Is Agriculture Sucking Fresh Water Dry? 379
sciencehabit writes "The average American uses enough water each year to fill an Olympic-sized swimming pool, and global agriculture consumes a whopping 92% of all fresh water used annually. Those are the conclusions of the most comprehensive analysis to date of global water use, which also finds that one-fifth of humankind's water consumption flows across international borders as 'virtual water' — the water needed to produce a commodity, such as meat or electronics, if the ultimate consumers were to make it themselves rather than outsource its growth or manufacture."
Solution (Score:5, Informative)
if the ultimate consumers were to make it themselves rather than outsource its growth or manufacture.
There are some good solutions in The Humanure Handbook [humanurehandbook.com]. That does not change corporate agriculture, but a little awareness on our behaviour is a good thing.
As Mark Boyle (The Moneyless Man) once said: if we knew how hard it was to purify our drinking water, we sure as hell wouldn't shit in it.
Re:The real questions should be different (Score:5, Informative)
It's true that we can use much less water in growing our food but it's not easily done. More to the point it's not done cheaply and that's the biggest issue. So long as it adds to the cost of food (even if it's only pennies to a pound of tomatoes) there's going to be an issue with getting the majority of farmers to change their practices. Especially in third world countries where getting those improved practices out to the farmers can prove difficult.
It's certainly a worth while thing if an area is experiencing a lack of rainfall (as in much of Africa) or if their aquifer is beginning to run low (apparently an issue in some areas of the Outback in Australia) but without some incentive it's going to be difficult to get people to change.
Re:The real questions should be different (Score:5, Informative)
Here's a novel idea - you could try not feeding corn to cows. They can't eat it anyway, so it's a collossal waste of resources.
Here's a hint - most of the world's farmland isn't rolling midwestern cornfields. Most of the world manages to raise livestock just fine.
Partly it's a question of preference - Americans like bland greasy meat, so their livestock farming practices reflect that.
It's all to do with pricing (Score:5, Informative)
The perception is that when something is cheap, it is of low value so it doesn't matter if you consume too much of it.
If you look at areas where water is scarce and where wars are fought over it, or where it has to be desalinated i,e, it's expensive, you'll find the users are a lot more careful over how much is used and how it is used.
Compare US irrigation methods:
http://en.wikipedia.org/wiki/File:Irrigation1.jpg [wikipedia.org]
with Persian Qanat methods:
http://en.wikipedia.org/wiki/Qanat [wikipedia.org]
Re:We see this all the time in the western US (Score:4, Informative)
The other problem in Australia is the ~variability~ of the supply of water. When it's dry, you really need that extra infrastructure ... but most of the time it'll sit there being relatively unused.
It's not true that the east has lots of water. Generally it either has too much, or not enough. "Not enough" is far more common than "too much". Right now it's wet: two consecutive La Nina summers with consequent flooding and heavy rains. Dams are all basically full. Crop yields are up (at least, in the areas where they aren't under 6 feet of water!)
However just a couple of years ago we were at the tail end of an almost decade-long drought. Worst in a century they say. Many towns completely ran out of water and had to have it trucked in daily (reasonable sized towns too, like Goulburn NSW). And even in the large capital cities things were looking grim ... here in Canberra our dams were only ~20% full at one point. For a couple of years, we were on the highest level of water restrictions that existed - no watering of gardens/lawns/washing of cars/filling of pools permitted, and minimal water allowed for personal use. Similar stories in Sydney and Melbourne. And when a drought is so, so long, you begin to think it will never rain again and the seemingly absurd prospect of a major city with millions of people literally running out of water starts to look increasingly likely (scary!)
Sydney built an expensive desalination plant in response to this threat. Canberra's building another dam (or technically, they are massively expanding one of the existing 4 dams that feed the city). Of course, as soon as these projects got underway, the rains started falling properly again for the first time in 9 years. The desal plant sits basically idle now (since Sydney dams are back to almost 100%) Still, I'm sure it'll be needed one day so I don't see it as wasted expenditure.
You're absolutely right that huge volumes of water flow into the ocean in Eastern Australia that could be tapped to provide for the cities. Generally this is of a 'quick and heavy' nature (thunderstorm runoff). So in the long term I think the cities are OK. The big problem is that most of our agricultural areas are inland of the Great Dividing Range, so water that falls there flows inland into the Murray Darling basin. And rainfall out that way is very erratic ... and even in good years, it's not that high. Australia is a very dry continent once you're off the narrow coastal fringe between the east coast and the Divide (only 50-100km wide for the most part). No amount of dams will help the inland because the rain simply doesn't fall often enough. You'd have to divert water from the coasts (which is essentially what the Snowy Hydro Scheme [wikipedia.org] was about (and is largely what allowed cultivation of the inland to occur in the first place). But I don't think there's the appetite these days for such massive and expensive infrastructure projects to be honest.
Also as far as I know, Australia still exports far, far more food than it imports. I'm sure I've read recent figures showing we produce 4-5x what we need to be self-sufficient ... so I don't think we are reliant at all on imported food. We might ~choose~ to import some food rather than grow our own, but if worst comes to worst and we suddenly were completely isolated from the rest of the world, we'd be fine.
Re:The real questions should be different (Score:5, Informative)
Re:The real questions should be different (Score:5, Informative)
Indeed ... 'corn fed' meat is not the norm in most of the world. Here in Australia it's almost all grass-fed. Then again, we don't have the harsh winters that necessitate keeping cattle indoors for several months each year, so it's easier just to let em roam free and munch on the grass all year.
Incidentally, I honestly don't know why Americans prefer corn-fed meat. It seems fattier than grass-fed and doesn't taste 'right' to me, but I suppose that's simply because I grew up eating 'our' meat and got used to that taste. As you say, a preference thing.
Actually no (Score:4, Informative)
With the passing of time, local crops have dwindled due to inter regional trade, and supply demand constraints. For example, in arid regions of India, instead of wheat "Jowar, Bajra, Ragi...." etc., were grown which use much less water. but since majority eat wheat, in the interest of business, farmers shifted to Wheat, which uses more water. In other regions, which never grew rice(due to lack of water), canals saw increase in rice production, and movement of local populace to wheat and rice, instead of the local cereals which consume less water.
So everybody does not need to eat rice. Rice and wheat users can have other cereals added to their diets, and increase demand, and some cultivation area can be reclaimed, and balance restored.
Another aspect is hybrids. Many high yield varieties(which in the long run are not all that more beneficial) often require higher water content. In irrigated regions, people often switch to those varieties. In the short run you have better profits, but since these are not as resistant to local conditions(in some cases), it also means increased pesticide expense.
So with intelligent Farming, and growing crops actually suited to the region, water usage can be minimized.
Apart from that, there is the irrigation question. Using drip irrigation drops water usage by over 60-70%. We have used it on an piece of land where irrigated water was a scarcity, and illegal mining killed local rivulets and creeks. Due to very less quantity of ground water, and only perennial source being an artesian well, we had two options, stop growing, or use wisely. thanks to some govt subsidies and support, we were able to setup a drip irrigation system, which resulted in low water usage, and now we have surplus water.
Unfortunately, much of agriculture, even in developed world, does not move to this kind of savings unless there is a sword hanging on the head. Countries like Israel have water shortage, so they have moved to intelligent use. If other places where shortage is not there yet, also move, it will result in water saving.
Lastly, in many areas, rain water is not stored effectively, and a lot goes waste(flows into the sea). If a large part of that can be channeled to groundwater using recharge zones, it will replenish groundwater which can actually help people survive a year or 2 of dry season.
That said, other than conservation, many places can also have strict policies to block untreated industrial waste flowing into rivers, which will result in higher fresh water availability
Definitions - Tricky Things (Score:5, Informative)
This study borders on sleight-of-hand to my mind. At least the way it is presented is misleading.
The headline says that 92% of freshwater use is in agriculture. What it doesn't mention is that the vast majority of that "use" of water is rain that happens to fall on farmland. We could increase that number by converting land use to arable land without changing any natural flow of water. For instance, the city of Adelaide is about the same area as the county of Cornwall and is built largely on prime agricultural land. Moving the city 100 miles North East onto unfarmable land and resuming agriculture there would noticeably increase the agricultural use of water - but it would actually be an environmentally good thing.
When it comes to diverting the natural course of water (extraction from rivers, building dams, draining lakes etc - what you might call exploiting the natural resource), the use of water in agriculture is much less - the majority here supplies water for urban residences and industry.
A direct link to the pdf (Score:3, Informative)
This is a better link.
http://www.pnas.org/content/early/2012/02/06/1109936109.full.pdf
Want To Use Less Water? Do Meatless Mondays (Score:4, Informative)
Re:The real questions should be different (Score:4, Informative)
The problem is most water on the planet is full of salt. You can't use salt-laden "grey water" to grow things.
What year is it? [wired.com]
See also AIWPS [sdsu.edu].
Basically, at the point where you might consider it on a large scale, it's generally just easier to use fresh or drinking quality recycled water.
Easier is not the issue here, sustainability is. There's no question that if you continually pump more from aquifers than goes in you will have problems.
Re:The real questions should be different (Score:2, Informative)
WTF???? Feeding the trolls....
"They can't eat it anyway, so it's a collossal waste of resources."
Citation? Because I have 300 dairy cows out back that will call you a lier. BTW, you don't feed cows, you feed there rumen bugs, which then feed the cow.
Re:The real questions should be different (Score:2, Informative)
I honestly don't know why Americans prefer corn-fed meat
They don't. They just don't know any better.
FYI, the US government has subsidized the corn industry (i.e. they take money from other people, by force, and hand it over to the corn industry, like some kind of mafia scheme). This has allowed the corn industry to become a dominant force that would never have occurred in a free market. You will find corn sneaking into foods you would never have thought: ice cream for example (corn syrup, being subsidized, is artificially cheaper than real sugar). The situation is ridiculous -- and reeks of injustice -- but as you are probably aware, there is no such thing as a temporary government program.
The people behind it are making millions; that was, of course, the entire point.
Re:It's all to do with pricing (Score:5, Informative)
The nozzles on these machines vary in size from the center (i.e. near the pivot) to the end. Think about it: The drops near the pivot go around the circle much more slowly than those on the end, and so if the nozzles were all the same size, a lot more water would be put out near the center. Also, the water pressure is higher there since it hasn't undergone friction losses through the length of the sprinkler. During the first summer that my dad owned that machine, I remember walking down it several times with a dot matrix print out in one hand and a bucket of nozzles in the other, replacing them one at a time to try to evenly distribute the supply of water as much as possible.
A half-mile-long sprinkler was (again, 20 years ago) an $80K investment over the former, low-tech system of row irrigation, and he was and is not an especially wealthy farmer. Why would he go to so much expense and trouble? In part because one of his largest expenses is pumping costs, and center pivot irrigation makes much more efficient use of water, overall.
2. I am not personally familiar with Qanats, but they appear to be a water collection and storage method, not a method of irrigation. It was surprising difficult to find quantitative information about irrigation in the middle east, but after several minutes of googling, I did find this brief, UN-produced report on irrigation in Saudi Arabia. [fao.org] It claims, in part:
All agriculture is irrigated and in 1992 the water managed area was estimated at about 1.6 million ha, all equipped for full/partial control irrigation. Surface irrigation [i.e. row watering, like my dad used to do] is practiced on the old agricultural lands, cultivated since before 1975, which represent about 34% of the irrigated area (Figure 3). Sprinkler irrigation is practiced on about 64% of the irrigated areas. The central pivot sprinkler system covers practically all the lands cropped with cereals.
Oh.
Re:The real questions should be different (Score:4, Informative)
So while it's easy to blame meat, vegetable growers are just as guilty. If meat is evil, vegetables aren't far behind.
Alas, no. You get a lot more available food calories per gallon of water when growing vegetables (the exact amount depends on the crop; there is substantial variation) than when raising animals, with cows being particularly demanding. The trick to raising animals efficiently is to feed them on things that people can't eat (e.g., grass) as there's a lot of places where you can't use high-efficiency food crops because of environmental conditions. (In my part of the world, sheep work well because they tolerate the climate and rough-grazing available. Wheat would just rot in the ground before harvest.)
Re:The real questions should be different (Score:4, Informative)
Not sure if that was a typo, but the researchers came to the opposite conclusion.
From the first article:
His grammar was confusing, but that's what he meant. To summarize: grass fed good (and tastier), grain fed bad.
Re:There is an easy way to help (Score:3, Informative)
Water management comes down to, if you want more water available to use you need to have swamps, the natural way for the land to store (and clean) water without evaporative loses or unfairly keeping water from your neighbors. Ironically they are the very thing farmers have been doing their best to get rid of.
To sum up, land with swamps = good for the land, good for the water, good for the water table, bad for large mechanized efficient farming.
This has been my opinion on the matter taken from, talking with people employed by the environment ministry, research (google), talking with other farmers, and experience on my own farm.