気候変動による食糧生産への影響

経済的影響の評価

抄録

Climate change impact on crops production may be one of the most serious problems in the next century. In order to evaluate this problem quantitatively, we developed a modeling framework to estimate an economic impact caused by climate change. The framework comprises two main models, a GIS-based potential crop productivity model and an 30-regional international trade model. Without considering thedirect impact of atmospheric CO ₂ concentration increase (CO₂ fertilization), the potential crop productivity of winter wheat will decrease 45% in India and increase 25% in Canada by the end of the next century, while that of rice and maize will not decrease so seriously in any regions. Taking these regional changes of potential productivity as technical changes in productionfunction of the international trade model, the social welfare in India will decrease considerably, 4.89%, while that in Canada and Japan will increase 0.34% and0.02% respectively. Globally, the social welfare will decrease 0.046%, which is valued at 9.5 billion loss. With considering the direct impact of CO₂ increase, the potential productivity of rice and maize will increase in most regions of the world. Although the potential productivity of winter wheat will still decrease in some regions, global social welfare will increase 0.41%, 84.4 billion gain.