Running the numbers on an insane scheme to save Antarctic ice | Hacker News Reader

Running the numbers on an insane scheme to save Antarctic ice

arstechnica.com

103 pointsjseliger34 comments

A few years ago I did some back-of-the-envelope calculations regarding sulfur dioxide injection into the stratosphere: http://curtisb.posthaven.com/someday-soon-chemtrails-may-be-....

The proposal for saving Antarctic ice in the submitted article may be just too big for humans to do. Sulfur dioxide injection, however, is dirt cheap, and we could definitely do that. I'm not saying it's a good idea, but we can do it.

It's so cheap that a nation threatened by climate change likely will do it "rogue", without international consensus. It's less a matter of "if" but "when."

You do know that sulphur dioxide in the atmosphere causes acid rain, right?

This paper considers that very question: https://agupubs.onlinelibrary.wiley.com/doi/pdf/10.1029/2009...

From the "Conclusions" section:

> Analysis of our results and comparison to the results of Kuylenstierna et al.[2001] and Skeffington[2006] lead to the conclusion that the additional sulfate deposition that would result from geoengineering will not be sufficient to negatively impact most ecosystems, even under the assumption that all deposited sulfate will be in the form of sulfuric acid. However, although these model results are feasible, should geoengineering with sulfate aerosols actually be conducted, local results due to weather variability may differ from the results presented here. With the exception of terrestrial waterways, every region has a critical loading value a full order of magnitude above the largest potential total amount of acid deposition that would occur under the geoengineering scenarios presented in this paper. Furthermore, our results show that additional sulfate deposition tends to preferentially occur over oceans, meaning the chance of such a sensitive ecosystem receiving enough additional sulfate deposition to suffer negative consequences is very small.

Also note that I did not say that sulfur dioxide injection was a good idea, only that we could afford to do it.

At the very least it would provide incontrovertible evidence that humans can effect the climate. As if there wasn't enough evidence already :(

The 1991 eruption of Mt Pinatubo caused 0.5C degree of cooling the following year (i.e. instantaneously).

We need short-term remediation, starting immediately. This is the only cost-effective method.

https://pubs.usgs.gov/pinatubo/self/

Iron fertilization seems like a much more reasonable approach:

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

Each kilogram of iron can fix 83000 kg of carbon dioxide and turn it into biomass.

How much of that is permanently fixed, and how much of it goes right back when those organisms die?

Bury it deep? A large part of the carbon should remain and turn into coal.

From linked article:

"Of the carbon-rich biomass generated by plankton blooms, half (or more) is generally consumed by grazing organisms (zooplankton, krill, small fish, etc.) but 20 to 30% sinks below 200 meters (660 ft) into the colder water strata below the thermocline. Much of this fixed carbon continues into the abyss, but a substantial percentage is redissolved and remineralized. At this depth, however, this carbon is now suspended in deep currents and effectively isolated from the atmosphere for centuries. (The surface to benthic cycling time for the ocean is approximately 4,000 years.)"

Sounds insurmountable. That said, in the context of the 50th anniversary of Apollo 11, this feels like there are far more knowns than unknowns.

Think of it this way. JFK laid out a challenge that in retrospect amounted to "Here's a iPhone. Go put us on the moon. Soon!"

THAT was madness. Redistribution of some water* - even at this scale - is more Mercury than Apollo. It seems it might be us who now knows too much to be crazy enough to try. That's a shame.

* On a daily basis we redistribute a massive amount of oil. So there is a reference point in terms of volume / scale.

The are talking about moving over 100x times as much water per year as we move oil. Further, it’s only going to freeze during winter adding even more time constraints.

Just desalination of this much water would cost ~5 trillion dollars in the US. Doing this in the Antarctic winter would probably double that if not more.

"The are talking about moving over 100x times as much water per year as we move oil." > Fair enough. But 100x still isn't a moon shot.

"Just desalination of this much water would cost ~5 trillion dollars in the US." > Perhaps. But what is the cost of NOT doing it? 2x? 3x? 5x? 10x?

Long to short. if it were easy we would have done it already. Therefore, I have to believe the next steps are going to be hard, harder, and perhaps hardest (i.e., greater than going to the moon on the back of an iPhone).

The only impact of not doing this is less sea level rise. The ocean is still going to rise significantly, thus the savings is likely less than the 10++ trillion this would cost.

Remember, this is also not a long term solution, it would need to be repeated over time.

How do you figure that not doing this would cause less sea level rise? The article states that proceeding with this plan might slow sea level rise to nearly one-third of its current rate:

> To put that into context, removing that much seawater from the ocean would lower global sea level by about 2 millimeters per year. Current total sea level rise is a little over 3 millimeters per year, so it would be like nearly halting sea level rise… by bailing water out of the ocean. We can call that a bonus positive.

On what grounds do you dispute this? I'm not saying you're wrong (I'm too uneducated in the relevant fields to know that), I'd just like to know your rationale?

Poor use of double negative.

I mean you are not going actually fix global temperate, weather patterns, ocean acidification etc. It’s benefits are simply going to be limited to stuff very near the ocean, and when you start talking trillions of dollars that builds a lot of structures.

https://advances.sciencemag.org/content/5/7/eaaw4132 - original article

https://en.wikipedia.org/wiki/Sverdrup - unit of flow for ocean currents

145GW of power needed to raise water up 640m. Desalination not included, may be necessary. Would require 12k high-end wind turbines given local wind conditions. This is around 25% of current global wind capacity.

https://wwindea.org/information-2/information/ - "UPDATED: 4 June 2019 Wind Power Capacity Worldwide Reaches 597 GW, 50,1 GW added in 2018 China with more than 200 GW, USA close to 100 GW, Europe in decline Bonn, 25 February 2019 (WWEA) – The overall capacity of all wind turbines installed worldwide by the end of 2018 reached 597 Gigawatt"

Does 12000 windmills sound like a lot? Consider that we have 1.7 million oil wells in the USA alone.

When you consider that's 12,000 for the least energy intensive part, just pumping the water, yes. A hell of a lot.

How many extra windmills for desalination and freezing to produce snow? How many acres or square miles of desalination plant? How to dispose of the few(!) tonnes of salt? How much of the world's shipping, construction and engineering requires commandeering, WW2 style to ensure it's a ten year not fifty year project?

Many recent discussions around the unfolding global warming catastrophe have asked, "What can we do?" Besides the obvious, Climeworks now has a scheme to let average people pay to bury carbon: https://www.climeworks.com/. I've signed up but have no information beyond the articles I've read about the company: https://www.nytimes.com/2019/02/12/magazine/climeworks-busin....

It seems we're past the point where reducing emissions will be enough, and to the point where we need to reverse atmospheric CO2, now.

I agree, I think geoengineering is unavoidable. As far as geoengineering projects go, this one looks like the most feasible and safe so far:

https://projectvesta.org/

Could you elaborate? Enhanced Weathering is questionable on many levels. Have you compared it to other approaches?

Why is enhanced weathering questionable? I don't really know much about it, but I was under the impression that carbon absorption by weathered silicates will have a dramatic impact on the planet over the very long term[1]. Is enhanced weathering just too slow, or is there more to it than that?

[1]: https://en.wikipedia.org/wiki/Future_of_Earth

I've only compared it to sulphur dioxide and the risks look fewer. The other benefit of enhanced weathering with olivine distributed in energetic waters is that it removes CO2 from the ocean (letting the ocean act as a carbon sink for the atmosphere).

I'm interested in learning more about research into enhanced weathering, could you provide some recommendations?

I‘ve come to the conclusion that planting trees is probably the best strategy in the short term. While there‘s obviously limited space to continue that forever without advanced strategies such as BECCS, it’s a super safe and extremely scalable option (drones!) with lots of other benefits that would give us a massive head start for the next 10-20 years until we figure out how to scale CO2 capture.

I agree we should also plant trees and cultivate forests however that won't help fix our oceans.

The reason why I like the olivine weathering proposal is that it weathers co2 out of the ocean and uses the ocean as a carbon sink. This way you remove co2 from the both the atmosphere and ocean (if you weather enough of it).

Thanks for sharing this, I wonder why more projects like this aren't under way already?

Sounds like the time to seriously start to consider these kinds of projects is now.

Climate change catastrophe has been exaggerated for over 30 yr now

UN predicted catastrophe in 1989

https://www.apnews.com/bd45c372caf118ec99964ea547880cd0

The IPCC predictions tend to be too conservative:

https://www.scientificamerican.com/article/climate-science-p...

https://www.vice.com/en_us/article/43e8yp/the-uns-devastatin...

It's just that "catastrophic" changes meaning over time. Permafrost melting on a massive scale? Catastrophic prediction thirty years ago, just another item in the news today. Losing almost all coral reefs? Today it's just something we can't prevent anymore.

Given our disastrous track record with any sort of environmental engineering, I don't think this is a good pandora's box to open.

Also, any plausible form of geoengineering still requires carbon emissions to be reduced to 0 as soon as possible. Since that is known to be within our technical capacities, and known to be safe, it still seems like the first step that we must dedicate our energies to.

As long as our CO2 emissions still grow every year, it's much more cost effective to work on that rather than remove some tiny part of it afterwards.

How about using planks of cooling wood[0] to cover parts of the sea instead?

It should float and perhaps can create a cooling effect large enough to make ice out of already freezing seawater?

[0] https://www.coolingpost.com/features/cool-wood-could-take-th...

Reply on news.ycombinator.com