China’s overall resources of water are roughly 2,000 cubic meters, but 80 per cent of water resources are in the south. In the north, eight provinces suffer from acute water scarcity, a further four from scarcity. They account for 38 per cent of China’ agriculture, 50 per cent of its power generation, 46 per cent of its industry and 41 per cent of its population. The water resources of the 112m population of the Beijing/Tianjin/Hebei region, equate to half of acute scarcity. In the past 25 years, 28,000 rivers have disappeared. Groundwater has fallen by up to 1-3 metres a year. One consequence: parts of Beijing are subsiding by 11cm a year. The flow of the Yellow River, water supply to millions, is a tenth of what it was in the 1940s; it often fails to reach the sea. Pollution further curtails supply: in 2017, 8.8 per cent of water was unfit even for agricultural or industrial use. The political challenge is immense: China’s Five Year Plan implies halving per capita water consumption while doubling China’s 2010 GDP.

(Comment: Accepted definitions of water stress, scarcity and acute scarcity are resources of 1,700 cubic meters, 1,000 cubic meters and 500 cubic meters per person per year.)