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Monday, Nov. 19, 2007

Feasible cuts in emissions

Debate is raging over the pros and cons of the proposed target of halving global greenhouse-gas emissions by 2050. The goal, initially proposed last June by then Prime Minister Shinzo Abe, was supported by German Chancellor Angela Merkel and other leaders at the Group of Eight summit at Heiligendamm, Germany. The leaders agreed to conduct more discussions on the subject at the G8 summit at Lake Toya, Hokkaido, in 2008.

A noted energy-issue expert says that to achieve the goal, developed nations ("Annex I" countries, or Western industrial nations, and the former Soviet and East European countries) must decrease their emissions toward zero, assuming that developing countries' total emissions will change little in coming years. This is because developed and developing nations each account for about 50 percent of global emissions. I disagree with this view.

Developing nations have abundant opportunities for low-cost reduction of greenhouse gas emissions. Although they have coal-burning power stations and steelworks with obsolete equipment, Japan could help reduce their CO2emissions by 20 percent by transferring its existing conventional technologies.

Meanwhile, the United States and other industrial countries, which benefit from low energy costs and have little enthusiasm for saving energy resources, have ample room for cutting back on CO2emissions. The U.S., too, could reduce CO2emissions by about 20 percent by replacing old equipment at its coal-burning power stations and steelworks with energy-efficient Japanese equipment.

By improving the fuel efficiency of automobiles, it should be possible for the U.S. to cut CO2 emissions from vehicles by 20 percent.

So, it should be possible to cut CO2emissions by 20 percent by spreading existing state-of-the-art energy-saving technologies worldwide on the basis of the Japanese "top runner method" — in which energy-saving standards for automobiles and electronic appliances are set above those of the most energy-efficient products.

Next, how much can CO2emissions be reduced through lifestyle changes? Ideas include witching from fuel-guzzling large cars to efficient compacts, using public transport as much as possible, replacing incandescent lamps with fluorescent lamps, obliging convenience stores to close at 11 p.m., removing unnecessary automatic doors and soft-drink vending machines, and raising the load ratios of trucks to improve the efficiency of distribution systems.

Among ideas for new homes are using more insulating materials and installing double-pane windows, mounting solar panels and solar water heaters on the roof, improving ventilation, and making better use of sunshine.

Other ideas include introducing daylight saving time, encouraging an "early to rise, early to bed" lifestyle, and promoting the fashion of dressing coolly in summer and warmly in winter to save power consumption.

Through these and other measures, Japan could reduce CO2 emissions of its home and business sectors — which account for 35 percent of total emissions — by 20 percent. This would amount to a 7 percent cut in total emissions.

Thinking of 2050, it should be remembered that there are limits to the span of time in which crude oil will be available for exploitation. Currently this span — known total deposits divided by annual production — is estimated at 41 years.

Economic growth in developing countries inevitably will cause the denominator to increase, accelerating the price increases for crude. As a result, exploitation of undersea oil fields, which require giant investments for prospecting and development, is likely to expand, causing the numerator to increase. But since the denominator is likely to grow faster than the numerator, crude prices are likely to continue skyrocketing.

If gasoline prices rise to the level of ¥500 per liter following spikes in the price of crude, gasoline-powered automobiles will become extreme luxuries due to high operating costs. Bioethanol, an alternative fuel, must be considered a limited resource since it could lead to higher food prices as well as the destruction of the environment.

The only viable alternatives are electric cars or fuel-cell cars powered by electricity generated as a byproduct of combining hydrogen with oxygen in the air to produce water. Hydrogen is produced by the electrolysis of water.

At present, electric cars can go no more than 200 kilometers on a six-hour charge. Yet, the development of fast-recharging batteries reportedly is being expedited. If technological progress makes it possible for a driver to recharge a battery for another 200 kilometers of driving, say, while having a cup of coffee at a recharge station, electric cars will be become more practical.

Liquid fuel is essential for aircraft and ships. Rare biofuels, therefore, should be reserved for this purpose.

One issue that should be considered is the makeup of electricity supplies. There are three conceivable options — increasing dependence on nuclear power, maximizing the use of solar, wind and hydroelectric power, and applying the revolutionary technology of carbon capture and storage (CCS) to CO2 thus making zero-emission coal-burning power generation possible. The idea is to develop electric automobiles while avoiding additional CO2 emissions. All of these options, however, are troubled by feasibility.

A fourth option would be to avoid riding automobiles. Rich people, of course, would freely travel in gasoline-powered automobiles while high gasoline prices would put automobiles out of reach for most people.

Whichever option it chooses, Japan could cut automobile CO2 emissions, which account for 20 percent of all emissions, to almost zero. If industrial countries and major CO2 emitters are obliged to cut their emissions while crude prices continue to rise, CO2 emissions of the world's transport sector will inevitably decrease sharply.

In 1972, the Club of Rome, a think tank, published a book entitled "Limits to Growth," warning that depletion of resources could slow economic growth. Depletion of resources, however, would help prevent global warming. Use of renewable energies and development of innovative technologies are likely to remove the limits to growth and make it possible to achieve the goal of drastically reducing CO2 emissions.

Takamitsu Sawa is a professor at Ritsumeikan University's Graduate School of Policy Science and a specially appointed professor at Kyoto University's Institute of Economic Research.

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