At the end of last month, US President Barack Obama announced he would be attending the Copenhagen meeting and would be going armed with a reduction target of 17% below 2005 levels by 2020 (see page 6). The news was immediately followed by China’s announcement that it would commit to a voluntary 40–45% cut in carbon intensity by 2020.

Experts say the dual pledge has boosted sentiment for progress at the conference, but without legislative backing, Obama will be powerless to sign up to anything