Leaders of 125 countries meet this Tuesday at the United Nations headquarters in New York, United States, at the summit on climate change.
The objective of the meeting is to obtain the support of the member states so that next year they sign a global agreement on climate change at a meeting that will take place in Paris.
«Climate change is the defining issue of our time. Now is the time to act,» UN Secretary-General Ban Ki-moon said before the summit began.
With so many nations participating in the one-day meeting, there will be three separate sessions taking place simultaneously.
The BBC’s Nick Bryant says the real negotiations are expected to take place at a private dinner on Tuesday night, at which Ban will receive a select list from around 20 countries.
But Bryant cautions that the absence of leaders from China, Russia and India (whose Prime Minister Narendra Modi will arrive later this week) does not bode well.
Nor are Australia and Canada participating.
Ban called for leaders attending the summit to come with pledges of action.
He wants to hear commitments to cut carbon emissions and offers to help those most affected.