Per chi si interessa di picco del petrolio da un pezzo, sono tutte cose risapute, ma è comunque interessante vedere come la storia si stia diffondendo sempre di più. Notare anche come citi il "Picco dell'Uranio" subito nel primo paragrafo; anche questa è una storia che si sta diffondendo sempre di più.
Originale a:
http://service.spiegel.de/cache/international/spiegel/0,1518,426728,00.html
HOW MUCH LONGER?
The End of the Oil Era Looms
By Alexander Jung
Oil, uranium, gold and platinum are more sought after than ever today. The search for natural resources is becoming increasingly difficult and prices are soaring. But future growth of the world economy depends on these natural resources -- and some will soon disappear forever.
He was urged not to present his forecast, Hubbert later revealed. But the scientist with his little Clark-Gable-style beard stuck to his guns, as he has often been known to do. When he appeared at the spring 1956 meeting of the American Petroleum Institute in San Antonio, he presented exactly what he had prepared -- a theory as simple as its implications are dramatic.
Hubbert claimed that the exploitation of oil resources always follows the pattern of a bell curve: first it rises, then it flattens out, and finally it declines -- irreversibly. According to his calculations, the United States would soon reach the peak of the curve -- around about 1970, according to his estimate.
His prediction could hardly have been more accurate: In fact, it was in 1971 that the US's oil extraction reached its maximum level. Ever since then, oil production in the US has declined.
Hubbert's curve was discovered exactly 50 years ago and is still considered part of the basic knowledge of every geologist. The rise and fall of the curve presents a scientifically precise description of something everyone knows, just as everyone wants to deny it. Petroleum is a finite resource. The supply shrinks every day, every hour, every minute. Once the supply is used up, it's gone for good.
Other important energy sources -- natural gas, coal and uranium -- are subject to the same relentless process. They are constantly consumed, but never replaced.
The supply of metals and minerals isn't unlimited either, just as it isn't replaceable. Iron ore doesn't reproduce itself, and neither does gold -- none of these resources replace themselves. But how many people really think about how unique these resources are?
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Human beings have made use of natural resources since prehistoric times. They produce tools from iron and copper, heat their living quarters with coal and natural waste, build houses from sand, plaster and stone. But it was only industrialization that caused demand to increase dramatically -- trade in metals, minerals and fuels became a global business phenomenon. Humanity has consumed more resources since the end of the Second World War than during its entire previous history.
Now China has entered the international market -- a country with an unusually rich supply of natural resources. But it consumes even more than it has, as the price changes of recent years reveal: gold now costs almost twice as much as it did four years ago, and platinum is more expensive than it has ever been. Even junk metal has now become a good source of revenue.
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It's only since the "classic" resources have become so expensive that people are becoming aware of their importance again. No computer chip can be produced without silicon, no plastic product without petroleum, no catalytic converter without platinum or palladium. Digital technology and the information economy are both well and good -- but the economy still fundamentally depends on steel and cement, and it's driven by oil, gas and coal. But for how much longer?
The future of many industries depends on the answer to this question, as does the development of the world economy itself. Rising prices are usually an indicator that a commodity is growing scarce and that demand for it is rising. So does the rise of resource prices mean that supplies are running out? And if the answer is yes, then how much time remains before the supply will run out?
If the predictions made by Dennis Meadows in his 1972 report for the Club of Rome think tank had been correct, then humanity ought to have reached the limits of growth by now. Meadows was a young scientist at the time, not yet 30. He and his colleagues at the Massachusetts Institute of Technology fed a supercomputer with vast amounts of data. The results shocked the world.
Then there are the notorious optimists. They claim that the world's resources are still far from exhausted and that enormous reserves still exist -- around the North Pole, for example. What's more, they argue, industry has always succeeded in extracting more than expected thanks to innovative methods.
The calculation presented by these optimists is simple. They divide the quantity of known resources by the annual consumption of resources. According to this calculation, conventional petroleum will last another 40 years. Natural gas will last for more than 60 years, and coal will last for a full two centuries.
The figures sound reassuring. The only thing strange about them is that they've hardly changed during the past 50 years.
The reason is that the calculation has more to do with economic logic than with geology. When the price of gold rises, the extraction of smaller or less easily accessed deposits becomes profitable. Resource deposits that were previously ignored suddenly enter into the calculation and the quantity of resources automatically rises.There is another variable in the calculation: New technologies such as those of multidimensional seismology, which allow for locating even small pockets of petroleum or minor ore deposits, and changes in consumer habits. For example, the demand for copper has declined substantially in the field of transmission technology, since copper has largely been replaced by fiber glass. Now the demand for quartz is declining, because fiber glass technology is being displaced by satellite technology. Such unpredictable influences strongly qualify the validity of the consumption-supply relation; the formula is inadequate as an instrument for predicting future developments.
And yet there are serious answers to the central question: "How much longer?" They aren't easy or simple answers - they vary from one resource to another -- and they are far from conclusive. How long a resource will last isn't decided by fate. It depends on human action.
The most reliable predictions are those about petroleum supplies -- thanks to the discoveries of geologist Hubbert. The picture that is emerging is worrying even to the sober-minded observers at Germany's Federal Institute for Geosciences and Natural Resources (BGR), which is based in Hanover. "We're closer to the peak of resource extraction than we would like," warns geologists Peter Gerling, an expert on fossil fuels.
The so-called "depletion mid-point" will be reached within the next 10 to 20 years, according to Gerling's most recent study. The depletion mid-point is the point at which half of the total quantity of petroleum has been used up.
Gerling is confident the results of his research are accurate. "The Earth has been explored in detail," he says, adding that the layer of the planet's crust that contains its roughly 600 petroleum sediments is known in some detail: "There won't be any major surprises." Gerling's matter-of-fact statement has dramatic implications. Once the depletion mid-point has been reached, the end of the petroleum age will begin.
From that point on, when global resource extraction reaches its maximum, a physical supply gap opens up for the first time in history. From then on, petroleum production declines, whereas demand is likely to continue to rise. There's no return to yesterday's heights, and what's worse: The peak is reached without warning.
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