Tens of millions of farmers in north and north-east China could face dramatic losses of income as a result of climate change, which is liable to exacerbate already serious droughts in those regions, according to a new study by consultants McKinsey.

As many as 35m farmers could lose more than 50 per cent of their incomes if measures are not taken to prepare for the impact of higher temperatures in the two regions, according to the study.

The north and north-east of China contain some of the main grain-growing regions of the country, making them part of the backbone of the country's huge agricultural sector, however they have already experienced some of the worst droughts in half a century this year. The latest in a series of stark warnings about the potential impact of climate change on China, the study underlines why Beijing has started to take more decisive steps over the past year to restrain the growth in Chinese carbon emissions.