Turn down that thermostat, permanently

2. The insufficiency of primary energy supplies: The capacity of the global energy industry to satisfy demand is shrinking. By all accounts, the global supply of oil will expand for perhaps one half-decade before reaching a peak and beginning to decline, while supplies of natural gas, coal and uranium will probably grow for an additional decade or two before peaking and commencing their own inevitable declines. In the meantime, global supplies of these existing fuels will prove incapable of reaching the elevated levels demanded.

Take oil. The U.S. Department of Energy claims that world oil demand, expected to reach 117.6 million barrels per day in 2030, will be matched by a supply that -- miracle of miracles -- will hit exactly 117.7 million barrels (including petroleum liquids derived from allied substances like natural gas and Canadian tar sands) at the same time. Most energy professionals, however, consider this estimate highly unrealistic. "One hundred million barrels is now in my view an optimistic case," the CEO of Total, Christophe de Margerie, typically told a London oil conference in October 2007. "It is not my view; it is the industry view, or the view of those who like to speak clearly, honestly, and [are] not just trying to please people."

Similarly, the authors of the Medium-Term Oil Market Report, published in July 2007 by the International Energy Agency, an affiliate of the OECD, concluded that world oil output might hit 96 million barrels per day by 2012, but was unlikely to go much beyond that as a dearth of new discoveries made future growth impossible.

Daily business-page headlines point to a vortex of clashing trends: Worldwide demand will continue to grow as hundreds of millions of newly affluent Chinese and Indian consumers line up to purchase their first automobile (some selling for as little as $2,500); key older "elephant" oil fields like Ghawar in Saudi Arabia and Canterell in Mexico are already in decline or expected to be so soon; and the rate of new oil-field discoveries plunges year after year. So expect global energy shortages and high prices to be a constant source of hardship.

3. The painfully slow development of energy alternatives: It has long been evident to policymakers that new sources of energy are desperately needed to compensate for the eventual disappearance of existing fuels as well as to slow the buildup of climate-changing "greenhouse gases" in the atmosphere. In fact, wind and solar power have gained significant footholds in some parts of the world. A number of other innovative energy solutions have already been developed and even tested out in university and corporate laboratories. But these alternatives, which now contribute only a tiny percentage of the world's net fuel supply, are simply not being developed fast enough to avert the multifaceted energy catastrophe that lies ahead.

According to the U.S. Department of Energy, renewable fuels, including wind, solar and hydropower (along with "traditional" fuels like firewood and dung), supplied but 7.4 percent of global energy in 2004; biofuels added an additional 0.3 percent. Meanwhile, fossil fuels -- oil, coal and natural gas -- supplied 86 percent of world energy, nuclear power an additional 6 percent. Based on current rates of development and investment, the DOE offers the following dismal projection: In 2030, fossil fuels will still account for exactly the same share of world energy as in 2004. The expected increase in renewables and biofuels is so slight -- a mere 8.1 percent -- as to be virtually meaningless.

In global warming terms, the implications are nothing short of catastrophic: Rising reliance on coal (especially in China, India and the United States) means that global emissions of carbon dioxide are projected to rise by 59 percent over the next quarter-century, from 26.9 billion metric tons to 42.9 billion tons. The meaning of this is simple. If these figures hold, there is no hope of averting the worst effects of climate change.

When it comes to global energy supplies, the implications are nearly as dire. To meet soaring energy demand, we would need a massive influx of alternative fuels, which would mean equally massive investment -- in the trillions of dollars -- to ensure that the newest possibilities move rapidly from laboratory to full-scale commercial production; but that, sad to say, is not in the cards. Instead, the major energy firms (backed by lavish U.S. government subsidies and tax breaks) are putting their mega-windfall profits from rising energy prices into vastly expensive (and environmentally questionable) schemes to extract oil and gas from Alaska and the Arctic, or to drill in the deep and difficult waters of the Gulf of Mexico and the Atlantic Ocean. The result? A few more barrels of oil or cubic feet of natural gas at exorbitant prices (with accompanying ecological damage), while nonpetroleum alternatives limp along pitifully.

Next page: What this adds up to is simple and sobering: The end of the world as you've known it