The leaders event of the Conference of Parties (CoP) 21 climate summit started here with a minute's silence in memory of those killed in the November 13 terror attacks in this French capital.
UN Secretary General Ban Ki-moon asked for the minute's silence ahead of French President Francois Hollande's inaugural address.
The horrific attacks claimed 130 lives.
"The tragic event has forced us to focus on what is important," Hollande said in his speech.
"We face two major global challenges - terrorism and climate change - and we must overcome both," he added.
