The Most Energy-Efficient Countries 看全部

Next year in Copenhagen, world leaders will assemble and attempt to write the successor agreement to the 10-year-old Kyoto protocol. In order for countries to make dramatic reductions for a greener future, energy efficiency will likely be a big part of the equation.

What they'll find is a huge gap between countries with a head start, and those still in the blocks. Not surprising, the countries with the most energy-efficient economies are those who import their energy supplies.

Japan leads the way. It is, after all, birthplace of the Kyoto Protocols for climate change. More important, Japan has very little domestic energy production and is forced to import most of its fuel supply--creating a powerful economic incentive to use those expensive imports efficiently. (See "Japan's Green Gold Mine.")

In Pictures: The 10 Most Energy-Efficient Countries: ... tml?thisspeed=25000

The island nation uses 4,500 BTUs per U.S. dollar of gross domestic product, a measure known as "energy intensity," the world standard for measuring how efficient an economy is at using energy.

A country with a very high GDP and relatively little energy consumed is likely to be a very energy-efficient economy. Conversely a country with huge energy consumption and relatively little GDP is unlikely to be efficient. A BTU, or British thermal unit, is the amount of heat energy needed to raise the temperature of one pound of water by one degree Fahrenheit.

Of course, the use of energy intensity as a measure is not perfect and the results can be misleading. By the EIA's data, the country with the lowest energy intensity is Chad. True, Chad uses little energy, but the country is largely reliant on low-tech subsistence farming. Comparing it with the U.S. makes little sense.

So for our list we looked at only the 75 largest countries in terms of total GDP. Not surprisingly, the countries are wealthy and among the world's greenest as well, according to the Environmental Performance Index, a joint product of Columbia University and Yale University, which measures performance against 25 indicators, such as measures of air pollution, water supply or use of natural resources. Switzerland, which ranks third for efficiency, is ranked as the greenest country. Austria is not far behind at sixth, with Germany and the U.K. also in the top 15.

The most energy-efficient countries are all similar to Japan. In many cases, they do not have access to abundant sources of energy and have sought efficiency as a matter of energy independence--in the case of (No. 2) Denmark as an urgent national priority since the oil shocks of the 1970s. Hong Kong, Ireland, Israel and Italy all make the list as well.

The U.S. doesn't. Using energy intensity as a measure, the U.S. is using slightly more than 9,000 BTUs per dollar of GDP. The top 10 countries use 7,500 BTUs or less. China uses 35,000 BTUs per dollar of GDP. (See "China's Power Problem.")

They're far from the worst, though. At the other end of the scale are former Soviet countries: Russia, Kazakhstan, Uzbekistan and Ukraine. Ukraine uses 138,000 BTUs of energy for every dollar of GDP--roughly 30 times the level of consumption in Japan. The aging energy infrastructure of these countries, a remnant from the not-so-efficient days of Soviet planning, has much room for improvement.