The study predicts 30% to 40% decline in agriculture capacity in India over the time. It also says about the possibility of farmlands turning into desert in many parts of the southern hemisphere in the present century.
However a handful of rich countries like US, Canada, Russia and some European countries are likely to benefit on account of global warming.
According to the lead author of the study, William Cline the projected beneficial results to crops on account of carbon dioxide concentration in the atmosphere does not hold good and would flatten out over time.
Cline said that crops like maize would not benefit from carbon dioxide concentration. Some crops can gain from increased carbon dioxide concentration in the atmosphere, but that only to the extent of 15%. Wheat, rice and soybeans are continuing to benefit from increased carbon dioxide emissions, but that that improvement is likely to taper off, he said.
Cines caution is significant in the context as India has already witnessed damage to wheat crop in the recent past, due to sudden spurts in temperatures before ripening. Perennial rivers are gradually drying up and aberration in rainfall are being noticed at regional levels. A shift in monsoon rainfall pattern has occurred since last three years with heavy rainfall in drought prone areas and scanty rain in flood prone areas
The study also said that global farm productivity would decline by in the range of 3% to 16% by 2080. In Australia crop yield would decline in the range of 16% to 27%. Among the developing countries, Sudan and Senegal are expected to witness over 50% decline, resulting in a collapse of farm system.