A long spell of extreme hot and dry weather is affecting energy, water supplies and food production across China
ENVIRONMENT 23 August 2022
Low rainfall and record-breaking heat across much of China are having widespread impacts on people, industry and farming. River and reservoir levels have fallen, factories have shut because of electricity shortages and huge areas of crops have been damaged. The situation could have worldwide repercussions, causing further disruption to supply chains and exacerbating the global food crisis.
People in large parts of China have been experiencing two months of extreme heat. Hundreds of places have reported temperatures of more than 40°C (104°F), and many records have been broken. Subway stations have set up rest areas where people can recover from the heat.
On 18 August, the temperature in Chongqing in Sichuan province reached 45°C (113°F), the highest ever recorded in China outside the desert-dominated region of Xinjiang. On 20 August, the temperature in the city didn’t fall below 34.9°C (94.8°F), the highest minimum temperature ever recorded in China in August. The maximum temperature was 43.7°C (110.7°F).
It is the longest and hottest heatwave in China since national records began in 1961. According to weather historian Maximiliano Herrera, who monitors extreme temperatures around the world, it is the most severe heatwave recorded anywhere.
“This combines the most extreme intensity with the most extreme length with an incredibly huge area all at the same time,” he says. “There is nothing in world climatic history which is even minimally comparable to what is happening in China.”
Together with the extreme heat, low rainfall in parts of China has led to rivers falling to low levels, with 66 drying up completely. In parts of the Yangtze, water levels are the lowest since records began in 1865. In a few places, local water supplies have run out and drinking water has had to be trucked in.
On 19 August, China announced a national drought alert for the first time in nine years.
Hydroelectricity generation has fallen because of the low water levels. Sichuan has been especially affected because it normally gets 80 per cent of its electricity from hydropower. Thousands of factories in the province have had to cease operations because of electricity shortages amid high demand for air conditioning. Offices and shopping malls were also told to reduce lighting and air conditioning to save power.
In Sichuan alone, 47,000 hectares of crops are reported to have been lost and another 433,000 hectares damaged. The agriculture ministry has said it will try to increase rainfall by seeding clouds. It remains scientifically unclear whether cloud seeding makes a significant difference.
Lower crop yields in these regions could worsen the global food crisis. Global food prices hit record levels even before Russia invaded Ukraine, and though they have fallen since March, they remain higher than in previous years. However, China has built up large grain reserves in recent years, so it can make up for some shortfall.
According to a 2021 report from the Intergovernmental Panel on Climate Change, droughts have been increasing as a result of global warming and will become more frequent and severe as the planet continues to warm.
The hidden science of weather and climate change Simon Clark at New Scientist Live this October
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