地球温暖化と稲作からのメタン発生量 : その国際的動向と予測

Abstract

The purpose of this paper is to build the econometric model which can be used for predicting the future quantity of the methane CH4 emitted from the world rice growing and to investigate the preventing measures for the global warming. The carbon dioxide is the major green house effect gas in terms of the density in the air but it is said that the potential of the methane to cause the global warming is much larger than the carbon dioxide. In the case of carbon dioxide, the quantity of CO2 absorbed in the process of photosynthesys of the plants is almost offset by the quantity emitted through their burning. In this regards, the agricultural activities have more to do with the emission of the methane. In this paper, the aspects of the methane emission through the rice growing in the world are focussed on. The result of the econometric analysis on the global warming through the agricultural activities shows that the quantity of the methane CH4 emitted from the rice growing will be 0.12 billion tons in 1995 and 0.17 billion tons in 2080. This would be 20%-36% of the total quantity of the methane emitted by all sources in the earth. It is pointed out that the southeast asia emits the most methane and the second largest area is the centrally planned Asia. The increase rate of the methane quantity emitted in Africa is the largest in the world although the quantity of methane emitted is still very low at the moment.