More than 150 world leaders arrived at United Nations climate change talks in Paris armed with promises and accompanied by high expectations as they look to hold back the Earth’s rising temperature.

Hollande reiterated that a deal to try to keep any further increase in global temperatures to below 2 degrees Celsius needed to be “universal, differentiated and binding”, with richer countries contributing more than poorer ones.

“I can’t separate the fight with terrorism from the fight against global warming,” he said at the opening of the talks.

“These are two big global challenges we have to face up to, because we have to leave our children more than a world freed of terror, we also owe them a planet protected from catastrophes. World peace is at stake in the talks, he said. Hollande warned that there could not be a vague agreement.

“To resolve the climate crisis, goodwill, statements of intent are not enough,” Hollande said, telling world leaders that the future of humanity rested on their shoulders. “We are at breaking point.”

Besides Prime Minister Modi, other leaders including US President Barack Obama, China's Xi Jinping and Russia's Vladimir Putin are attending the opening ceremony of the 21st Conference of the Parties (COP21) tasked with reaching the first truly universal climate pact.

At the start of the summit, leaders observed a minutes' silence for Paris attack victims.

Echoing the sentiments expressed by Hollande, US President Barack Obama called the global talks on climate an “act of defiance” against terrorism that proves the world stands undeterred by ISIS-linked attacks in Europe and beyond.

Obama used his speech to salute Paris and its people for “insisting this crucial conference go on” just two weeks after attacks that killed 130 in the French capital.He said leaders had converged to show resolve to fight terrorism and uphold their values at the same time.

“What greater rejection of those who would tear down our world than marshalling our best efforts to save it,” Obama said.

The Paris climate conference will, for the first time in over 20 years of UN negotiations, aim to achieve a legally binding and universal agreement on climate, with the aim of keeping global warming below 2°C over pre-industrial temperatures.

Scientists estimate that if the world warms by more than 2°C on average above pre-industrial levels by the end of this century, the effects of climate change will become catastrophic and irreversible.

A 2°C limit has long been the goal of UN climate conferences, and current pledges from all countries are estimated to lead to warming of 2.7 °C to 3°C, although the proposed deal has a provision for increased emissions cuts in future.

Before the talks, countries like China and India have laid out plans for cuts or curbs to their emissions. These will form the centrepiece of any deal.

The most difficult issues include working out how to share the burden of taking action between rich and poor nations, how to finance the cost of adapting to global warming and the legal format of any final text.

Ahead of the summit, Prime Minister Modi had said that it is the responsibility of all to work against global warming. UN chief Ban Ki-moon underlined the need for a durable universal deal to address rising green house gas emissions.

Twenty countries, including India, the US and China, have already decided to launch an initiative to double their clean energy research and development budget over the next five years as part of global efforts to tackle climate change.