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
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.
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.
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.
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.
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).
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.
No we're not engineers because we find it OK when the poll results get displayed before you even vote. Engineers would study a problem including user experience and user expectations, hence only tell results after the poll has finished or at least until after the user has voted (in low-stake polls like this one).
Yes we are engineers because we find it OK when the poll results get displayed before you even vote—shows how little we know and care about the rest of the world.
> Generally this is not seriously discussed by experts as a solution to global warming not because it is not feasible, but because it would diminish the sense of urgency
Let us say it is not being discussed because it is not feasible. Unless of course we build massive nuclear power plants in Antarctica with all what that entails. We are not any time soon in a position where we can produce any nontrivial amount of solar or wind energy in the hostile environment of that continent, plus it's dark night down there for half a year each year. Meaning the only remaining option would be to ship coal or oil down there to burn it so we can cool air to –140°C, obviously a non-starter if there ever was one.
> and discourage the much more prudent and affordable approach of simply reducing emissions.
This. The entire plan is madness: you'd burn two tons of oil and coal to get rid of part of what burning one ton of oil and coal leave behind in the atmosphere. It is not clear to me at this point if it is at all feasible to use fossil fuel to get more CO2 out of the atmosphere than burning it puts into the atmosphere in the first place. Because in this household we obey the laws of thermodynamic. And if it's possible at all it's not easy to see why continuing to burn oil and coal and capturing the CO2 at other sites should be better than not burning part of those fuels and capturing the CO2 right at their point of emission should be the better option. It is a hare-brained plan.
> Let us say it is not being discussed because it is not feasible. Unless of course we build massive nuclear power plants in Antarctica with all what that entails.
Maybe it really is because it's not feasible, I concede that's not something I can really know. But nuclear power plants are not necessary. As the paper sets out, there is abundant wind energy in Antarctica. Setting up a medium-size (1200 MW) wind farm on the Antarctic coast is actually not a crazy proposal, since the construction can be undertaken by ship alone.
Moreover it's very clear that the energy required to freeze one ton of CO2 is substantially less than the useful energy obtained by its combustion (this is intuitive from the magnitude difference between heat of combustion and enthalpy of sublimation: combusting one mol of pure coal to CO2 liberates 393 kJ, freezing one mol of CO2 out of the air consumes 26 kJ). In no way does that violate thermodynamics; the CO2 still exists, it just isn't doing any harm.
This project would not just ameliorate global warming, it could allow useful exploitation of all the remaining global fossil fuels.
is where you lost me. Hell coal is projected to get burned by the megaton for another half century or so because China and India have those resources and that demand. Mankind does not currently have surplus renewable energy.
There isn't a single global account of electricity generation and expenditures. If your windmills are humming in Montana, and demand for electricity relatively nearby right now is already met, you have surplus energy to either use or store; China doesn't factor into it.
Maybe if you were allocating resources across the world's economies, it would be better to invest in solar panels in Shanghai than capture carbon in Billings, but that's not the actual situation.
> Mankind does not currently have surplus renewable energy.
On the contrary - we have a lot of surplus renewable energy, and it's a problem [1].
Energy isn't fungible. 1 MWh in Texas at 12:00 on 4th July is not the same as 1MWh in London at 23:30 on 25th December.
Energy consumption vary a lot through the day and year. Energy production of solar and wind vary a lot as well, and these variances aren't correlated with each other.
Most big scale energy grids are created with the assumption that every millisecond energy produced == energy consumed. When this isn't true - frequency in the grid rises or drops. If it drops too much you just have blackouts, if it rises too much - devices blow up AND you have blackouts until you replace the blown up devices.
Even if a grid as a whole has energy deficit - it's often true that one part of the network is producing too much but the power lines between them might not be "thick" enough to transfer all that energy to the part of the grid that has deficit at the moment.
If we moved completely away from fossil fuels towards renewables - to serve energy needs of customers we would need a lot of overcapacity (because you can't count on sun and wind producing at 100% power all the time). Usually the overcapacity for wind is 2x and for solar is 10x compared to traditional sources. Better batteries might change that, but it still won't be 1x. So when there's a very good weather grids with a lot of renewables will by definition produce too much energy.
There's a lot of factors, and in practice even in countries with less than 50% renewable power installed - often they have too much renewable energy. This will only get worse as we replace more energy production with renewables.
Big batteries like the one in Australia are very profitable and solve short-term (sub-hour) balancing, but aren't big enough to shift the solar production peak in the noon to the consumption peak late evening.
So indeed we have a lot of surplus renewable power already that gets wasted every day and causes problems, and it will only get worse.
Your assessment of the properties of the display specifically seem to go counter what I perceived as a convincing argument by the OLPC guy brought up in a TED talk at the time, namely, that the two biggest cost factors of a new laptop are marketing and the display unit. He then argued that the project can largely just do away with marketing altogether (plausible) and went on to say that even displays that come out of production with a single pixel error have a massively reduced price tag. From that I concluded that the project could reasonably build cheap hardware if only they went with no advertising and run-of-the-mill display units that narrowly failed quality checks.
Nothing in that talk hinted at the possibility that instead of opting for a established and proven technology like LCD they'd choose to go with RDF (reality distortion field) displays instead.
I notice this kind of response anytime I say something that goes against the faith of the OLPC believers.
If you feel something I said is factually inaccurate, then please point it out specifically.
Otherwise, I believe all my points have been proven out. Quite simply, we can all observe the fact that nobody is using a Pixel Qi display or any technology related to it. If your speaker's claims about "Nothing in that talk hinted at the possibility that instead of opting for a established and proven technology like LCD they'd choose to go with RDF (reality distortion field) displays instead." were true, then I'd have been proven wrong and the display industry today would be worshiping at the feet of Jepsen.
One Display Unit Failing QA Per Child? There aren't that many failed displays in the world! Especially in the cost, size and energy budget of a hand crank computer.
