A subpolar-focused stratospheric aerosol injection deployment scenario | Hacker News Reader

A subpolar-focused stratospheric aerosol injection deployment scenario

iopscience.iop.org

53 pointsrntn46 comments

- "6.7 Tg-SO2/yr in each hemisphere"

Perspective: that's roughly one Berlin airlift in each hemisphere. (Peak airlift was 12,941 tons/day, which would be 4.7 million tons annualized).

https://en.wikipedia.org/wiki/Berlin_Blockade

I don't know if the approach in the OP is a correct one or not; but it would embarrass the history of our species to argue we're not capable of doing it.

What's interesting to me is that there's nothing stopping one country from deciding to do it. Canada, USA, Russia, even Denmark (via Greenland), Finland, Norway, Sweden or any nation near the south pole.

It's a logistics problem, not a technology problem.

Just as there's no legal framework to force countries to not make the climate warmer, the same goes for cooling the climate.

This idea is explored in Neal Stephenson's Termination Shock. There was no stopping one crazy billionaire, let alone an entire nation.

https://en.wikipedia.org/wiki/Termination_Shock_(novel)

Also, access to international sulfur markets.

That wouldn't be a barrier for Canada though, which has access to an unlimited supply from (ironically) its oil industry. Athabasca oil sands are somewhere around 5% sulfur, most of which gets extracted and piled up into useless pyramids (since no one is buying it).

https://www.businessinsider.com/there-are-mountains-of-sulfu...

https://boingboing.net/2016/07/05/the-great-sulphur-pyramids...

Perfect. At long last my country will take it's rightful place as ruler of the world: we'll start a massive global cooling project and threaten to end it in a termination shock if we aren't properly compensated for it.

Neil Stephenson explores this theme in Termination Shock [1], worth a read if you are curious about the subject.

[1] https://en.wikipedia.org/wiki/Termination_Shock_(novel)

I'd want there to be a 0% chance of unintended consequences before taking this seriously. And even then when there is no other choice.

Don’t stand in the way of their hubris.

How DARE they try to prevent the extinction of the human race!

dude stop pretending like global warming will cause our extinction or provide a source to back it up. none of the models i've read supported any conclusion like that

But CNN told me.

https://www.nature.com/articles/d41586-019-03595-0

you can live in your own wishful thinking fairy tale where models make "conclusions" but over here in reality we have to live knowing that extinction is a possibility because veering away from equilibrium means you cannot predict in the first place.

your article doesn't say anything about human extinction. it talks about a "tipping point" in climate change but has no evidence to suggest human extinction. provide a source or stop claiming it will make us extinct.

Why are humans the only creatures that matter? Are we the only ones capable of suffering? If it wipes out a quarter of all species isn't that a catastrophe, even without considering our dependence on them? Myopia like yours is how humanity got here.

i didnt say that. i was responding to a hyperbolic and utterly baseless claim that climate change wpuld cause humanity to be extinct. it's an absolutely cnn-tier nonsense statement.

It's hyperbolic but there is value in its core - ecosystem collapse would bring us close. And the point below is not unreasonable - our collective response to 1.5 vs 4.5 degrees warming will not be linear. Mass migration, resulting fascism, resource wars and mismanagement, evaporation and starvation could finish those who remain.

If we're forced to live a completely different lifestyle it may be tantamount to the extinction of modern humanity.

Have you met humans? Even if climate change itself does not bring about extinction, there's a very real possibility that human stupidity in response to climate change (and other related factors) could very well start a chain of events that realistically might end with an extinction level event of one kind or another. Hell, even without climate change aggravating things, some lunatic like Putin could start something we'd all regret…

0% chance of side effects is unrealistic. A better way to think of it is like the hippocratic oath that doctors adhere to: to do no harm.

Yet just a few weeks ago a doctor cut some holes in me. That’s clearly harmful, yet in the balance I was quite glad he did so sad that way he could repair my arm. So a trade off analysis is required.

Fortunately there’s a emerging governance, e.g. from the Climate Restoration Safety and Governance Board that’s just starting up. It already has a pipeline of projects waiting to apply for regulation.

We perform operations all the time. The consequences are generally well known.

An operation on your body has consequences for you alone. You can consent to it. We won't find consensus on altering entire climates.

Or instead we should only do interventions that are easy to undo (or stop)

Wait, even with a 0% chance of unintended consequences, you’d still insist on exhausting literally every other option?

These climate doomsayers are really committed to the bit.

As opposed to the 100% chance of massive, civilization threatening consequences if we do nothing?

The contrast is illuminating.

We already know what to do.

The question of whether or not this type of intervention will be necessary comes down to the specifics of various climate tipping points.

There's evidence that we've already crossed a tipping point with regards to methane release (https://www.nature.com/articles/s41467-022-28989-z). The loss of arctic sea ice is another important one, as the albedo of the earth decreases as the reflective ice turns into water.

It seems likely to me that some amount of solar geoengineering will be needed to bridge the gap from now until we achieve a carbon drawdown.

I might have missed it, but they don’t seem to talk about the fate and transport of the sulphuric acid that forms when the sulfur dioxide oxidizes. This is important to know.

I find "marine cloud brightening" [0] a lot more interesting. It aims to increase the albedo of Earth by creating more clouds over the oceans e.g. by spraying seawater.

Pro: "If implemented, the cooling effect is expected to be felt rapidly and to be reversible on fairly short time scales.", [0]

[0] https://en.wikipedia.org/wiki/Marine_cloud_brightening

> It aims to increase the albedo of Earth by creating more clouds over the oceans e.g. by spraying seawater.

Sort of; what we're usually doing, in general, is increase the aerosol burden which in turn increases the total number of nuclei available to form clouds. Given that the total liquid water content in a cloud system is fixed (i.e. controlled by factors that are harder for us to influence directly), this leads to a mixture of consequences:

1. The total number of cloud droplets increases 2. The average cloud droplet size decreases

Both (1) and (2) alone tend to increase the albedo of the cloud. They also produce secondary effects, e.g. they can suppress the formation of precipitation or modify microphysical properties that lead to clouds sticking around longer, thereby further increasing their radiative effect (more SW radiation reflected back to space and possibly more LW radiation at lower radiating heights).

We can guess by looking at the SO₂ deposited by volcanic eruptions

> [The 1991 eruption of Mount Pinatubo released] 17 megatons of sulfur dioxide into the atmosphere, causing global cooling by 0.5 °C (0.9 °F) between 1991–1993

> [It] oxidized in the atmosphere to produce a haze of sulfuric acid droplets, which gradually spread throughout the stratosphere over the year following the eruption

https://en.wikipedia.org/wiki/1991_eruption_of_Mount_Pinatub...

The vital difference is that vulcanic eruptions are basically a pulse-chase 'experiment', whereas geoengineering would require sustained injections with smaller doses.

The argument usually raised is that the volume is too small to matter (and a comparison to SO2 volcanic eruptions). I haven’t seen those studies so am at the moment dubious (but would like to be wrong).

I'd be easier to just nuke a caldera.

I know. I know! But where's the lie, we have a lot of them.

Does anyone have good sources on effects that this kind of intervention would have on solar power?

I haven't seen it discussed before so maybe it's negligible, but I'm curious.

Fun fact: we are currently in an ice age. By definition, when ever there is ice sheets covering both poles we are in one.

The default state for earth is no ice over the poles (as far as we can tell)

The amount of ice also fluctuates wildly in an ice age. The ice coverage can be where it’s currently at (poles), all the way to an ice sheet covering half of the US and Europe.

But in the last 5 million years, there’s a cycle where ice sheet size and thickness increases, then decreases at a regular 100k interval. The last few thousand years we’ve been at a lower and decreasing end of ice

https://en.m.wikipedia.org/wiki/Ice_age

The idea that we’d want to put the Earth back into an ice age when (1) that doesn’t appear to be the default for earth and (2) an ice age means less food — it’s an insane idea.

Scarier that any random old country could probably do this without consent of the globe.

An ice age also means more arable land, and eventually megafauna. Downside: Everyone has to move into former ocean plains Upside: You will be able to walk to circumnavigate most of the planet

Earth at glacical maximum https://www.cbc.ca/greathumanodyssey/content/assets/images/m...

Nowhere in the "Expected climate impacts" section is inducing an ice age even on the table. The anticipated effect is a 2C cooling of the atmosphere. Considering we're on track to blow way past a 2C increase in atmospheric temperature from 100 years ago to 30 years from now, SAI would be a mitigating action. The goal is to maintain our habitat.

"Expected" - is the keyword here. No one should (and I belive will) agree for any kind of "geo-climate-engineering experiments" unless our science is actually capable of predicting/simulating exactly what's going to happen. Said understanding of the climate and ability can be proven by let's say consistently successful weather forecasts for 14 days in advance. Then we can talk.

Until then, even seriously considering it is stupidity of the worst kind exemplified by results of smaller attempts to "engineer" things we don't understand fully such as destruction of the Aral Sea and its ecosystem and many others.

"But, but, we _already_ "engineer" our climate by releasing large amounts of greenhouse gases!" say proponents of such ideas. To which I say, those things cannot be compared. During the earth's history there were many significant releases of co2 and methane we can study (from mega volcanoes, to asteroid impacts caused planet wide forest fires). There were times when the earth's atmosphere had 10 times the co2 it has now and it didn't cause a Venus-like runaway greenhouse effect some people are so keen on presenting as an almost certain scenario. The planet managed to reabsorb it.

We can mitigate many effects of climate change that manifests itself as few degrees of warming (including all the more intense weather events) much better than let's say a significant drop in temperature for a decade.

In 50 years we will think about such climate-engineering ideas the same we now think about ideas from 1950s to use nuclear explosions for building canals, and other "soil moving" ideas. Insanity.

> Said understanding of the climate and ability can be proven by let's say consistently successful weather forecasts for 14 days in advance. Then we can talk.

Weather prediction and understanding the impacts of SAI are two very completely different problems. This is an arbitrary and not particularly relevant benchmark for gating geo-engineering work.

That being said there are many, many ethical, political and other technical reasons why geo-engineering is a very bad idea and should be avoided at all costs. Undoubtedly, mitigating as much as climate change from occurring by quickly reducing global GHG emissions should be one of the main laser-focused areas of everyone involved in stopping climate change.

Here's the problem: homo sapiens didn't evolve during a period when both poles were ice-free.

Reminds me of the Snow Piercer movie/series:

https://en.wikipedia.org/wiki/Snow_Piercer

Let’s hope Elon Musk won’t start building a mega train.

I would expect the train to be built by the child with a heart of gold that inherits Musk's estate.

https://youtu.be/jEX52h1TvuA

Like volcanos

The dumbest idea ever thought of.

Second dumbest at most.

The dumbest idea is blowing CO2 that was sequestered during millions of years into the atmosphere within a couple of decades.

Where does the plan to continue to do it for decades fit in?

That would change the original comment to THIRD dumbest.

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