Revolution. Presently, atmospheric concentration of CO2 is responsible for more than half of greenhouse effects. The reduction of CO2 emissions has thus become one of the major environmental policy objectives of most countries. At the June 1992 Earth Summit in Rio de Janeiro, more than 150 countries signed a treaty aimed at stabilising greenhouse gases, mainly CO2. Most industrial countries have adopted a national target for stabilising CO2 emissions at 1990 levels by the year 2000. Unfortunately, CO2 emissions by OECD countries have steadily increased. The level of CO2 emissions in 2000 is estimated to be higher than that of 1990 by more than 12 per cent. The rate of increase in non-OECD countries is less than that of OECD countries, which is mainly due to the former USSR. If the former USSR is excluded, the rate of increase in non-OECD countries is much higher than that of OECD countries. In the case of APEC Asia, except for Japan, the level of CO2 emission in 1995 is higher than that of 1990 by 32 per cent.