More than 1,150 sq km of low-lying land in the Pearl River Delta, including parts of Guangzhou, Foshan and Zhuhai , will be under water by 2050 if global warming continues at its present pace, meteorological officials have warned.
If the pace picks up, the scenario could play out 20 years earlier.
The report does not mention any impact on Hong Kong, but it includes a map showing areas which could be lost to rising sea levels by 2030 - among them parts of Lamma and Po Toi Island, and land in Clear Water Bay, Kwai Chung and Sai Kung.
Temperatures in Guangdong had increased 'critically' since the late 1990s, the Guangdong Meteorological Bureau said on Tuesday in its first report on climate change.
The Pearl River Delta had become a key warming zone because of its high population density and rapid urbanisation and industrialisation, according to the report, the result of three years' research by more than 20 senior meteorologists.
'The average temperature increase in north Guangdong was lower than 0.15 degrees Celsius per 10 years, but in the Pearl River Delta reached 0.3 degrees,' it said. 'Some specific cities and counties in the region were even up to 0.4 degrees.'