Over 120 leaders to attend Paris climate summit — United Nations official

“To avoid any additional risk, the government has decided not to authorize climate marches in public places in Paris and in other French cities on November 29 and December 12”.

But Mr Pasztor said dozens of world leaders still planned to attend. Andrew Steer, president of the US-based World Resources Institute, said “I think, if anything, it stiffens the spine in terms of determination to really solve what is the greatest collective action problem in history”.

But he added that they are “putting their travel plans where their mouths are”, meaning that their presence in Paris should be seen as proof of how seriously they take the climate issue.

The United Nations climate change conference, widely known asCOP21 must be the turning point towards a low-emission, climate-resilient future, the top UN official dealing with climate issues said on Friday just days before the start of the global gathering in Paris, France.

The conference aims to bring about a universal agreement that will reduce greenhouse gas emissions and keep global temperatures from rising.

While it is inevitable that leaders will discuss the co-ordinated attacks in Paris claimed by the Islamic State (IS) extremist group that killed 130 people, Mr Pasztor said he expected their main focus to be on reaching an agreement, which all governments want.

The French ambassador has said that the COP21 is the biggest diplomatic event ever hosted in France and it will not only still go ahead but will be a moment of hope and solidarity. As of this morning, 171 countries which collectively account for more than 90 per cent of emissions, have now submitted national climate plans with targets.

He stressed that the Paris conference “must mark the floor, not the ceiling of our ambition”. “The right step now would be for Britain to become the first major country to enshrine net zero emissions in law, with the date determined by advice from the independent Committee on Climate Change”.