Escalating climate risks revealed by Blue Book

China’s average summer temperature and coastal sea levels have reached new highs, according to this year’s edition of the China Climate Change Blue Book.

In 1901–2022, the country warmed more quickly than the global average. Extreme heat events, which usually means three consecutive days topping 35C, are happening more regularly. Last year saw the highest frequency of such events since records began in 1961, the book shows.

Average annual precipitation has been on the rise as well, with an increase in the number and frequency of extreme precipitation events. Regional variations in precipitation change are emerging. Notably, the Qinghai-Tibet region has experienced a significant increase in average annual precipitation, while the south-west region has seen an overall decline.

Sea-level rise has been accelerating. In 1980–2022, it rose 3.5mm per year on average, but from 1992–2022 that figure grew to 4mm – higher than the global average for the same period. 

Glacier melt has also been accelerating, the Blue Book says. Meanwhile, degradation of permafrost along the Qinghai-Tibet Highway is becoming increasingly apparent.

One positive trend noted by the book is that China’s mangrove forests, which absorb carbon and therefore slow climate warming, have been recovering. The country’s mangrove area shrunk from the 1970s to the early 2000s, but has steadily recovered in the past two decades. The total area of mangrove had reached 240 square kilometres by 2022, bringing it back to its 1980 level. In Guangdong, Hong Kong, and Macao, the total area has basically returned to its 1990 levels.

China has been publishing the Blue Book since 2018 to assist policy-making processes. This year it was released while heatwaves rattled the north of the country. 

Recent research published in Nature Communications shows that Beijing, Hebei and Tianjin are among the world’s regions most at risk of experiencing high-impact heatwaves.

Read China Dialogue’s earlier article on how to improve China’s extreme weather response.