(upbeat music)
- People are starting to realize
that if we can't find a way
to pull carbon out of the atmosphere quickly enough,
then solar geoengineering would be the only option
in the fight against climate change.
This is possibly the first technology
that would be truly global and that whoever chose to use it
would be affecting everyone else on the planet.
- This is not a technology that people want to use.
The number one thing we need to do
if we are really to address climate change
is to reduce emissions.
But I think to try to keep it in a lockbox, that's not fair.
Solar geoengineering is a global issue
and people have the right to understand it and weigh in.
- In the UN climate talks in Paris,
the world agreed to try to keep warming below two Celsius
above the pre-industrial level.
But as things stand we are emitting CO2 so quickly,
we're heading towards more than three Celsius of warming.
And that's if every nation makes every promise
that they made in Paris.
We know we've got to cut emissions
as fast as we possibly can.
But just cutting emissions might not be enough.
- Solar Geoengineering refers to the idea
that you could reflect a very small fraction
of sunlight back into space to offset some but not all
of the impacts of climate change.
We know if we reflect sunlight back to space,
we will cool global average temperatures.
We see this in a lot of natural examples,
including when volcanoes erupt.
- So the leading idea for doing solar geoengineering
is spraying millions of tons of slightly reflective
aerosol particles into the upper atmosphere.
- We start with laboratory experiments,
where we try to replicate the stratosphere.
But you can never be 100% sure that your lab system,
this little tube in the lab reflects the entire complexity
of what you're looking at in the earth system.
So we have to test them in the real world.
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The goal of SCoPEx is to better understand
the impact of putting calcium carbonate
into the stratosphere.
- SCoPEx is a very small scale experiment.
It would pose no physical harms
in terms of its potential impacts on humans or ecosystem.
The idea is, we would take a stratospheric balloon
that would release a very, very small amount
of calcium carbonate, less than two kilograms.
This plume of particles creates an outdoor test tube,
if you will.
Then the balloon will turn around and zigzag
back through those particles, taking samples,
trying to understand how are these particles dispersing?
How are they reacting with other particles
in the stratosphere?
We'll come back down to the ground
and the scientists will analyze those results.
- There's a risk in doing this research.
There is some aspect of giving this idea legitimacy.
My concern is that humanity may maneuver itself
into a situation where suddenly people decide,
well, the only thing left we have to do is geoengineering.
I think there's needs to be some research
to get a better understanding of what the risks are.
Because this decision will be made,
whether we have done research on it or not.
- One of the most serious potential risks
of solar geoengineering is termination shock.
If we were to use solar geoengineering
to suppress global temperatures,
but we didn't do anything about CO2 emissions,
and if for some reason you were to stop suddenly,
all of the solar geoengineering,
then those temperatures would suddenly spike back up.
And that would mean that human and natural systems
had less time to adapt to the new conditions.
- Fundamentally, the earth system
is a highly complex system.
- The questions become, what does it do
to the other climate variables that we care about?
That's why we need research.
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So the question today is not about deployment,
it's about research.
We cannot do research and try to lock solar geoengineering
in a box or we can start doing the research now
to better understand the potential benefits
and the potential risk.
- We have a great responsibility for all those people
who haven't contributed to climate change,
but will have to pay for it, including our future generations.
- Solar geoengineering would involve
deliberately intervening in the entire
planet's climate system.
Who gets to make that decision?
Is this going to be a decision that's based on evidence
or based on emotion?
How do we make sure that the most climate-vulnerable
countries of the global south are heard?
I hope that we will find our way out of the climate crisis
by cutting emissions and through adaptation.
Solar geoengineering could be really helpful
in the fight against climate change.
At this stage, we just need to understand it better.
(soft music)
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