This thread is dedicated to FR, who said we have plenty of fresh water. Yeah right... http://www.eeo.com.cn/ens/Observer/2008/02/29/92990.html "China's massive but dwindling aquifers would be on track to run virtually dry if over-pumping continued, said Lester Brown, prominent US environmental policy advocate. At that point, its grain production would dive, severely exacerbating any food price increases that had already accumulated. Without rationally priced water, Brown predicted this scenario and a severe global food shortages as inevitable."
How much stored water has been pumped out of aquifers world-wide, and how many millimeters in ocean-level rise would this account for?
I don't think those 2 are related or not that closely. The oceanlevel rise is related to the ice melting....
I didn't say that it was distributed evenly, any more than food is. I simply said that the supply of fresh water on this planet is more than enough for the people as well as other important uses like sustaining the rainforest. The point is that during an ice age a huge portion of the earth's water is trapped in polar ice, where it is quite difficult to extract. Rainfall diminishes dramatically during an ice age, there are droughts everywhere, and large sections of the earth's land mass turn to desert. That's what I mean by "not enough fresh water." The cost of extracting water from polar ice is, I'd estimate, at least one order of magnitude higher than anything we now face. I wouldn't be surprised if desalinization of seawater would be more practical, and we know what a marginally cost-effective technology that is. Aqueducts can be built to take water from places where it's abundant to places where it's not. Sure that costs a lot of money and that's why many of us are investing in water technology companies. There are lots of other ways too. Where we live in northwestern California the rivers dump cubic acres of freshwater into the sea. All you have to do is park a barge there with a gigantic bag and collect it as it runs out, then sail down to a place like Los Angeles where water is precious and pump it out. This takes advantage of the clockwise current in the northern ocean of course, the voyage won't use much fuel. Still it's just a matter of expense to take it somewhere else. Much water in the Third World and even in the Two-And-A-Half'th World like China is lost by allowing wastewater to flow into places where it isn't even beneficial, like rivers and seas. The watercone solves that problem. Individuals and families can recycle the water out of their own sewage, much less their laundry and irrigation runoff. I'm not saying that distributing the adequate freshwater supply that exists in today's climate can be done without a little technology and a lot of process-improvement in most of the big governments. I'm just saying that it can be done without bankrupting global civilization. There's plenty of technology to solve China's problem and plenty of water for them to tap when they decide to do it. It's just a matter of money and China has been accumulating quite a bit of that lately. China's problem is that its government is incredibly short-sighted--it makes Bush look like a visionary. They're sitting around watching their air turn to sludge and the Gobi Desert visibly expanding toward the Beijing suburbs. And they've got the double-whammy problem of a Confucian culture that generally accepts the wisdom of its elders without analysis or controversy. China's problems of energy, pollution and water are going to have to reach truly crisis proportions before anybody over there becomes willing to do anything about it. That's the real problem we face, not water per se. Taking water out of aquifers, using it, and dumping the resulting wastewater into rivers which ultimately flow into the ocean, can't help but raise the sea level. That's just basic arithmetic. The question is whether it would be a significant factor compared to the current climatological trend. I can't answer that question.
But that's what it comes down to. Atlanta is not helped if there is plenty of rain in Seattle. To transfer water in large quantities for long distance is not economical and soon enough we will run out of the energy to do so anyway. Drinking water from Fiji!!! I still can't believe it. Theoretically, maybe, practically, no. As the article stated China (1/6th of the Earth population) might soon enough run out of water. And here in the US we already have pretty decent waterproblems. So it is rather IRRELEVANT if there is plenty of water in the polar cap, if the crops are dying in Kansas.... It probably is. Some of the Arab states are getting their water from desalization. OK, that is dreaming. They haven't been built for a reason, so I am not really expecting to happen this anytime soon. Interesting that civil engineers haven't thought of this. I don't know much about it, it looks like a solution only on the family level, not industrial applications... And I predict it will be too late. Goverments usually act a few steps behind. The polution is already incredible in big Chinese cities. I thought of that but so far nobody brought this up when discussing the ocean's rising, so I take it isn't that signifficant. The problem is that this water once reaching the oceans stop being freshwater....
We pump water about 300 miles in California by aqueduct. It's expensive but it's practical. There's no reason it couldn't be done over longer distances. No, not in the polar caps. As I said, that would probably require too much energy. One thing they have toyed with is towing icebergs. As a matter of fact they did. They had the project all ready to launch a couple of years ago, investors and everything. It's a piece of cake because it is just incredibly low-tech. But they couldn't get a permit to deliver it to Los Angeles because the company that sells the water from the aqueduct has a lot of political influence and they still have to repay all the bonds they had to sell to build it. Barge-towed water is cheaper than aqueduct water if you live near the ocean! Yes of course it is, but that's what they need in the Third World. Children are dying of dysentery because they can't get clean water. The watercone provides it, it's basically a personal solar still. Industries have investors and managers and accountants, they can pay for their frelling water. That's exactly it. I'm sure the impact on sea level is insignificant compared to the melting icecaps. But the dissipation of aquifers due to inefficient water management is a significant societal problem, even if not an ecological one.
Hard to say. One cant dismiss the relationship between evaporation via irrigation and its contribution to rain clouds and water runoff further downwind. I dont know that any cause effect relationship has been established. But heres the wiki on the oglala aquifer: http://en.wikipedia.org/wiki/Ogallala_Aquifer
This is a 5 year old article on the topic: http://news.bbc.co.uk/1/hi/sci/tech/2943946.stm Ths most interesting data is that 70% of the waterusage goes to agriculture, 22% industrial and only 8% is domestic. Another good info website on general water Q and A: http://ga.water.usgs.gov/edu/wateruse.html I think the oceanlevels don't rise at all because of taking water out of the aquafiers, because it is part of the watercycle...
If the aquifers are running dry, the water cycle is obviously out of wack. All that water that used to be underground is now above ground and ends up in the ocean
Out of whack, yes, but eventually the drought ends and the water ends up back in the ground... So in the long run, the oceanlevels don't rise...
A nice thought. Don't try telling that to the people who rely on the aquifers that are drying up, though. They won't believe you.
Couldn't you say the same for melting the icecaps? Eventually, they'll freeze again. So there's no real change?
Palaeowater, which has been untouched for more than centuries, is one of the fastest disappearing resources that we exploit. In India, the Sinai, China, the US, Australia, and a lot of other places. Not centuries, but tens of thousands of years (hundreds of centuries), is the replacement timescale. The falling water table and resultant increase in desertification will no doubt mean a lot less habitation in the future (like, when all the water has gone). A re-freeze, if the poles are melting, will require the climate to flip over into ice-age mode. Until another ice-age, the poles will keep melting. We don't think far enough ahead in general, to stop using something until it's depleted.
The difference is the timeframe. The iceage cycle takes a couple of thousands years compared to the few years drought cycle...
