China's sea level hit a record high in 2012 due to global warming and land subsidence, threatening millions of coastal residents, according to a government report.

The State Oceanic Administration report released on Tuesday said that last year, the sea level rose 122 millimeters more than the average level from 1975 to 1993, about 53 mm higher than 2011.

"The rising temperatures from increasing greenhouse gas emissions and the land subsidence nationwide led to the high seas," said Liu Kexiu of the National Marine Data and Information Service.