Scientists warn that climate change could cut China's food production 10 percent by 2050.

The official report released at the 10th annual UN climate change conference, said given current conditions, the damage would hit China between 2030 and 2050.

The report is based on an inventory of greenhouse gas emissions carried out between 1990 and 1994.

Some 5,000 scientists, environmental activists and government officials from nearly 190 countries attended the two-week conference that started last Monday.

A focus of this year's conference is preparation for the implementation of the 1997 Kyoto Accord, the world's most ambitious and complex environmental treaty.

The accord legally commits 39 industrial nations and territories to trim their output of six greenhouse gases -- especially carbon dioxide -- by at least 5.2 percent by 2012, compared with 1990 levels.

Russia's ratification in November gave the protocol the final stamp of approval needed to go into force on February 16. China signed the accord and ratified it in 2002.