Japan's rice output will fall significantly and most of the nation's beech forests could die off if temperatures rise due to increased carbon dioxide in the atmosphere, according to a report on global warming compiled by the Agriculture, Forestry and Fisheries Ministry.

The ministry will work on such countermeasures as developing new rice breeds resistant to heat or lack of water, to be discussed at a meeting April 25 of its global warming task force, the officials said. The measures are to be announced in July.

According to the ministry forecast, if carbon dioxide levels in the atmosphere double in density, some prefectures, mostly in central and western Japan, will lose as much as 40 percent of their rice yields. However, some areas in northern Japan will see their rice yields grow.