President Obama has joined the Copenhagen climate summit talks, but with no new proposals to break the deadlock many have blamed in large part on his administration. Just over an hour ago, President Obama addressed the plenary with a call on world leaders to act “boldly and decisively.” But he offered no change to the US offer to reduce emissions by just four percent of 1990 levels, despite authoritative scientific calls for a 25 to 40 percent reduction. Obama also reiterated the US pledge of $10 billion for an annual climate fund which poorer nations have dismissed as insufficient.