I Googled in "desalinization" and hit Wikapedia which had a nice overview of the subject. Virtually every sub-topic, though, carried a "warning label" about more links, citations etc being required.
@realjohnboy,
realjohnboy wrote:
I Googled in "desalinization" and hit Wikapedia which had a nice overview of the subject. Virtually every sub-topic, though, carried a "warning label" about more links, citations etc being required.
Desalination can be energy intensive, the use of membrane technologies can reduce this somewhat.
Introduction to Desalination technologies in Australia
http://www.environment.gov.au/water/publications/urban/pubs/desalination-summary.pdf
reclaimed salt is generally pumped out to sea and allowed to reintergrate. There needs to be some study done to choose the right location for the ocean outfall to determine currents etc that will not allow salt levels to accumulate.
It is relatively easy for people in the United States and Canada to be casual, and through inattention, to be cavalier about water. The Great Lakes contain more than 20% of all the fresh surface water on the planet. An attempt in the late 90s to ship about 160,000,000 U.S. standard gallons of water annually from the Great Lakes to Asian nations was squashed due to public protests. The states and provinces which border the Great Lakes have made agreements which prevent water diversion, and prohibit the exportation of water from those sources, except between Canada and the United States. Most water use issues in the United States which are crucial result not from how much water is available, but from where people live. It's difficult to provide Los Angeles, for example with the water it needs, let alone what it wants. But if world population growth continues at a significant pace, where people get their water is going to seem a small consideration in the face of the fact that we have at least enough, and without expensive alternatives such as desalinization, in view of how critical the situation will be for other nations.
Thames Water used to run charitable projects to provide clean drinking water for people in the "third world," but i don't know if they still do--they're a privately-owned corporation, and they've had troubles of their own in recent years with the agency which oversees water use in the UK. The "Great Lakes" of Africa represent a fresh water resource almost as extensive as the North American Great Lakes. However, this "Great Lakes" region covers several nations, and almost all of them have been subject to civil strife, civil wars and repressive regimes. The people of that region live in poverty, and it is doubtful that those nations will have the financial resources to manage the water well and intelligently, and there is no good reason to think that they will share graciously with other nations. There is no comparable region of fresh water resources in Eurasia, and most of the deep lakes of Eurasia lie within the borders of the Russian Federation. Europe, for now, does manage its water resources effectively.
I also mentioned agriculture. The recent shortage of rice, and its rapid and widespread effect ought to be a minatory tale for us. Once again, North America is not badly off because if its agricultural resources. In that respect though, in a future in which North America is not literally on a military defensive because it can eat while the rest of the world cannot reliably feed itself, plans like Cyclo's would be more and more attractive as an alternative to suburban sprawl, the only real point of which is to line the pockets of developers and real estate speculators, while voraciously eating up huge tracts of valuable farm land. These speculators and developers sell their new "dream" communities at the expense of inner city neighborhoods, which cannot be used to replace the farm land lost.
Cities such as Cyclo envisions for the future stand on the edge of a knife. For all their desirability for a great many reasons, the need for them is actually greatest in the places with the least resource to build them. The political and tribal divisions of nations will interfere with any utopian projects to deal with population growth. When i was a child, the population of the planet was under two billion, and it was thought then that we faced eminent disaster. Now we have more than six billion, and it is getting harder and harder to meet the demands for food and water simply through new technology and economies of scale in use. The biggest problems will be in dealing with nationalism and ideology. If desalinization begins to threaten the ocean ecosystem with the salt removed being dumped back in, who is to tell thirsty nations they can't do it, no matter what their needs are?
