Explainer: How is extreme weather testing China's climate resilience?

Dramatic swings between extreme heat and intense rainfall are testing China's ability to cope with increasingly wild weather, as high temperatures challenge power grids and water security while floods ruin crops and threaten urban populations.

Officials have warned repeatedly that China is especially vulnerable to the impacts of climate change due to its large population and unevenly distributed water supplies, even as infrastructure is built and policies are rolled out to bolster the country's climate resilience.

HOW WORRYING IS THE HEAT?

The average number of high-temperature days stood at 4.1 in January-June, already higher than the full-year average of 2.2 days. Temperatures are expected to climb further in July and August.

In June, temperatures averaged 21.1 Celsius (70 Fahrenheit), or 0.7C higher than normal and the second-highest since 1961, with 70 monitoring stations across China smashing records. 

Northern China has borne the brunt of the extreme heat. In June, Beijing logged 13.2 days with temperatures of at least 35C, the highest number of super hot days for the month since records began in 1961, with the mercury rising to at least 40C on a few days.

Concerns are mounting over a repeat of last year's drought, the most severe in 60 years, which at its peak affected 6.09 million hectares of crops with economic losses reaching billions of yuan.

Rainfall in Yunnan province in the southwest plummeted 55% on the year in January-May. State media said in June that 3 million hectares of farmland had already suffered from drought.

ARE POWER GRIDS STRESSED?

Heatwaves spur demand for electricity to cool homes, malls and offices, taxing power supply and even triggering blackouts. In June, a first-ever emergency drill was conducted in eastern China to cope with large-scale outages.

Factories also shut when power demand exceeds supply to meet demand from residential and non-industrial users. With drought curbing hydropower output, Yunnan in February ordered a cut of 14% of its output of aluminium obtained from power-intensive electrolysis. In August last year, hydro-dependent Sichuan province mandated power cuts on most industrial users lasting 11 days.

To support base load power demand during spikes and ease the grid's reliance on hydro, China has accelerated approval of new coal mines and coal-fired power plants, which could make it harder for Beijing to achieve its carbon-reduction goals.

Last year, China approved 260 million metric tons of new mining capacity and even reopened mothballed mines. Local governments also approved at least 20.45 gigawatts of new coal power capacity in the first quarter of 2023, more than the whole of 2021.

HOW DEADLY ARE THE RAINS?

This year, the worst rains in a decade struck wheat fields in central provinces just before the harvest. That caused early germination of the grain, and 15% of the crop was unfit for human consumption. Analysts expect wheat imports this year to top 10 million tons, the highest volume ever.

Floods also threaten rice. The southern province of Hunan, which produces about 13% of China's rice, has been hit by continuous rain since late June. The agriculture ministry warned heavy rain could wash away rice pollen and devastate production.

In 2021, the central city of Zhengzhou was hit by nearly a year's worth of rain over three days, submerging neighbourhoods and flooding subway tunnels. This year, the most intense rain to date was logged by Beihai in southwestern Guangxi region, registering 614.7 millimetres (24.2 inches) over 24 hours.

China recorded its highest rainfall over a 24-hour period in 1975 in the central city of Zhumadian, with 1,060.3 mm.

WHAT IS CHINA DOING?

In 2015, China launched a "sponge city" pilot project to reduce water-logging and to prevent floods, with permeable asphalt and pavements among the potential technological solutions. But the Zhengzhou floods have raised questions about these systems when they are pushed beyond their limits.

In May, officials released plans to build a national network of canals, reservoirs and storage facilities to strengthen control over water flows and reduce the risk of floods and droughts.

However, experts say this would be expensive and environmentally disruptive, and could leave regions in the south more vulnerable to supply disruptions and later require even more infrastructure.