China’s chief meteorologist said an extra 10 million hectares, or 247 million acres, of farmland will be required by 2030, when the population is expected to reach 1.5 billion compared with 1.3 billion today, requiring an additional 100 million tons of food.

Global warming could slash the grain harvest by five to 10 per cent, or 30-to-50 million tons by 2030, an official said, while warmer weather is expected to shorten the growing season of some grains and their seeds won’t have enough time to ripen.

In addition to problems associated with global warming, farmland has been shrinking due to uncontrolled development and rapid urbanization.