Prime Minister Justin Trudeau is at a sprawling airfield outside Paris where world leaders have gathered for the start of two weeks of international climate negotiations.

Leaders and heads of government from some 150 countries were on hand as French President Francois Hollande formally kicked off the 21st United Nations “Council of the Parties” – or COP-21.

Each leader is to make a short address today in two simultaneous work sessions in an unusual start for a UN climate conference, where leaders typically arrive in the closing days to announce the outcome.

Trudeau has scheduled an exhausting round of bilateral meetings on the sidelines of the conference today before flying back to Ottawa late this evening.