Climate change talks – the 21st session of the Conference of the Parties (COP21) – have begun in Paris, aimed at signing a long-term deal to reduce global carbon emissions.
More than 150 world leaders have converged to launch the two-week talks.
The last major meeting in 2009 ended in failure. However, French Foreign Minister Laurent Fabius, who is chairing the meeting, said a deal was within reach.
Most of the discussions are expected to centre on an agreement to limit global warming to 2C (35.6F).
Peruvian Environment Minister Manuel Pulgar Vidal declared this year’s meeting open on November 30.
Strong action on carbon emissions is essential for multiple reasons, said Manuel Pulgar Vidal, who hosted last year’s UN climate conference in Lima.
Manuel Pulgar Vidal said a deal would show the world that countries can work together to fight global warming as well as terrorism.
Christiana Figueres, the head of the UN’s climate change negotiations, addressed delegates at the start of the summit.
The talks are taking place amid tight security, two weeks after Paris terror attacks claimed by ISIS.
Negotiators from 195 countries will try to reach a deal at the meeting.
This year, world leaders are attending the start of the two-week meeting to give impetus to the talks.
Some 150 heads of state, including President Barack Obama and his Chinese counterpart Xi Jinping, have arrived at the summit.