How a Solar Revolution in Farming Is Depleting Groundwater | Hacker News Reader

How a Solar Revolution in Farming Is Depleting Groundwater

e360.yale.edu

124 pointsrustoo129 comments

I know some farmers in North Texas where they are pulling water out of a depleted aquifer. The water is starting to get salty so they're adjusting to salt tolerant variants of their crops. The ground is also starting to drop due to the aquifer draining. It's crazy to see

In the Santa Clara Valley farmers pumped enough water out of the ground in the early 20th century the ground dropped a dozen feet in some areas. Bad thing too is that once an aquifer settles like that it's carrying capacity is permanently reduced.

Also in southern California there is a fair amount of previously productive farm land that is salted up and useless. That'll happen to the north Texas farmers you've mentioned. If they're having to switch crops they have another ten to twenty years and it's all over.

Edit: Even better Jakarta is sinking so bad because of ground water pumping that the government plans to abandon it.

It's odd that foreign media reporting the Indonesian government plan to move the seat of government from Jakarta to Borneo as primarily motivated by the sinking of Jakarta (it affects the northern part of Jakarta, while the goverment is mostly operating in Central Jakarta), while the other more important (to the government) reasons are usually under-reported, such as to reduce the java-centric development, improving the government's efficiency by moving various government agency closer together instead of scattering everywhere over the huge megacity with traffic jams everywhere, and improving the government image because foreign diplomats will arrive in a pristine, green city instead of concrete jungle with bad air and traffic jams everywhere.

I did the math once and the amount of water we’ve pumped out of the aquifers worldwide and not replaced is worth more than a mm of sea level rise.

Please show the math and sources, I would love to see the sauce.

Me too because that sounds impossible to calculate.

What difficulty do you see? It's not going to be enough to appreciably change the ocean area, so isn't it just volume divided by the area of the ocean?

I think it would be 1) how accurate are aquifer and coastline topography measures (1 mm wouldn’t be far off but what about a meter? That’s a lot of inundation). And 2) how much has subsidence permanently decreased the carrying capacity of aquifers?

It could be a thing where only 50% of what is extracted can be returned. Either theoretically or safely (eg, earthquakes).

Makes sense, thanks.

Permeability, amount of precipitation, land usage, evaporation, avg temperature, temperature variation, soil composition, erosion, wells, flood plain, wetland, etc.

There’s a calculator that works out how many acre feet of water it takes to raise the ocean level, and the UN has estimates on total global aquifer depletion. There were a couple ways to calculate it. I’ll see if I can reproduce my work.

OK, I am finding that my memory was faulty here. Global aquifer depletion isn’t equivalent to 1 mm of ocean volume. It’s equivalent to 3 mm of ocean volume per year (2010: https://www.ngwa.org/what-is-groundwater/About-groundwater/f...)

    Groundwater is the world’s most extracted raw material with withdrawal rates currently in the estimated range of 982 km3 /yea

Surface area of the ocean:

361,000,000 km²

1,000,000 mm per kilometer means 361 km³ per millimeter of sea level, ignoring inundation.

The USGS estimates that just the US has lost 1000 km³ from 1900-2008, most recently (2008) at rate of 25 km³ per year which is at least another 400, so let’s call it 1400 km³ which is almost 4 mm. Just for the United States.

I can no longer find the studies that estimated global depletion of aquifers. I don’t know if my queries changed or SEO rotted the search engines. But if it’s anything like the US, (2.5% a year) then we are over 40,000 km³ globally. Which is about 10 centimeters of sea level rise we could mitigate if we could refill all of the world’s aquifers.

I know California has been experimenting with this, but we know with boil orders that untreated water made it into the water supply. What happens when the same thing happens with groundwater injection wells?

Related: Humans pump so much groundwater that Earth’s axis has shifted, study finds

https://www.cnn.com/2023/06/26/world/pumping-groundwater-ear...

I used to joke that once the ice caps melt and fiddle with the earth’s angular momentum, I’ll have enough hours in the day to get everything done. Better WLB these days. And also ice caps melting is less funny than when I said it.

Correction: 10 cm

https://news.ycombinator.com/item?id=39736050

I remember reading about how in the Soviet Union, there were places they were irrigating with brackish water and how they were now infertile. The obvious conclusion was that the Soviet economic system was busted to permanently destroy land for some temporary gain.

The American equivalent is the dust bowl. The ancient equivalent is the desertification of Mesopotamia. Etc. etc.

Humans are bad at long term thinking.

Which species is good at long term thinking?

Many animals move on before they destroy the fields and return later once it's regrown.

Probably not much thinking but this is how your species survives. Perhaps humans think too much.

These days I feel like it's more that every attempt at central planning gets weighted down in conspiracy theories.

Sadly though, the public's reaction isn't totally unwarranted due to what has become acceptable behaviour for politicians.

Termites are pretty good. It's too expensive for them to rebuild their nests all the time so they don't destroy their surroundings.

That’s different, it happened under capitalism, so it was an unforeseeable natural disaster that doesn’t reflect on the system in any way.

We've been farming for 10,000 years, and the vast majority of farm land is still fertile.

We have not been farming for 8 billion that long. The scale of what’s happening right now is unprecedented.

And thanks to fossil fuel fertilizers and land degradation a lot of topsoil is less than 60 harvests from being degraded completely.

Why can’t it be amended? My region has pretty shitty clay soil but I’m able to mix in compost, mulch, and other amendments and grow all sorts of tropical fruits and other plants that shouldn’t grow here. Am I missing some reason why the farmers have to rely on topsoil?

What do you mean, why do we have to rely on topsoil? That's what almost all food grows in. What else would you effectively grow food in? What you're doing by adding compost is basically creating topsoil yourself. Amending can only go so far. In some cases it's literally just been degraded away like when deforestation causes land to be more susceptible to erosion by flood or landslide. You may be able to make soil amendments work while you have fertilizer and added nutrients derived from fossil fuels, but once those aren't economical, you're getting out what you put in naturally, which is a lot less than modern industry has acclimated us to, and probably a lot less than in historical times if the topsoil quality was drained of nutrients that can no longer be replaced.

Is it close to these huge sinkholes in Turkey? https://www.dailysabah.com/gallery/turkish-farmers-worry-abo... Because these in Texas seem tiny in comparison https://www.texastribune.org/2023/08/16/texas-drought-heat-a...

Ancient subterranean water aquifers are not a sustainable resource in the long run unless a recharge program is implemented that puts as much water into the system on a yearly basis as is withdrawn.

See the Ogallala Aquifer under the Midwest:

https://www.kcur.org/2023-04-04/with-the-ogallala-aquifer-dr...

The power source for the pumps is sort of irrelevant to the question, it could be fossil fuels, nuclear, solar or wind and the end result of uncontrolled extraction is always going to be exhaustion of the resource.

The problem here is people relying on unsustainable sources of water and then using that water very inefficiently. Relative to farming, cleaning solar panels is a drop in the ocean. In terms of surface area, it doesn't really compare. And of course it doesn't help that people just let the excess water drain away. They pump it up, use it and, then it drains away to rivers and eventually the ocean. Instead, they could be recycling that water and using it for irrigation. But because the water is cheap, nobody cares about it. So it's drained and lost.

In the Netherlands which, depending on how you look at it, is technically mostly a swamp with really awesome drainage and pumps, we have ground water shortages. Reason: farmers like irrigating their land (much of it below sea level) with ground water because it is cheap. But they also like to keep their fields well drained so their plants don't rot in the field. So they are actively draining water from their lands while using ground water to keep them at just the right level of wetness. They use massive amounts of water and the drained water is rich in phosphates and other nutrients which is causing all sorts of issues down stream.

Not sustainable. The climate in the Netherlands while changing is still quite wet. And besides, two of the largest rivers in Europe flow through the country. Mostly we have issues with water levels of those being way too high, not too low. In other words, there's plenty of water. Except in the ground. Getting rid of excess water is actually a major engineering challenge.

Water companies are also tapping into the same unsustainable sources because its cheap and doesn't need a lot of filtering because it's also clean. So there are water shortages and calls for people to use less water, irrigate their lawns and gardens less, and take shorter showers all while we are dealing with getting millions of tonnes of excess water to the North Sea.

Cleaning solar panels? Did you read the article? It's about solar pumps enabling aquifer exhaustion when used for agriculture

This is exactly what happens in Spain:

https://www.euronews.com/green/2024/02/01/spain-expected-to-...

Agriculture is responsible for 80% of water use. Because water is not market priced for farmers, farmers use very inefficient surface irrigation, causing 50% of water to vaporise.

Then nobody does anything and wishes the government pays them to switch to more efficient irrigation systems.

Edit: Looks like government is doing exactly this - paying farmers to reduce water usage, instead of having a fair price for the water https://www.catalannews.com/drought/item/government-and-farm... Hopefully this leads too a real change is not just a socialist solution kicking can down the road.

The margins are doubtless so narrow that it's not feasible, but pumping during the day into a storage tank, and irrigating at night (while evaporation is relatively low) would be a way to slightly improve soil (though not aquifer) recharge.

Certainly it would require less water volume, but again, the infrastructure costs for panels + submersible + storage are probably untenable in precisely the places this is needed most (and where the impacts of depleting the water table will hit the most).

If you don't irrigate during the day in hot climates some crops will die, and the yields will be terrible for most.

> If you don't irrigate during the day in hot climates most crops will die

That is clearly not true.

Most crops are fine with watering after sunset / before sunrise.

Fair. I just edited my comment because I combined two concepts and muddled them together. It's more common to suffer a poorer yield than total crop loss. But crops like tomatoes can die from lack of water during high heat days if the heat lasts for several days. Also, irrigating only at night (not just evening, but over night) can contribute to fungal and disease issues with some crops.

Sure, cucurbits and solanaceous crops and prone to humidity / water induced fungal attacks. Tomatoes are better watered at ground level (refer other thread about drippers) or even just flood irrigation.

Tomatoes are actually pretty robust, if you grow them properly.

The way I was taught to maximise survival / yield in hot climates is to grow as seedlings for a few weeks, until they're maybe 30cm or so tall. Dig holes ~ 25cm deep, flood / drain / flood / drain - and then take all but the upper few branches off the seedling, and plant, backfill with soil, so about 5m is above-ground.

Because they have adventitious rooting you've effectively just given them a massive reservoir of water retention. This is obviously expensive at scale (though not intrinsically infeasible) but works superbly well in hostile, arid climates.

I expect the next decade or two will force a lot of changes to the way food is grow in already marginal climates.

Doesn't that mean we should stop growing crops in such regions?

Permaculture maybe possible

It means that method of farming is a bad fit for that climate, yes.

Its a much more complex problem though. Most farms in the US depend on debt and subsidies to get by. That money comes with strings attached, from the yield required to cover expenses to subsidies that require mono-cropped fields that basically sit idle in the off season or when a crop fails.

There are different techniques that could be used, but none of them will match the sheer tonnage of yield from a mono-crop drenched in fertilizer, herbicides, and laid out in a way that allows for massive tractors and combines to be used. All of these methods cause huge damage to the land, but again I'd argue we've left those farmers with little to no choice in the matter given how our food system is designed.

No, groundwater is renewable in a lot of places, like in much if the Sacramento Valley, where it rain 20-30” a year.

But in the Fresno/Bakersfield area of California, with only 5-10” if rain per year, over pumping is making farming uneconomic. See SGMA https://en.wikipedia.org/wiki/Sustainable_Groundwater_Manage...

> pumping during the day into a storage tank, and irrigating at night

Or, irrigate during the day but use sub-surface drip irrigation. [1]

1. https://www.ksre.k-state.edu/irrigate/oow/p05/Evett.pdf

Yes, sub-surface, or drip close to root zone, is perfect -- however that's really expensive, in terms of capex as well as maintenance, harvesting, etc.

Drip systems tend to require a) a lot of pressure, and b) a very consistent pressure, to get reliable output. These are also expensive to buy & run.

Drip or leaky-hose type underground systems are difficult to maintain (I've tried!) just because you can't see them. The way you find out something's wrong is usually because a plant or an area is looking very very happy, and other plants / areas are dying off.

Under-mulch is good, but doesn't lend itself to broadscale cropping as described in TFA.

> These are also expensive to buy & run.

Long-term, it’s the cheapest option if you want to farm in an arid region.

Drip is used quite a bit in Northern California for higher value crops like tomatoes, but it's too expensive for normal crops. It also seems like a non-starter for smaller scale and poorer farmers in developing nations; that's a lot of CapEx for generally lower value crops.

> that's a lot of CapEx for generally lower value crops.

We’re not disagreeing. Those farming regions are not viable long term unless the economics change dramatically.

How are current farming regions without such systems not viable?

That’s the vast majority of current farm acreage in the world.

Also, evaporation losses at leaf stomata can be adjusted with carbon dioxide.

If one tries this approach I'd recommend pumping into a holding pond, ideally up hill from the land to be irrigated. Tanks would be absolutely massive for a crop on any meaningful scale, especially if its big enough to be putting a dent in the aquifer.

> If one tries this approach I'd recommend pumping into a holding pond, ideally up hill from the land to be irrigated. Tanks would be absolutely massive for a crop on any meaningful scale, especially if its big enough to be putting a dent in the aquifer.

Sure, but almost all the countries TFA mentions are generally farmed by small landholders, so irrigation via stored water is not infeasible. The mammoth style broadacre tiny-return-per-hectare, heavily mechanised, fertiliser- and insecticide- reliant style agriculture popular in the USA isn't so common in these places.

The 'dent in the aquifer' you mention (and TFA dwells upon) is because there's thousands of people doing the same thing at the same time to the same aquifer for years on end.

Regrettably TFA doesn't talk volumes, other than three mentions of 'cubic miles'.

Apart from an exasperated 'why do they use anything but metric?' sigh, it's also obviously a heavily aggregated figure across large geo regions.

These small holdings with their panels + pump per field, pulling from an increasingly deep water table, are presumably extracting probably in the range of 10-20 kilolitres of water per day - the size of an average plastic water tank that has a one-off cost about the same as a submersible DC pump + panels. (Lined steel, concrete, etc, become more attractively priced at larger volumes.)

So, yes, absolutely, if your geography allows, then put in a megalitre+ sized hole in the ground up-hill, cover it to reduce evaporation & algae, fence it to prevent animal damage, etc. Happy days.

I’m very naive in this space. What percent of water extracted makes its way back into the water table and how long does it take? I assume you lose some to the plant that is harvested and some to evaporation. But how much makes it back?

I am too but the answer is zero, and nobody knows but probably a long time. The whole Central Valley is like 30 feet lower now. A bit of rain isn't going to fix that.

Probably just a fraction. A lot probably evaporates and anything that the plant absorbs and incorporates just goes away when crops are harvested and shipped elsewhere.

From what I’ve read, it takes a very, very long time to replenish the water table. Eons.

I'd see what the Dutch water suppliers have to say about it, pumping up ground water and managing the water table is kind of their thing.

Apparently pumping up, yes, managing, less. See this comment here:

https://news.ycombinator.com/item?id=39732506

> ... ground water shortages. Reason: farmers like irrigating their land (much of it below sea level) with ground water because it is cheap ...

It should be noted however that this shortage is happening because the water suppliers are refusing to pump up more water than is sustainable. This is rather different from the free-for-all depicted in this article, and is in fact what I mean by managing the ground water.

They are refusing because of the previous over-pumping.

Each aquifer is differen: some recharge quite fast with two rain seasons. Others take thousands of years.

What are some solutions for water table depletion and how comparably sustainable are they?

How much water is extracted from air by PV panels that output H2O, and what are the impacts?

Do drilling and fracking consume lots of water and create holes through aquifers? Do holes in aquifers cause aquifers to drain out to lower chambers of the earth?

Historically, people have moved to where the water is.

Is there a subsurface ocean on Earth or Mars?

Is there enough of a thermal gradient between very deep wells and surface water to generate energy?

How many humans operating humanoid robots operating construction equipment does to take to build irrigation canals?

Perhaps helpful new solar distillation tech for #Goal6 #CleanWater:

- "Desalination system could produce freshwater that is cheaper than tap water" (2023) : "Extreme salt-resisting multistage solar distilation with thermohaline convection" (2023) https://news.ycombinator.com/item?id=39507692

Perhaps there are already sustainable salt-tolerant plants without GM; algae, kelp, sargassum

There is plenty of salt water on Earth. Does life on earth depend upon and/or derive from ocean thermohaline cycles?

> What are some solutions for water table depletion and how comparably sustainable are they?

Water harvesting has been successfully applied to thousands of villages in India and parts of northern Africa.

The Paani Foundation is especially amazing, as they annually lift hundreds of villages from dry wells and tanker dependence to tens of feet of water in wells and ponds in as little as one rain season using nothing but planning and cheap labour (the villagers).

I see videos of successful bund dig operations; digging half-craters to catch water apparently keeps the water from flashing off.

Tilling turns topsoil to dirt due to solar radiation.

No-till farming methods like residue mulching prevent soil depletion and retain water in topsoil; in order to create healthy soil as an output.

Hugelkultur is basically residue mulching and rainwater catchment.

Removing all of the trees reduces the level of water in the air and soil.

What sorts of agricultural machines can service bunds, raised beds, and hugelkultur mounds instead of rows?

> Tilling turns topsoil to dirt due to solar radiation

and oxidation.

You can think of the water as ancient. It's been there for a while and it took a long time to get there.

The water in most of the big US aquifers is at least 10,000 years old. There are some exceptions like the Edwards Aquifer in Texas but for most, rainwater is irrelevant. The water was put there by glaciers during the last ice age and once it's gone, it's gone forever.

This is why most groundwater pumping is properly called water mining.

I simply assumed it was refilled by rain … darn half remembered geography lessons!

Amazing - if it was a mineral or metal then there would be a mining company charging market rates for the mining … what is happening in this case?

It's a pretty great deal if you are a farmer. In California, you have unlimited rights to pump water from your own land, which extends to the ground underneath. So they just keep drilling deeper. Such a great system for the people who own land, I have no idea why anyone would complain about it...

FTA: "Irrigation is responsible for around 70 percent of the global underground water withdrawals, which are estimated at more than 200 cubic miles per year. This exceeds recharge from rainfall by nearly 70 cubic miles per year."

So 65% makes it back.

These numbers could be wildly innacurate. We have no good way of measuring this at scale and end up using modeling to answer these questions. Models are only as food as the inputs though, and we don't know what we don't know.

In the real world these systems are way too complex to have specific answers like this. We simply don't know, and have no way of knowing for sure.

The best, and my opinion only reasonable, answer to that kind of scenario is to just not intervene. We shouldn't be sucking water out of aquifers at such a scale that the water level drops when we have no idea of the long term impacts.

Pumping water is useful only when coupled with increases in water retention and runoff prevention. Like what is happening in some (arid) places like Northwest India: https://www.youtube.com/watch?v=79VUAFq2rbg

I don’t think solar powered irrigation is practical.

To water 10 acres of orchard in northern California, where our water levels are “good” (wells are 100-150 ft deep), we need about a 25 hp (20 kW) well pump. That’s ~2 kW per acre.

A typical irrigation cycle is on the order of 10-20 hours. So budget about 20-40 kWh/acre for a cycle, and repeat every 10 days or so (crops need to dry out between waterings else disease spreads.)

In theory, a kW of solar panels charging a 20 kWh battery for 10 days should work to water 1 acre for an entire summer season, at a capital cost of a wildly uneconomic cost of perhaps $20,000 per acre.

These are my wild guesstimates informed by some orchard experience, but please correct me if my numbers seem badly amiss.

ps: With PG&E power, we currently pay about $400/acre, per year.

There are no batteries involved with the type of solar pumps the article is talking about. They are likely 3 phase pumps powered by variable frequency inverters. The inverters are similar to the VFD¹ motor drives commonly used with industrial machines.

I'm not sure where you came up with a $20,000 cost estimate but it's likely a lot less than that. Particularly if you buy the cheapest stuff direct from China, avoiding avoid the dealers/installers who are probably marking up the equipment by more than 100%. Solar panels and the associated electronics have drastically dropped in price for the past several years. It should be possible to get 200 watt panels for $50-100 (or maybe even less if you buy a lot of them) That's something like $250-$500 per kW of panels. Make it $1000/kW to cover mounting hardware and wiring. The pumps / inverters are maybe a few thousand for a fairly large system.

I'd say the total should come closer to $5,000-$7,000 per acre based on the power requirements you specified.

[1]. https://en.wikipedia.org/wiki/Variable-frequency_drive

Hoogle cultures,and capturing runoff reduces your agricultural water needs.

https://permacultureapprentice.com/permaculture-water-manage...

> In theory, switching from diesel or electricity to PV pumping should eliminate greenhouse gas emissions. But in practice, farmers often use their solar pumps to supplement existing pumps, rather than replacing them. And, however it is pumped, the extra water available will also encourage farmers to adopt more intensive farming methods, using more fertilizer and machinery to grow thirstier cash crops, increasing the carbon footprint of the farm.

When given the chance of reducing your footprint or improving your life, is it that surprising this is the outcome? Specially in developing countries.

Farmers often don't have a choice on this. A vast majority of operations depend on debt and government subsidies just to get by, both come with strings attached related to both farming methods used and required yields.

I'd propose that the more sustainable solution here is to help get out of a farmers way (both financially and regulatorily) rather than trying to encourage get another round of changes. I'm assuming the encouragement would have to come similar to the current ones, as either legal requirements or strings attached to the money.

Farming is a nearly impossible business to be in today with depending entirely on debt and subsidies, at least in the US. Prices are insanely low relative to the cost and risk of raising animals and farming crops. Until that problem is fixed, farmers have little choice other than to look for expense optimizations anywhere they can (regardless of long term damage) and follow whatever rules are tied to the money they take.

What's the state of technology in producing fresh water from sea water? Isn't there any serious progress making it more efficient and cheap?

It's become progressively cheaper through incremental engineering improvements. The cheapest way is generally reverse osmosis, especially on water that is just brackish.

But it's also generally cheaper (per unit of saved water) to just use water more efficiently. Agricultural water use can be enormously economically inefficient in the US.

I've wondered if all the solar panels being put in will mean some areas will never get electrical infrastructure. The local governments will see a region where the only industry generates its own power.

Why not just tax water-hungry crops?

The bigger issue is that 1/3 of crops are used as animal feed. No matter how water efficient they are, you still need 10x as much of them for the same amount of calories.

It'd be much easier and have a bigger impact to just go plant-based.

I've read about that, related to farmers shopping down the rain forest in Brazil (to grow beans for hamburger cows). But I don't think it applies to poor development country farmers?

It's not as if the farmers in India are feeding cows and everyone feasts on hamburgers. And in Yemen, they're growing that qat drug (not meat)

They are, more and more. They richer a country becomes, the more they demand meat and animal products, the more they overconsume resources relative to provided calories/protein.

And who cares about India, when we're already screwing ourselves over well enough: https://www.vox.com/the-highlight/23655640/colorado-river-wa...

70% of the water used from the Colorado River (which is slowly losing water) is used for crops, and 80% of that is used for feed production. But let's stop taking so many showers, that'll fix the issue.

Thanks for the link, didn't know there's that much feed production in the US

Who cares about India -- hmm, doesn't ground water depletion have quite different consequences:

In the US, there'll be fewer hamburgers. While in India, people will starve, famines?

> It'd be much easier and have a bigger impact to just go plant-based.

Ok but this is a non starter since myself and a huge chunk of the western population will say no thank you.

Viewing humanity like a single organism, this is the strategy where like a slime mold we expand to consume all resources, then most of the organism dies off while some number of spores go on to continue to the process elsewhere.

If we'd like that not to happen, because we like our civilizations and like not to see them crumble, we must develop some kind of governance mechanism to prevent slime mold behavior.

Seeing so many conversations about resource exhaustion/climate change/ecosystem collapse boil down to "nunht uh" is.. I can't even say tiring anymore. I'm beyond tired. At this point we're gonna find out exactly what behavior is encoded in human nature one way or another.

Picture a roller coaster where the carts have little steering wheels .. that do nothing. We like to imagine we are in control, but zoomed out we behave quite predictably, chasing that unsustainable growth.

I feel you, and I'm not sure how to explain this to children. How honest should we be? I believe there is no version of this that ends well, we are left with outcomes to our decisions on the spectrum of awful to really awful. There is no arguing with physics.

I actually argue the opposite zooming out. Zooming out our trajectory is up and to the right, like a hockey stick. Almost on every level. We’ve done that with all these disasters that have always happened. Almost like we can innovate or something

Technocrats on this site are very fond of your argument, so fond that I stored the reply I saw years back when someone else said the same thing.

There is no monitoring dashboard for the planet. News articles like this are your warnings. There is no innovation to be had that fixes global aquifer levels.

>>>

Original Mathusianism should be distinguished from neo-Malthusianism, in that the latter does at least have some evidential basis in that it is based on measurement of resource levels and their rate of use, not just some political philosopher's wooly notion of overpopulation.

The problem, as I see it, is that even if you are optimistic about the theoretical capacity of the planet to sustain human life, its practical capacity is limited by how efficiently we use the resources to hand, and the current system does not properly incentivise efficient use. More often, it's the complete opposite, because the price of resources like water and soil does not reflect their true scarcity.

It's like having a large store of firewood. Enough, in theory, to heat your home through several years of harsh winters. Then you burn the whole stockpile in a great bonfire on the first cold Autumn night. That night, by every metric, you'll be warmer and cosier than you ever have been before, but you'll still have doomed yourself.

* * *

Reminds me of the well-known type of question in introductory calculus:

Q: "A population of bacteria in a petri-dish doubles every hour, after 24 hours the petri-dish reaches 100% saturation. At what time did the petri-dish reach 50% saturation?"

A: 23 hours.

What about the birth rate collapse[0] and how this affects things? It’s easy to project out with holding population levels but as the oldest among us die in the next 20-30 years there will be significant drops in population worldwide, before factoring other forms of population decline it’s already naturally going to happen.

I wonder how this factors into all this.

[0]: https://www.economist.com/leaders/2023/06/01/global-fertilit...

population is still rising into 2050 by conservative estimates, and it's not counting the energy requirements per person that's exploding.

on a century scale, we will fix this by either getting to space or having a lower population. but the pressure is going to crack our systems long before that. I'm still hoping we get better as pressure increases, but there's nothing in nature that says that has to be true. the system will correct itself but how we will look as a species on the other side can be vastly different.

Getting to space is not going to happen. We don't have the ability to live sustainably on Antarctica, which is several orders of magnitude easier logistically and technologically.

there is no economy in Antartica besides resource extraction, which is banned. Instead a space economy (logistics, tourism, manufacturing, research) its on the rise. No selfsufficient space colonies in the next 50 years for sure

We still don't have the ability.

Is there any reason to think that the birth rate collapse is a long-term phenomenon (e.g. one thousand years)? There will presumably still be some subcultures that will have high birth rates, and I imagine they will make up an increasingly large proportion of the population as time goes on.

There's a lot of noise about the population decline for 2100, but I wonder about 2200 and beyond.

Education of women is the strongest predictor of falling birth rates - this in turn is unlikely to reverse without a huge change in our economical system.

> What about the birth rate collapse

There are about 8 billion people (about 4 billion more than when I was born) in the world. The "birth rate collapse" isn't making much of a dent in that as far as I know.

Bacteria cannot produce new ways to obtain resources, we can. Quite literally we’ve developed ways to grow food in space. We will be fine.

Lenski.

To be fair the steepest part of the hockey stick is tiny compared to the history of out species. Heck even written texts are a comparitively new invention on that scale. The problem with overshoot is that the situation looks best after the point of sustainablility is long gone. Like flying off a ramp. The peak of heigh comes after you have left it.

You could be right, and there are plenty if examples of that. It is just a case of we wont know the full story until a long time in the future.

Hockey sticks you say, I have an article for you https://dothemath.ucsd.edu/2022/09/death-by-hockey-sticks/.

If we continue our current growth of energy use, we'll be using the entire luminosity output of the milky way galaxy in, drum roll, 1000 years. I'm skeptical if that's going to happen. To me a much likelier option is that the exponential growth stops at some point. The trajectory of the slime mold is also a hockey stick, until it isn't.

Want to know where you can shove your hockey stick?

Stephen Harrod Bruhner once said that society is like of like a plant. It produces its off spring to spread out when it is at its peak health. It makes the biggest fruit just before it dies.

That we started sending intergalactic space probes in the 1970s when, in the west, the energy use per capita was to start to peaking is a funny conincience. Some of those are probably accidentally carrying microbes that will be suspended in state for potentially hundreds of millions of years.

It isnt something to take too seriously but it is a fun concept to contemplate.

Maybe we have the exact same intelligence for logevity as a tomato.

How is this a solar problem? The article clearly states there’s diesel pumps as well that do the same thing.

Cheaper to run constantly.

It's cheaper to extract the water than it used to be.

Diesel has a consumable that must be purchased when the pump is run.

With solar, there's presumably less difference between "run the pump 24/7" and "only run the pump when cost efficient."

It's essentially the same argument in favor of solar power generation. Fossil fuel generation = plant-capital-cost + fuel-per-generated-unit. Solar generation = plant-capital-cost + negligible-wear-per-generated-unit.

The water being pumped is basically a battery.

So it's much more effective than solar is on the normal grid.

Even still, solar has just enabled agriculture on places and on margins that it wasn't viable before. Agriculture itself is also an enabler of the problem, but not the actual problem of the moment. The real problem is how do we, on limited resources, feed a global population that is increasing in size and wealth (and attendant waste)?

Exactly. The problem is the excessive water extraction, not the technology making it cheaper.

Technologies have side effects - some good, some bad. This effect of solar i admit i had not thought about.

It's not a direct effect of solar. It's cheaper energy with undisciplined resource abuse.

It is for the engineering mindset. 'If I build this, what will happen?' is a question you are taught to consider in school and some of the examples are much like this

I totally get where you are coming from. I still disagree though. By definition, a second order effect is not a direct effect since an intervention after the first order effect can mediate second order effects. All the engineers I've had the pleasure to work with care a lot about outcomes to a reasonable level, somewhere closer to the butterfly flapping wings and further from the monsoon it causes.

The direct effect is lower cost of energy. That it gets used to then pump water continuously is a second-order effect.

its an awareness problem in both belief of doing something more environmentally friendly and cost

It is not a solar problem.

It is a Tragedy Of The Commons problem.

Solar just happens to be an enabling technology. Other technologies that brought cheap power to those areas would have done the same thing, e.g., wind or very cheap diesel (biodiesel?) would have the exact same effect if they happened to arrive first. Putting Solar in the headline and as the culprit is a truly cheap shot.

The real problem is that now that power is cheap, it is to everyone's individual advantage TODAY to pump more, but everyone's disadvantage tomorrow when the groundwater reserves run dry. Classic Commons problem, and it's screaming to the inevitable result. The only solution is some way to monitor and regulate the draw from the groundwater.

I wonder what other Tragedy of the Commons enablers lie waiting, undiscovered. (AI maybe in some ways can be one?)

> The only solution

But is it really a problem, from everyone's perspective?

Because, if water is scarce, then, those with money become even more important and wealthy -- they're the only ones who could afford really deep pumps? And now they can sell the water, for more and more money. What's not to like about that?

From the article:

None of this should be seen as a condemnation of solar power, says Balasubramanya. “The fundamental problem is not the solar technology itself.” Whatever the technology, “if the cost of pumping is zero, then people will pump unless some restriction is put on them.”

—

The article also discusses that the panels are much cheaper to run than diesel and are subsidized by agencies and governments while the diesel pumps are not. So, yes, it’s not specifically about solar but about the economics of solar.

In addition to the ways described in sibling responses to this question - diesel pumps suck, solar (submersible) pumps push.

In practice you can't suck more than about 8 metres (in theory it's a bit more), and while there are ways you can force a ground-based pump to get water up from a deeper depth than that .. the economics work against you.

A submersible pump - DC-driven by solar typically - can sit at the bottom of your bore, and push 100 metres or more upwards. No sucking required, so they're relatively simple and efficient.

(My little 75mm x 500mm submersible solar pump, for example, is pushing about 5k litres per day through 600 metres of 50mm pipe, with a vertical (head) of ~40 metres from bore water level.)

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