Representatives from 168 countries are at the United Nations Headquarters in New York today to sign the COP21 Paris Agreement.

Some 60 heads of state and government, including French President Francois Hollande, Chinese vice-premier Zhang Gaoli, Canadian Prime Minister Justin Trudeau and US Secretary of State John Kerry will be among the signatories.

The UK’s representativeParis Climate Agreement will be Energy Minister Lord Bourne and ahead of the signing, Britain’s Energy Secretary Amber Rudd said: “The global deal reached in Paris was a significant milestone in tackling climate change, helping to safeguard our long-term economic security and giving clear direction to businesses as we transition to a low carbon economy.”

With the UK government pledging to shut all coal plants by 2025, Rudd added that Britain “is one of the first developed countries to deliver on a commitment to taking coal off the system, putting an end date on it as part of the action we are taking to cut emissions as cost effectively as possible.”

Catherine Mitchell, Professor or Energy Policy at Exeter University, said: “Climate change is the fight of our time. World temperatures are on an upward trajectory year on year, and we need to find a way to decarbonise our economies and lifestyles, if we are to live in a future world that we recognise. Switching to renewable energy and green gas is one of the simplest and easiest ways to achieve this.”

The Paris signing has been timed to coincide with Earth Day, an annual event now in its 46th year that aims to focus attention on environmental issues.