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Thread ID: 99144	2009-04-21 23:36:00	A Bit of Depression for the week	pctek (84)	PC World Chat

Post ID	Timestamp	Content	User
767120	2009-04-21 23:36:00	www.newscientist.com because www.peterrussell.com	pctek (84)
767121	2009-04-22 01:55:00	This is bullshit. They say "Figures do not take into account changes in demand due to new technologies". Well they also don't take into account changes in supply due to new technology. The limits they use are not actual geologic amounts; they only represent high-grade ores in all cases, which are an insignificant fraction of what is available in the earth's crust. A more accurate label would be "how many years left... at exactly the same price as today". Let's see: aluminum - only a thousand years' supply? This sets off my bullshit alarm: the earth's crust is 8% aluminum - it's the most abundant metal in the crust (note silicon is not a metal, and iron is less prevalent in the crust than in lower layers). en.wikipedia.org 60% of all rocks are feldspars, minerals of aluminum: en.wikipedia.org So how the hell do they get only 1,000 years from this? Apparently, they only look at the one ore which is currently used for aluminum - bauxite - and ignore everything else, as if it didn't exist. When they say "supply of aluminum", they must mean "supply of bauxite". And that's completely dishonest, or stupid, or probably both. Although aluminium is an extremely common and widespread element, the common aluminium minerals are not economic sources of the metal. (empasis mine - demre) Almost all metallic aluminium is produced from the ore bauxite (AlOx(OH)3-2x). Bauxite occurs as a weathering product of low iron and silica bedrock in tropical climatic conditions.[9] Large deposits of bauxite occur in Australia, Brazil, Guinea and Jamaica but the primary mining areas for the ore are in Ghana, Indonesia, Jamaica, Russia and Surinam.[10] Smelting of the ore mainly occurs in Australia, Brazil, Canada, Norway, Russia and the United States. en.wikipedia.org True, it would be more energy-intensive - and expensive - to extract aluminum from feldspars, but at such a higher price, the supply is effectively unlimited. You'd literally have to strip the earth's crust off of its glowing-hot mantle before you'd worry about aluminum shortages (...not that I recommend this. And see the last paragraph in this comment.) Another thing: trace elements can be extracted from the ocean, where there is millions of times larger reserves than all conceivable mining reserves put together. They are quite dilute, so this requires highly selective chemical absorbents. But this not very far off, and could very soon be economical for some elements (trace elements which already have very high prices per gram): www.taka.jaea.go.jp Another thing that pisses me off: for uranium, their consumption figures are bullshit. Less than 1% of uranium is converted in nuclear reactors (the U-235, and a small fraction of U-238 converted to Pu-239); the remaining 99% U-238 - viable fuel for alternative types of reactors - is buried back in the ground, either as the depleted uranium from enrichment, or as part of 'spent' reactor fuel. The actual 'consumption' of uranium in their graph is exaggerated by a hundred times. One last thing. With the exception of nuclear fuels (which are transmuted into different elements), none of these elements are ever 'consumed": they rarely leave the planet. All that humans do is bring up metals from rocks, do some stuff with them, then put them back underground in heterogeneous landfills of resources. Already, in third-world countries, people are diving into dumpsters for precious metals (and at great health hazard, unfortunately). So a billion years from now, when a realistic extrapolation says we'd be worrying about aluminum, we wouldn't be pulverizing the earth's crust 100 miles deep: we'd simply be sending mining robots into the landfills (probably 1-10% aluminum by mass (?)), recovering anything that's not being used. We couldn't face a real aluminum shortage unless we were simultaneously using every gram of aluminum in the earths crust, which would be pretty obscene - imagine solid aluminum skyscrapers 1,000 miles high covering inch of land. That's not even physically possible AFAIK - the bottom layers would liquefy from the pressure above them. Unless they were transparent..	roddy_boy (4115)
767122	2009-04-22 05:10:00	The staggering rate of the increasing human population is scary.... Just imagine. With only 6.7 billion people today, look at all the chaos that's going on. Just imagine what it would be like in just 15 years with over 7.7 billion.....	qazwsxokmijn (102)
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