph of Mount Pinatubo erupting in the Philippines
in the early 1990s -
as well as cooling global average temperatures,
there's lots of good science
which suggests that the sulfate particles led to a disruption of monsoon rains
in the Asian subcontinent, affecting Bangladesh, India, Pakistan.
Now more than a billion people
depend on those monsoon rains for their drinking water,
depend on the availability of that rainfall for food production,
and so this idea that we might deploy sulfate particles even in a regional way,
say, over the United States,
in such a fashion
that it might disrupt rainfall and other weather and climatic patterns
in other parts of the world
is deeply, deeply troubling -
the climate system is complicated.
And another piece of this
is that we may not know if these are having the desired effect
unless they're deployed at scale for a very, very long time -
models tell us one thing,
but if this were to be done in the real world,
it might turn out to operate in a very different fashion.
We could not do this alone either.
This is not actually a response in and of itself to climate change,
because all it does is mask the problem.
As long as we were putting sulfate particles into the stratosphere,
the temperature might go down, but the carbon's still there.
And so if we ever stopped doing it,
if we ever turned off that stream of sulfate particles
into the stratosphere,
models suggest we would see a sudden spike in global average temperatures,
and that spike
would be much more destructive than a gradual increase in temperatures.
So all of these sorts of material risks and challenges
that scientists have been paying good attention to
tie to another set of challenges
they're only just now really starting to grapple with -
a set of political risks and challenges.
Can you name a human institution
that has survived for hundreds or perhaps thousands of years
and done the sort of complex things
we'd have to imagine human institutions could do to make this a reality?
How would we govern, domestically and internationally,
putting sulfate particles into the stratosphere
or some of these other geoengineering technologies that we're talking about?
It's very difficult to imagine,
and people are just starting to grapple with it.
Also attached to these political risks
are "Who gets to put their hand on the thermostat?
Who decides how these things are used?"
Because ultimately, there are big questions
about justice and control baked into this whole conversation.
Many of the scientific proponents -
the scientists who are pushing for geoengineering research and work -
seem to believe that if we opened up space using geoengineering
just to kind of buy us some time,
then the international community would get its act together -
suddenly we'd all come together
and we'd find a way to transition to a low-carbon economy,
which is the only way ultimately to tackle climate change.
But that to me just seems like magical thinking;
that doesn't make any sense to me.
If we can't get our act together in the face of looming crisis,
what makes anybody think
that we'd suddenly come together once the pressure's off.
It might be far more likely that in fact, this will be sold as a solution:
you can have your high carbon cake and you can eat it too,
you can keep living your life just as you're living it,
because we've made this problem miraculously disappear.
This is a real challenge that we can't shy away from.
And it relates to another kind of fluffier category
that I call existential risks,
and these are not existential risks
in the sense that our existence is threatened as a human species,
this is existential in the philosophical sense:
Who are we as human beings on the planet? What does it mean to be alive?
Because one way to think about these geoengineering technologies
is as an impulse to mastery of nature,
and lots of people say
this is the very impulse that got us into this mess in the first place.
So geoengineering could be used
as a way to prevent more effective actions on climate change,
for political reasons,
but also because they limit our social imaginations,
our ways to see other forms of response -
we might so buy in to the techno fix that we can't see another way forward.
I'm torn.
You can see why this stuff is complicated.
At the end of the day,
if sea level rise in Bangladesh
continues to become such a problem that lives and livelihoods are threatened,
it could be that the most just form of response
is to put a layer of sulfate particles into the air above the Arctic Circle
to try and prevent ice melt.
That could turn out to be the most just form of response.
But at the moment,
we're not talking about justice enough in this conversation,
we're not getting to the ethical and justice and political considerations
that need to be paid attention to.
This is no longer an abstract scientific conversation,
this has to more and more be a conversation
in the realm of politics, ethics, governance, and equity,
lest we be drawn down a path to a false solution.
At the moment,
[No false solutions]
lots of civil society organizations -
large green groups, social justice and human rights groups -
don't want to talk about geoengineering,
for fear of giving it unwanted legitimacy,
for fear that it will take us away from the other forms of response
that they would like to see happen,
but the message has to be "It's too late, we're beyond that now,"
with this conversation about these technologies.
The climate geoengineering genie
is far too enticing and far too powerful to be stuffed now back into its bottle.
We don't have that option anymore;
ignoring this conversation won't make it go away.
So what we need
are for concerned citizens - all of us -
and civil society organizations, who represent some of our interests,
to get more heavily involved in this conversation
to make sure that we move from "Is this possible?"
to "Is this desirable?"
Should we be doing this, and if we move down this path,
who benefits?
who controls it?
so whose ends and in whose interests
are these technologies being developed and potentially deployed?
My final message, my final line, is a straightforward one -
this is a meeting, this particular event, about the global future -
if you care about the global human future,
you need to start caring about climate geoengineering.
Thank you.
(Applause)