China said yesterday it was targeting a hefty 40-45 percent cut in carbon intensity by 2020 and Beijing also announced Premier Wen Jiabao would lead the nation's charge for real climate change progress at the Copenhagen summit.

The announcements came one day after the US declared it would cut carbon emissions by 17 percent by 2020 from the 2005 level. Washington also said President Barack Obama would take part in the opening of the two-week UN climate change conference.

Experts said action by Beijing and Washington shows collective political will to reach a substantial deal in Copenhagen - something President Hu Jintao and Obama called for during their summit this month in Beijing.