Can artificially altered clouds save the Great Barrier Reef? | Hacker News Reader

Can artificially altered clouds save the Great Barrier Reef?

nature.com

32 pointsdr_dshiv47 comments

My son is working on a school essay about cloud brightening and the great barrier reef. He is trying to understand why there is so much opposition to doing this research.

Any hints or reasoned arguments to share?

I guess fuckups are potentially very bad and very hard to contain. Could be long-lived too.

I would say that there is a lot of interest in some quarters for this sort of solution, as it might mean that we could save the GBR without curtailing the energy industry. I think resistance to these ideas might be related to dealing with the symptoms; high ocean temperatures, rather than the causes; human-induced climate change. I support science-based evaluation of all these ideas, but without ignoring or addressing potential causes.

This makes sense. But surely they understand that, even if Australia went carbon neutral tomorrow, it would not be enough to cool the reef waters?

Yeah sure, there is too much momentum in current climate changes for Australian policy to turn it around. But the argument that Australian emissions are tiny in comparison to US, India or China so we don't need to be a part of the global solution falls flat for me. If we can punch above our weight in trade or diplomatic spheres, surely we can do the same in climate-mitigation areas.

Where do you see resistance to these mitigation attempts like cloud brightening?

That would deprive him from the joy of finding the answer by himself. Learning critical thinking is a valuable skill for any child and this case is an easy example to try his wings in this sense.

Humans are a cooperative species. Seeking help and wisdom is part of the process. Nothing is being taken away or deprived here, and from what i can tell that's a hell of an overreach on such little context, unless you've caught something I missed?

Hard disagree. The suggestion that you should find an answer all by yourself through just thinking is a primer for unchallenged speculations.

Asking someone is the very prerequisite to develop your ideas. Looking at data is an asynchronous way of asking someone. There is no critical thinking without exchange.

Maybe my comment in this thread can encourage him to take the calculation further, like trying to find out how many Wh are needed based on physics alone to accelerate the requisite mass of water needed on a daily basis, which gives you a lower bound of how much electricity / fossil fuel / m³ of hydrogen / percentage of nuclear power plant output is needed for that.

I think my unfinished back-of-the-envelope calculation strongly hints at this plan being not practical. Another factor to consider is the large scale impacts and assessment of the sheer predictability of outcomes for the ecosphere and for society alike. To me it looks a lot like some people just don't get that messing with the environment on a global scale is qualitatively different from, say, watering your 300m² garden or turning that knob on the radio.

There are two reasonable argument I have heard.

The first is what some calls spaceship Earth argument: Imagine that you are traveling on a generational spaceship. You have a really good life support system which keeps everyone able to breath, temperature comfortable or bearable and the agriculture pods ticking. It was built eons ago and nobody knows how it really works, but it works mostly. And then one day a bright eyed, young engineering cadet recommends that we tweak a subsystem. Now remember, you have one spaceship and no hangar, no safe harbour where you can dock if things go fubar. Do you let the engineer monkey with the system risking permanent damage?

Earth is like that spaceship. It is vast, and complex, and things affect other things in surprising ways, and we only have one of it.

The second is about international relations and conflicts: Interventions into weather modifications have the potential to be beneficial in one area and disastrous at other areas. You create a deluge here and a desert there kind of things. If Somewhereistan steals the water Otherland's farmers would depend on that's a direct threat to the existence of the Otherland state. Predicting and measuring these changes is challenging. Rectifying harm caused might be impossible even if everyone agrees on what happened, but getting such agreement in a noisy world is hard. This makes weather modification ripe for international conflict. The kind where angry man shoots missiles at each other. Which is better to be avoided.

Australia is "far" from other places, so maybe they are safer in this sense, but memetically they are connected to everyone. Once they proved they can manipulate their clouds who is to tell to Somewhereistan that they can't?

So two opinions/speculations, basically.

Australia is pretty close to New Zealand (5m pop), Indonesia (267m pop), Papua New Guinea (7.2m pop), and dozens of island nations. The Australian wildfires of 2019/2020 taught me that the atmosphere is not that disconnected, as we were breathing smoke from fires thousands of km away.

1. Spaceship earth is heating up and some parts are dying as a result. Someone wants to develop a new technology to cool those parts down. If there was no risk of permanent damage (the technology involves lofting sprays of ocean water), would there still be opposition?

2. Developing technologies for weather control should be avoided because they could lead to conflicts of interest. Can't the same argument be made around any technology?

as they are introducing moisture into a loud in theory they could impact where the cloud releases its precipitation. This could be used for great economic gain to increase growing seasons by expanding wet season of an area. But this would be at the cost of surrounding areas that would get that rain instead. For many areas of Australia that get wildfires it might not be initially apparent if altering where it rains but then could have a delayed impact of years before true consequences known so while they should proceed with the research they should be mindful of the side effects.

First argument seems defeatist to me.

Second argument seems like the realistic outcome but I also think it underestimates the powers that be/will be. The conflicts of interest will be addressed too slowly and the powers that be will say too bad to their opponents.

It's clear that novelty introduced into complex biological systems has long-lasting, higher-order, unpredictable effects. The chemical novelties introduced by humans has manifested numerous unforeseen effects, one of which has been the damage to the great barrier reef.

Then humans come along again with another great novelty they'd like to introduce to this complex system (artificial clouds), which will also likely have "unpredicted", higher-order, long-lasting effects.

>But this time it's good!

>We actually understand what we're doing this time!

>Trust us - we fully understand this complex system and the consequences of our actions now, really!

>We understand with 100% certainty that this is a 100% net good and it cannot possibly have detrimental effects worse than those that have already occurred!

We said the same things about coal and DDT. The skepticism around this artificial cloud plot is warranted and welcome.

Let's just back off for a little while. Rather than add more novelty, let's try to undo some of what we've already added. Take the via negativa. Ease up on burning stuff. Let nature's clouds do their thing. Just relax for a bit.

That's fine and dandy when you're a wealthy Global West citizen. It's not enough when you're a developing world citizen that too wants a big house with a car or two, aircon, potable water, hot water on tap, paved roads, safe urban environments and so on. They can't "just relax for a bit", they are furiously building a better life for themselves, and it's 7 (soon 9) billion people vs 1 billion of Westerners. Unfortunately the only way we have now involves burning fossil fuels and there is no viable alternative (yet).

Effectively this statist position boils down to "screw you, I got mine", which is generally considered unethical. The only alternative is to run forward as quickly as we can, fixing things as we go.

By the way, would you consider "undoing" ozone-destroying refrigerants by banning/reducing AC and fridge use, or would you prefer a technological, "positive" solution of ozone-safe refrigerants?

Ok -- first, let me quote the article:

"Three-hundred and twenty nozzles spewed a cloud of nano-sized droplets engineered to brighten clouds and block sunlight — providing a bit of cooling shade for the coral colonies below."

How big is the Great Barrier Reef?

"approximately 133,000 square miles"

How big is Germany?

"137987.506 square miles"

In other words -- use "cloud brightening" for an area the size of Germany? I would wonder if this is actually a good idea.

How bad is the coral doing? Let's get input from the Australian government":

https://www.aims.gov.au/news-and-media/reef-recovery-window-...

Moderate to High -- without cloud brightening.

Actually, I don't oppose the research. Just be careful if deployments are going to be "at scale".

"We don't know who struck first, us or them, but we know that it was us that scorched the sky." [1]

(note: I am absolutely for trying to save the great barrier reef, and I'm not qualified to judge the feasibility or consequences of this approach, so no moral or other judgement intended. If it can be made to work without breaking Earth production, I hope it gets merged)

[1] https://www.youtube.com/watch?v=JVEHSXL9UPM

Unfortunately there is no staging environment, so we'd be doing it live!

Under the conservative prime minister Scott Morrison, the government has yet to strengthen its climate pledge under the 2015 Paris agreement, as many nations have done in the past year. Morrison has personally ruled out committing to net-zero emissions. Pushing for a technological fix to global warming without moving to aggressively curb greenhouse gases is “sheer lunacy”, says Peter Frumhoff, chief climate scientist for the Union of Concerned Scientists, an advocacy group in Cambridge, Massachusetts.

From Wikipedia (https://en.wikipedia.org/wiki/Scott_Morrison):

The 2020 Climate Change Performance Index ranked Australia in last place for its climate policies and was the only country to score 0 for the same metric in 2021.

During the 2019–20 Australian bushfire season, Morrison dismissed suggestions of a link between Australia's emissions or policies and the intensity of the bushfires and initially downplayed the influence of climate change on the fires, but later admitted that climate change may have contributed.

Morrison declined to set net-zero emissions or other climate change targets, unlike other world leaders. Morrison allegedly requested climate change policy targets be removed from a proposed 2021 Australia–United Kingdom trade deal and initially suggested he would not attend the 2021 United Nations Climate Change Conference, but later confirmed that he would.

Morrison's government pledged that Australia would aim to achieve net zero emissions by 2050, but did not introduce this into national law; Morrison said he believed market forces and not government regulation can address climate change.

His government's climate action plan has been criticised as "lightweight", "meaningless", and a "mockery" that contains "no policy or strategy whatsoever".

Market forces, sure.

How much CO2 is emitted by those boats with their high-powered water pumps? How much noise is injected into the water body when these vessels operate in numbers day in, day out? How many vessels and hours of operation will be needed to have a cooling effect? Where do the clouds, where does the water go once it is vaporized and left drifting?

Come to think of it one could imagine to suck huge quantities of marine water to vaporize it and let it drift as clouds over land; thinking in the abstract, that could contribute to more shade, lower temperatures and more precipitation over hot and arid areas, thereby improving conditions for plants, animals, and humans. But, and this is a big one: how much energy will this need? How is that energy produced? How much water would one have to evaporate? What are the consequences for marine life? What are the consequences when the next government decides to cut funding? And what about the salt content of the aerosol, for certainly it will be utterly uneconomic to desalinate the water prior to spraying it?

My hunch is that those figures won't work out and that artificial clouds over the Great Barrier Reef also won't work out. The reef is called great because it covers an area of ~344,400km², roughly the area of countries like Finland, Congo, Germany, or Japan. According to the USGS[1], the water in a cloud with a volume of 1km³ weighs about 500,000kg. A 1m thick cloud layer over said area has a volume of 344.400km³ if I'm not mistaken, so weighs around 172,200,000kg. So in order to work one would think it to be requisite to spray in the order of a hundred million kg of water like almost daily into the air from seagoing vessels. There's an almost constant wind over most of the oceans so low-faring clouds will disperse in a matter of minutes or hours; the clouds however would be most desperately needed around noon each day which complicates things. Perhaps one could move the ships to upwind locations each day so clouds generated in the afternoon and the night get a chance to drift over the reef.

But imagine to do that for a country-size area: You'd need a fleet of tens or hundreds of thousands of not-so-small vessels. I cannot imagine photovoltaics to be a sufficient source of energy (for one, space is very limited on any vessel, and ironically, the vessel's reason for being there is to reduce impact of solar power). You'd need nuclear or hydrogen because otherwise you'd have to burn through untold tons of fossil fuels.

At any rate, the waters will not be calm anymore. The noise of the evaporators and the propellers will be deafening in the air and in the sea.

All told, a badly thought-out publicity stunt.

[1] https://www.usgs.gov/special-topics/water-science-school/sci...

I highly recommend reading about this first before reacting.

1. It isn't about using the ocean water to make clouds. It is specifically about using the salt as a cloud condensation nuclei (CCN)

2. The concerns about CO2 and noise are well-founded concerns. They aren't intractable, though. For instance, if this really worked, maybe solar powered zeppelins would be the way to go (oh, please let it be so)

3. Unless scientists conduct research like this, we won't be able to answer the rest of your questions. They are empirical in nature.

@1 the part of the salt being an essential ingredient did escape me so thanks for pointing it out. It does make the whole thing more believable because then maybe (if it works) you can have more clouds for a fraction of mass moved.

@2 yeah I'm all for zeppelins (and trains). It's not immediately obvious to me how to make use of zeppelins (or trains) for this project but maybe they could be used to collect solar power (but do they have enough buoyancy for large solar panels?)

@3 I'm not against sending experimental vessels to the sea and spray water all over the place in order to find out what happens. I'm all for doing some boundary sanity checks beforehand and during such undertakings to see whether basic physics checks out, and this is what motivated my post. I live in Germany, a country with roughly the size of the Great Barrier Reef, and I'm not sure I have a good handle at the size of this country—it is too big. I'd be happy to hear from someone else an estimate for the size, number and horsepower of vessels required to pull this off. If it's a thousand cargo ships, that sounds like an upper bound for being reasonable. If it's a thousand aircraft carriers, then forget about it. If its hundreds of thousands of mid-sized vessels, good luck with acquiring or building, outfitting, maintaining, manning, catering, harboring, and fueling them. Maybe modified oil drilling platforms are better suited for a task like this.

> But, and this is a big one: how much energy will this need?

It's an interesting thought, Australia is in a good position to leverage renewable energy however the boats would be burning diesel. It's one of those "Futurism meets reality" issues, where grand ideas fall apart in application.

Scott Morrison is a muppet, and the Federal Government has their head burried in a pile of coal. We're extremely well suited to curb emissions and we should. Let me preface the below with that.

I have no faith that we will, as a global society, curb emissions. There are too many players benefiting, and newcomers who seek to benefit from the same dirty industrialization the west did. At no point in history have we ever come together as a globe on any topic whatsover, so I don't understand why we think we will now. So I think we should be focusing on developing the technology to remediate this mess, from all the different angles that make sense. Alongside reducing emissions obviously, carbon taxes, carbon rebates, whatever it takes.

But we're way down shit creek already, and our paddle looks like Scott Morrison, so we better start coming up with better ideas than politics.

This kind of experiments should be done only by people with previous experience culturing corals. I see at least two possible problems here.

I would be happier if nobody did these kind of experiments. I have the feeling that playing with the weather may be our last and most stupid failure. Doesn't have to have crazy consequences after the first, second or third time. But at some point it will just turn everything to sh*t.

Humans have been playing with the weather ever since we started cutting/burning down forests faster than they can grow back.

That doesn't read like an endorsement of planned geoengineering.

AdrianN was responding to a comment about "crazy consequences" to messing with the weather. His point was that thus far there haven't been any, despite centuries of human-driven weather changes.

> thus far there haven't been any [crazy consequences], despite centuries of human-driven weather changes.

which obviously is not true, right?

The only type of geoengineering I would endorse without much hesitation is sucking CO2 back out of the atmosphere. But I don't think that the weather system is sensitive enough that we can't try nudging it with measures that are easy to stop and whose effects only last a couple of years (e.g. injection sulphur into the atmosphere).

I see many issues with weather modicifation. I would love to see the coral reefs, and it starts a lot closer to the ground.

Weather modicifation has been a dream military tool, with some unprecedented applications. They are as far away from saving the environment as you could get.

Everyone running a fossil fuel engine is engaged in their own little bit of weather modification...

Orders of magnitude should matter in an insightful conversation.

The coral reefs are in trouble because of how many of those car engines there are. Each one is orders of magnitude smaller than this proposal, but together? I think that’s relevant in this case.

> it starts a lot closer to the ground

Climate change will harm coral at higher latitudes, at a slow enough rate they will migrate southwards, the rampant agricultural runoff will keep going regardless of the climate though and it has just as much a negative impact. Talking about fertilisers flowing into the reef and farmers causing much of the damage is a quick way into political suicide. It's not an easy issue to solve in a country with a 24 hour news cycle full of ever more outrage.

Australia has been seeding clouds since the 1960's uninterrupted. Maybe just give us the benefit of the doubt here.

> Australia has been seeding clouds since the 1960's uninterrupted

So... can we conclude yet that it does not work for saving the coral reef?

It's good to hear from an Australian that environmental policies like fire management and cloud seeding have made ecological disasters a thing of the past in your part of the world /s

It was a lack of application of known fire management policies, due to reduced spending, that escalated the impact of the fires.

and yet most of the Australia is still a desert.

Can't tell if that comment is tongue in cheek, but the goal was never to change the desert. Cloud seeding is mostly used to supplement already arable land for crops and hydro power I think.

Why would coral culturing specialists like Madeleine van Oppen be the best at testing atmospheric alterations? Do you mean that the ultimate effects on the corals are important, rather than just a reduction of insolation?

Australia as a whole doesn't even believe climate change is happening or should be stopped, so...no.

I don't get that impression from the public, but it's clear the federal government isn't particularly interested in changing anything to help.

It is nice to see some individual states giving it a crack, South Australia ran for one full week on renewables recently, and has fairly high renewable input in general. There are solar-hydrogen plants, desal plants and green-steel initiatives all underway as well. I can see a lot of good happening, albeit a bit late.

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