With more than 120 heads of state and government present, the Climate Change summit opened here Tuesday.
Addressing the summit, UN Secretary General Ban Ki-moon asked public and private sector leaders to commit to taking action on climate change.
He urged them to lay the groundwork for a global climate action agreement.
Ban told the gathering that there is no time to waste. If the world community does not act now it will have to pay much more than what it is already paying.
Action should be taken to halt the advance of global climate change, Ban said noting there is no "Plan B" for action as there is no "Planet B".