"... has noted that a considerable percentage of the energy recovered from these alternative sources is expended in their processing--two barrels out of every three in the case of tar sands and a similarly low net energy recovery for heavy oil".

two letters and an article on oil (all peer review and short)-
-there ain't any; it's too many people, in general, and the selling to the world (consumerism) of clearly superior 'American free-enterprise, capitalist democracy and the right to make as much money as you can and spend it any way you choose'

perryb

July 1, 2005 Science Magazine
Letters
When Will the Oil Run Out?

In his Policy Forum "Oil: Never cry wolf--why the petroleum age is far from over" (21 May 2004, p. 1114), L. Maugeri has done considerable double-counting to reassure us that "the world is not running out of oil." He cites various upward revisions in historical estimates of oil reserves and resources, culminating in the 2000 U.S. Geological Survey estimate of 3021 billion barrels of ultimately recoverable resources, from which he draws the conclusion that "overall, the world retains more than 3 trillion barrels of recoverable oil resources."

Unfortunately, that 3021 figure includes the oil that has already been consumed. It consists of "undiscovered conventional oil" (732 billion barrels), "reserve growth" (688 billion barrels), "reserves remaining" (891 billion barrels), and "cumulative production" (710 billion barrels) (1). Deduct the 710 billion barrels already consumed, and the remaining oil totals 2311 billion barrels, a figure closer to other estimates.

Maugeri ignores the fact that the discovery of reserves lowers the estimate for undiscovered oil; it does not necessarily raise the total figure for ultimate recoverable oil resources.

He also calculates a "life index" of 40 years for known reserves, using current consumption figures. Using the 891 billion barrels (reserves remaining) figure would reduce that number to 32 years, but there are flaws in that calculation. Making projections based on current consumption is meaningless if consumption is rising (which it is). With a projected annual growth worldwide of 1.9% from 2001 to 2025 (2), the 32 years' supply would decline to about 26 years.

I believe we should draw very different conclusions from the present estimates. First, although the experts may quibble over their differences, they are in broad agreement: All the estimates I have seen agree within a factor of about two as to how much oil remains. The policy implications are not much different, wherever you may stand in that range. Oil resources are running down, and the supply is inelastic.

Second, we should be preparing now for a difficult transition. Europe and Japan, poor in oil resources, have gone much farther in making adjustments in energy use than the United States. Furthermore, they have stable or declining populations and similar requirements for energy and have chosen to limit demand, particularly by imposing high taxes on gasoline.

The United States is putting itself in the worst possible position for the energy transition by encouraging unchecked population growth (mostly driven by immigration) and doing very little to encourage energy efficiency.

Lindsey Grant
Santa Fe, NM, USA.
E-mail: lindseygrant@earthlink.net


Letters
Recalculating Future Oil Reserves

In his Policy Forum "Oil: Never cry wolf--why the petroleum age is far from over" (21 May 2004, p. 1114), L. Maugeri claims that new discoveries of oil and other hydrocarbons will stave off oil scarcity for many generations to come. As the physicist Albert Bartlett (1) demonstrated nearly three decades ago, "When we are dealing with exponential growth we do not need to have an accurate estimate of the size of [the] resource in order to make a reliable estimate of how long the resource will last." Assume, he said, that the entire volume of Earth is oil (6.81 1021 barrels). At the then prevailing growth rate in oil consumption of 7.04%/year, "this earth full of oil [would] last only 342 years!" Now, with China and other rapidly industrializing nations dramatically increasing their energy consumption, there seems little hope that exponential growth of hydrocarbon consumption will level off soon (2).

Of course, Earth is not made entirely of petroleum--far from it. Moreover, the alternative hydrocarbon sources that Maugeri mentions, Canadian tar sands and Venezuelan and Russian heavy oil, are no substitute for cheap oil. The petroleum geologist Walter Youngquist has noted that a considerable percentage of the energy recovered from these alternative sources is expended in their processing--two barrels out of every three in the case of tar sands and a similarly low net energy recovery for heavy oil (3). The same statement can be made about oil shale and biofuels. Ethanol from corn or sugar cane sometimes yields a net energy loss. The energy losses in producing and packaging hydrogen for the hydrogen economy will be considerable. Hydrogen is not a primary fuel, and its fundamental properties limit its ultimate utility. Nuclear power has a continuing role to play in generating electricity, but unlike oil, it is not a chemical feedstock, there are intractable safety concerns, and cheap oil and other hydrocarbons still mine and process the nuclear fuel and build the nuclear plants (4, 5).

By referring to the legitimate concerns about oil scarcity as "hysteria" and "crying wolf," Maugeri deflects us from the only course that can save industrial civilization from the consequences of its overconsumption of energy. We need to begin a crash program to develop and implement energy-saving technologies in construction, manufacturing, transportation, and agriculture while the world still has enough oil wealth left to pay for the job. And at the same time, we have to speedily change a self-destructive mindset that glorifies waste and unnecessary consumption.

David Ehrenfeld
Department of Ecology, Evolution, and Natural Resources
Cook College, Rutgers The State University of New Jersey
14 College Farm Road
New Brunswick NJ 08901-8551, USA


Special Section
WHAT DON'T WE KNOW?
What Can Replace Cheap Oil--and When?

Richard A. Kerr and Robert F. Service

The road from old to new energy sources can be bumpy, but the transitions have gone pretty smoothly in the past. After millennia of dependence on wood, society added coal and gravitydriven water to the energy mix. Industrialization took off. Oil arrived, and transportation by land and air soared, with hardly a worry about where the next log or lump of coal was coming from, or what the explosive growth in energy production might be doing to the world.

Times have changed. The price of oil has been climbing, and ice is melting around both poles as the mercury in the global thermometer rises. Whether the next big energy transition will be as smooth as past ones will depend in large part on three sets of questions: When will world oil production peak? How sensitive is Earth's climate to the carbon dioxide we are pouring into the atmosphere by burning fossil fuels? And will alternative energy sources be available at reasonable costs? The answers rest on science and technology, but how society responds will be firmly in the realm of politics.

There is little disagreement that the world will soon be running short of oil. The debate is over how soon. Global demand for oil has been rising at 1% or 2% each year, and we are now sucking almost 1000 barrels of oil from the ground every second. Pessimists--mostly former oil company geologists--expect oil production to peak very soon. They point to American geologist M. King Hubbert's successful 1956 prediction of the 1970 peak in U.S. production. Using the same method involving records of past production and discoveries, they predict a world oil peak by the end of the decade. Optimists--mostly resource economists--argue that oil production depends more on economics and politics than on how much happens to be in the ground. Technological innovation will intervene, and production will continue to rise, they say. Even so, midcentury is about as far as anyone is willing to push the peak. That's still "soon" considering that the United States, for one, will need to begin replacing oil's 40% contribution to its energy consumption by then. And as concerns about climate change intensify, the transition to nonfossil fuels could become even more urgent (see p. 100).

If oil supplies do peak soon or climate concerns prompt a major shift away from fossil fuels, plenty of alternative energy supplies are waiting in the wings. The sun bathes Earth's surface with 86,000 trillion watts, or terawatts, of energy at all times, about 6600 times the amount used by all humans on the planet each year. Wind, biomass, and nuclear power are also plentiful. And there is no shortage of opportunities for using energy more efficiently.

Of course, alternative energy sources have their issues. Nuclear fission supporters have never found a noncontroversial solution for disposing of long-lived radioactive wastes, and concerns over liability and capital costs are scaring utility companies off. Renewable energy sources are diffuse, making it difficult and expensive to corral enough power from them at cheap prices. So far, wind is leading the way with a global installed capacity of more than 40 billion watts, or gigawatts, providing electricity for about 4.5 cents per kilowatt hour.

That sounds good, but the scale of renewable energy is still very small when compared to fossil fuel use. In the United States, renewables account for just 6% of overall energy production. And, with global energy demand expected to grow from approximately 13 terawatts a year now to somewhere between 30 and 60 terawatts by the middle of this century, use of renewables will have to expand enormously to displace current sources and have a significant impact on the world's future energy needs.

What needs to happen for that to take place? Using energy more efficiently is likely to be the sine qua non of energy planning--not least to buy time for efficiency improvements in alternative energy. The cost of solar electric power modules has already dropped two orders of magnitude over the last 30 years. And most experts figure the price needs to drop 100-fold again before solar energy systems will be widely adopted. Advances in nanotechnology may help by providing novel semiconductor systems to boost the efficiency of solar energy collectors and perhaps produce chemical fuels directly from sunlight, CO2, and water.

But whether these will come in time to avoid an energy crunch depends in part on how high a priority we give energy research and development. And it will require a global political consensus on what the science is telling us.

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