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Satellites reveal widespread decline in global lake water storage

science.org

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Re: Satellites reveal widespread decline in global lake water storage

#71

Post by dahart »

paiute wrote: post #33
fahadkhan wrote: post #21

Earlier quoted context omitted.

Probably because it's ignoring the start of very next sentence in an attempt at sarcastic wit. > The net volume loss in natural lakes...

... then they start talking about km^2 of lost surface area. Which if you read the paper they cite, it says "Between 1984 and 2015 permanent surface water has disappeared from an area of almost 90,000 square kilometres, roughly equivalent to that of Lake Superior, though new permanent bodies of surface water covering 184,000 square kilometres have formed elsewhere." On top of that, shallow lakes fluctuate wildly in s…

Yes of course the relationship between volume and area depends on the lake depth, are you suggesting the paper implied anything else? The Great Salt Lake has dropped rather dramatically in the last ten years, so much so that it has already changed pretty much all recreation and commercial activity on the lake - the primary boat dock closed because the marina was completely dry and by last year the shores had moved inward, by kilometers in some cases. Unusual precipitation this year has brought levels up a little, but this might only be a blip in the downward trend. The known reasons include drought conditions, unusually high temperatures, and greater upstream use. The Great Salt Lake’s recent history very much backs up the claims of this paper, no?

Re: Satellites reveal widespread decline in global lake water storage

#73

Post by bombcar »

XorNot wrote: post #40
HPsquared wrote: post #31

Earlier quoted context omitted.

Not staggeringly expensive, about 38 cents per day per person, apparently: https://en.m.wikipedia.org/wiki/Desalination#Costs Although that doesn't include irrigation.. EDIT: can even be economical for irrigation in some circumstances: https://www.fluencecorp.com/desalination-and-agriculture-les...

Kind of leaving out the main point there. People don't use a lot of water. Industry and Farming do. We depend on both of those for...pretty much our entire society.

People use water directly and indirectly. And water is "used" and "used" - it's not as simple as measuring a pipe, you need to know where it goes.

Re: Satellites reveal widespread decline in global lake water storage

#74

Post by dghlsakjg »

makz wrote: post #28

Dumb question: where did the water go?

I think it’s pretty likely that the main cause is it’s being diverted for agricultural use.

Things like diversions into cities will also contribute, but generally gets dwarfed by agricultural use.

The Colorado river flow for example is 80% agricultural. 20% for all other uses, including the bare trickle that actually makes it to the ocean

Re: Satellites reveal widespread decline in global lake water storage

#75

Post by TeMPOraL »

dghlsakjg wrote: post #70
piyh wrote: post #61

Earlier quoted context omitted.

Put them down stream of farm runoff so everything is already dead

Farm runoff normally has the opposite effect, providing too many nutrients causing things like algal blooms.

So the brine and the farm runoff will cancel out and the result will be just right for nature. Right? Right?

Re: Satellites reveal widespread decline in global lake water storage

#77

Post by mynameisvlad »

1234letshaveatw wrote: post #66
mynameisvlad wrote: post #46

Earlier quoted context omitted.

And most of that rain is going to go into the ocean again. Or be distributed in a large area. Neither of which can really be captured in any sort of predictable and scalable manner. You know, unless we build a massive “roof” of devices to capture all that rain. Literally covering the entire planet. At that point yeah it would dev a reasonable thing to bring up in the context of fresh water reserves falling. So I very…

The rain can be captured by farms.

> in any sort of predictable and scalable manner.

How?

Rain is not predictable at the scale of a crop season. Rain is not scalable, it’s extremely localized.

Rain happens, and when it does your crops get watered, but you can’t in any way shape or form rely on that.

Re: Satellites reveal widespread decline in global lake water storage

#78

Post by dghlsakjg »

phpisthebest wrote: post #17
XorNot wrote: post #14

Earlier quoted context omitted.

Into the ocean. The ocean covers the majority of the Earth's surface. The ocean is full of salt. Water which rains out over the oceans is unusable as drinking or irrigation water without expensive processing (desalination). If historic rainfall patterns change, there is absolutely no requirement that the rain land anywhere useful for our existing infrastructure or human habitation. Yes, the water won't disappear, but…

>>it's that is is staggeringly expensive to do so. Necessity is the mother of all invention, and with Necessity also comes scale, and with scale comes less cost... Desalination has been expensive because it is not necessary, the second it becomes necessary I bet you will see the costs drop.. If nestle had to use Sea water to fill their bottles I bet they would have a cheap way to do it right quick

There’s the rules of physics to consider.

There are more than a few places where desalination is necessary, and we still haven’t come up with a way to make it cheap.

The current issue is that there is just no way that we know of to reliably desalinate that isn’t super energy intensive, so it comes down to trading energy for water. That’s why desalination is expensive.

Re: Satellites reveal widespread decline in global lake water storage

#80

Post by SkyPuncher »

smeej wrote: post #6
eimrine wrote: post #4

Earlier quoted context omitted.

> Earth is a closed system, so we should expect to see water storage decline in some areas and flooding increase in some areas. Of course, Earth is a closed system, but I am not sure it is that closed.

I don't mean this to sound snarky. I'm genuinely curious where you think the water will go, if not to other places on earth.

The earth as a whole is roughly a closed system, but "usable water" is not.

Most resource problems are not about the quantity of some thing changing as a percentage of earth's matter. Most resources are about density and composition.

If all of the (non-ice) freshwater on earth was suddenly dumped into the ocean, we'd have the same amount of overall water - but little to no drinkable water.

Likewise, we're not really creating new carbon by burning fossil fuels. We're moving and re-distributing it. Compared to being deep underground, the form we create by burning captures much more heat, causing many problems.

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