Hacker News new | ask | show | jobs
by BillFranklin 970 days ago
Yeah it's mentioned in Stephen Hawking's last book: https://en.m.wikipedia.org/wiki/Stratospheric_aerosol_inject...

“The Intergovernmental Panel on Climate Change concludes that it is the most-researched solar geoengineering method, with high agreement that it could limit warming to below 1.5 °C”

There’s a risk it’d affect the ozone layer. But Paul Crutzen, who won the Nobel Prize for his ozone research in 95, said the sulfur plan is “the only option available to rapidly reduce temp rises and counteract other climactic effects”.

We’d also need to add shockingly little SO2 to the stratosphere. We currently emit 200m tons per year (25% is humans, rest is volcanos and other natural sources). We’d need to add an extra 100k per year.

Edit: I think one of the Microsoft co-founders was looking into it, the problems of proving it would work were political - not engineering-related.

3 comments

It always strikes me as odd that the geoengineering experiment that got us into the predicament (dumping boatloads of CO2 into the atmosphere), the politics were so much easier.
I've generally come to the belief that it's related to how humans think about cause and effect.

Dumping boatloads of CO2 into the atmosphere is second order from the actual goal of producing electricity so most people just can't/don't/won't think about it.

In this case we'd be intentionally dumping SO2 so people are capable of thinking "wow that's not moral" or whatever issue they might have with it.

I think the biggest concern with something like releasing SO2 as a geoengineering project, which needs, quoting someone else in the thread "very little" to be released to have a big effect, the concern is over-correction or unforeseen effects caused by an insufficient understanding of the system as a whole.

Don't want to accidentally start an ice age by trying to prevent a hothouse planet from forming :P

And we want to stop releasing CO2. We don't want to wind up charging onwards to 1,000 ppm CO2 just because we released enough SO2 to compensate for the climate change.
Especially since human brains suffer significant cognitive effects above 1,000ppm.
Sounds like a self correcting problem to me. At what ppm levels are humans too stupid to support an industrial civilization? Full speed ahead...
"SnowPiercer" here we come...
The current predicament we are in was not produced by a deliberate attempt at global geoengineering. It was a global economic project with a byproduct of climate change.
It does not matter if someone screwed up my life on purpose or by accident, I am still harmed
I'd say that we need to discover a source of energy that produces SO2 as a byproduct, but given our species' track record we would probably trigger an ice-age in a few decades.
Hah!

Or maybe if some billionaire could figure out a way for their space-tourism project to “accidentally” produce SO2, then we’d give them the moral mulligan.

SO₂ was a byproduct of coal power stations, we started scrubbing it because it was the cause of acid rain.
100k or 100M?

200M + 100k = 200.1M, and I doubt the 200M figure had 4 significant figures.

It'd be a smaller amount that gets injected into the stratosphere, as opposed to what we normally release into the troposphere. A quick skim of the wikipedia link seems to suggest 5M tons in total, not sure what the annualized basis would be.
That's a tiny amount, relatively. But is that "just a little more" or is it "just a little more, but in a really inconvenient and difficult to reach altitude"?

What kind of infrastructure would be required to put it where it needs to go?

You would need a few pipes the width of garden hoses constantly flowing, suspended by helium balloons, near the Arctic where the stratosphere is 1km closer.
I think putting any amount of tons of matter into stratospheric altitude is a hard challenge.

Especially if we consider the fact that you would be putting upwards of 200t[0] of CO2 into roughly the same altitude Only to deliver maybe 5 tons of sulfur.

[0]: https://www.theguardian.com/science/2021/jul/19/billionaires...

But we don't need to do that excessively fast. How about a stratospheric balloon? Balloons reach 30-40 km for weather observation purposes.