
It's Time to Start Talking About Geoengineering - benbreen
http://www.theatlantic.com/science/archive/2015/11/its-time-to-start-talking-about-geoengineering/414283/?single_page=true
======
kragen
[http://keith.seas.harvard.edu/papers/148.Holmes.Keith.Contac...](http://keith.seas.harvard.edu/papers/148.Holmes.Keith.ContactorForLargeScaleCapture.e.pdf)
is probably the most advanced current geoengineering proposal currently; the
estimated cost is US$60 per tonne of CO₂ removed, proposing to spend C$140M to
construct a facility that removes 1 megatonne of CO₂ per year. (One of the
authors constructed a small-scale prototype a few years earlier.) If this is
correct, a facility to remove all of the 29 billion tonnes of CO₂ emitted by
human activities annually would cost C$4 trillion to build (about one month of
global GDP) and cost US$1.7 trillion per year to operate (about 5% of global
GDP, comparable to the total amount currently being spent on energy.)

That is, unless Keith's analysis is wrong, low-risk geoengineering to
completely remediate current CO₂ emissions is clearly economically feasible,
but not as a skunkworks project — it's a project of a size comparable to the
entire existing energy industry, so it would need to be supported by the full
influence of the current Establishment. It clearly cannot be done as a market-
driven project.

These costs, already somewhat pessimistic, should come down a bit as energy
becomes cheaper with the proliferation of photovoltaic farms. Indeed, much of
the operating cost is the energy used, which would _have_ to come from non-
carbon-burning sources.

Many of the other geoengineering approaches mentioned — cloud doping, ocean
fertilization, stratospheric acid, space mirrors — would probably be cheaper.
Unless they crash the Earth's climate system!

~~~
yummyfajitas
The cheaper geoengineering proposal is emission of sulfur particles into the
stratosphere - i.e., the sunlight reflecting portion of a volcano. I don't
recall the cost estimates, but they were drastically lower than $4T.

~~~
kragen
You mean sulfate — the sulfur in the volcano oxidizes when it hits air at lava
temperatures, if it wasn't oxidized already. That's what I was referring to
with "stratospheric acid". It's true that it would be cheaper, but we're
talking about the equivalent of one Krakatoa eruption every couple of years,
for centuries. Nothing like that has happened since the advent of life on
earth, so although it might work and be safe, or it might have unexpected and
undesired effects, for example due to sulfuric acid in rain.

------
shoo
I listened to a talk by Clive Hamilton and Tim Flannery a few months ago,
where they discussed geoengineering.

I liked Flannery's framing of geo-engineering. I'm probably slightly
misrepresenting what he said, but it was something like this:

1\. we need to be seriously pushing a transition to a decarbonised economy,
i.e., actually reducing greenhouse gas emissions, before we start playing
accounting games with negative emissions

2\. then, as a secondary concern, at the same time as we're reducing our
emissions, we also need to be pursuing geo-engineering options to remove
carbon from the atmosphere

3\. there are many different kinds of geoengineering options. some of these
are more likely to strengthen or enhance existing earth systems, and other
approaches will damage earth systems.

I am glad to see Morton agrees with point #2:

> I'm very keen to get across in this book is that I do not in any way see
> geoengineering as an alternative to a program of emissions reduction. I
> think that that would be a very foolish approach to the problem.

There is a very big risk that geo-engineering is perceived as a magical patch
that will fix the problem - it can't fix the problem, but perhaps it can
alleviate some of the symptoms. Any particular geo-engineering approach will
have secondary implications (perhaps unanticipated, like the whole global
warming thing).

It isn't realistic to think that we can completely reverse the changes we've
set in motion - no reverse, only forward, into new and interesting (and
potentially non-adaptable) conditions we haven't yet experienced as a species.

------
willholloway
We are already removing carbon from the atmosphere at industrial scale,
550,000 tonnes per year with bio-energy with carbon capture and storage [1].

We can get a lot better at this, with engineered simple organisms like algae
growing fuel to be consumed and the carbon captured.

“If humanity wishes to preserve a planet similar to that on which civilization
developed and to which life on Earth is adapted, paleoclimate evidence and
ongoing climate change suggest that CO2 will need to be reduced from [current
levels] to at most 350 ppm.”

Dr. James Hansen

Right now we are at 398 ppm, and we are already seeing weird climate effects,
more, bigger wild fires etc.. I don't think the modern, developed world will
tolerate 450 ppm. Things will get too weird.

I think we will be forced to capture carbon.

> a facility to remove all of the 29 billion tonnes of CO₂ emitted by human
> activities annually would cost C$4 trillion to build

We will get these costs down, but to me, even 4 trillion looks downright
affordable, the US spent that much invading and occupying Iraq.

[1] [https://en.wikipedia.org/wiki/Bio-
energy_with_carbon_capture...](https://en.wikipedia.org/wiki/Bio-
energy_with_carbon_capture_and_storage)

------
mirimir
> The atmosphere is becoming a greenhouse. The surface of our planet is now
> warming, with unpredictable consequences.

Our planet would be frozen solid if it weren't a greenhouse ;)

~~~
Ygg2
I heavily suspect that is the case. Our climate depends on more than just sun
patterns.

Historical record show Golf current supplies heat to Europe. Once that fails
instant ice age tends to start. With increased temperature, ice cap melt and
salinity of water drops, which causes Golf current to stop.

------
groutexpectatio
geoengineering as a concept operates with a High Modernist ideology, and
overwhelming confidence in humanity's ability to reshape the natural world,
society, the State, in a desired fashion. i think relying on policy and
markets and the state makes sense public works cleanups, removing tax breaks
and subsidies for industries that produce externalities, restructuring labor
into environmentally-minded industries and sectors....but i'm ultimately
skeptical of a technological fix, sprinkling oceans with lead or growing mass
plankton farms or whatnot. sounds like snake oil to me.

------
userulluipeste
Why not calling it "planetary engineering" from very beginning? The experience
gained in here will not be limited to Earth!

Also, I think that the ambition of changing the atmospheric composition can be
a little bit higher. The talk now is (only) about the removal of CO₂ from the
atmosphere (releasing back the oxygen, I guess), but an increase in the
atmospheric proportion of oxygen, from sources other than carbon dioxide,
would be beneficial too (at least for humans, as the blood thickness would
drop and so would do a lot of the cardiac related issues). Currently there is
a great deal of oxygen trapped in different kinds of oxides (SiO₂ especially)
that would to us more good in the atmosphere.

------
iwwr
There's more to geoengineering than just aerosols. Ultimately, it'll be about
giant mirrors and barriers in space to modulate the Sun's radiation in various
places. It may sound fantastic, since these are huge surfaces involved, but
you can block or reflect the Sun's light with very thin materials, which can
be folded up on their way up.

------
Lionleaf
The reason geoengineering scares me:
[https://xkcd.com/349/](https://xkcd.com/349/)

~~~
shoo
if it makes you feel any better, the status quo is implicitly geoengineering
the planet in a particularly stupid way.

~~~
Ygg2
So instead of stop doing the stupid things, we should instead do another
stupid thing. Hoping that stupid cancels itself?

