Paris: Nearly 150 world leaders including Prime Minister Narendra Modi gathered Monday in Paris to attend the official start of the much-anticipated climate summit aimed at reaching a historic deal to reduce greenhouse gas emissions that cause global warming.
The summit is being held under the shadow of the deadly Paris terror attacks that killed 130 people two weeks ago.
About 2,800 police and soldiers will secure the conference site and more than 6,000 have been deployed in the city.
Besides Modi, other leaders including US President Barack Obama, China's Xi Jinping and Russia's Vladimir Putin will attend the opening ceremony of the 21st Conference of the Parties (COP21) tasked with reaching the first truly universal climate pact.
The 12-day 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.
With more than 180 countries having already submitted their plans to reduce the harmful emissions that cause climate change, Obama expressed optimism over the success of the Paris Summit.
"I am optimistic about what we can achieve - because I've already seen America take incredible strides these past seven years," Obama said before leaving for Paris.
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.