Published: January 18, 2009

From plug-in cars to carbon capture to wind farms linked to “intelligent” power grids, many of the solutions pitched to restructure the country’s energy system and confront global warming rely on a faith in high tech: we expect, or at least hope, that an Apollo project, the energy equivalent of the dot.com revolution or some other burst of creative genius will engineer the problem away.

Obviously, game-changing technologies will play a big role in cutting America’s consumption of fossil fuels. They will also be essential to achieving the reductions in greenhouse gas emissions that most scientists think will be necessary to avoid the worst consequences of climate change. But as it frames its strategy to deal with both problems, the Obama administration cannot overlook the low-hanging fruit — the gains to be had from making existing technologies more efficient.

The plain truth is that the United States is an inefficient user of energy. For each dollar of economic product, the United States spews more carbon dioxide into the atmosphere than 93 of 137 countries tracked in the indicators of the International Energy Agency. Those doing better include not only cutting-edge nations like Japan but low-tech countries like Thailand and Mexico.

True, energy efficiency has improved, especially in states like California. But American drivers, households and businesses still use more energy than those in most other rich countries to do the same thing. The United States spends more energy to produce a ton of cement clinker than Canada, Mexico and even China. It is one of the most energy-intensive makers of pulp and paper, emitting more than three times as much carbon dioxide per ton as Brazil and twice as much as South Korea.

Per-capita carbon dioxide emissions by households in the United States and Canada are the highest in the world — in part because of bigger homes. And the energy efficiency of electricity production from fossil fuels is lower in the United States than in most rich countries and some poor ones, mainly because of the higher share of coal in the mix.

Transportation tells the same story. The United States uses the most energy per passenger mile among the 18 rich economies surveyed by the energy agency. In 2006, the American auto fleet used, on average, a little less than five gallons of gas to travel 100 miles. The Irish went the same distance with under four gallons, the Italians with less than three, basically because they use smaller cars that get better mileage.

The Union of Concerned Scientists points out that switching from an S.U.V. that gets 14 miles per gallon to one that gets 16 would save the same amount of fuel as swapping a 35-mile-a-gallon car for a 51-m.p.g. new generation gas-sipper. This is not an argument for more S.U.V.’s. It simply shows that we can wring savings from modest efficiency gains in products we already use.

A study by McKinsey & Company last year argued that most of the carbon abatement needed between now and 2030 could be achieved with existing technologies, things like insulating homes, improving fuel efficiency, and switching to concentrated laundry detergents to reduce packaging and transport costs. Merely improving transmissions would vastly increase fuel economy.

A quantum jump in energy efficiency will still require political leadership. Cheap energy has kept America from making the necessary investments. Yet they must be made; neither the country nor the atmosphere can wait for high tech to ride to the rescue.

This article has been revised to reflect the following correction:

Correction: January 24, 2009
An editorial on Monday placed the United States incorrectly on a list of carbon dioxide emitters. The country is ranked 93 out of 137, not 75 out of 107.
 

A version of this article appeared in print on January 19, 2009, on page A24 of the New York edition.

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