A deal has been reached by more than 150 countries to limit the use of harmful greenhouse gases in what the UN called the largest breakthrough since the Paris climate change agreement.

Delegates met in Rwanda for talks on hydrofluorocarbons, or HFCs – gases used in air conditioners and refrigerators that are far more potent than carbon dioxide.

The new agreement is “equal to stopping the entire world’s fossil fuel CO2 emissions for more than two years”, said David Doniger, a director at the Natural Resources Defence Council, an environmental advocacy group based in the United States.

The deal to cap and reduce the use of HFCs – described as the world’s fastest-growing climate pollutant – was announced on Saturday morning following a night of negotiations.

A gradual process beginning in 2019 has been agreed with action by developed countries including the United States, the world’s second worst carbon dioxide emitter after China.

John Kerry, US Secretary of State, who took part in meetings in the capital city Kigali, said the deal was a “monumental step forward.”

Air conditioning units on an apartment block in Hong Kong (Getty Images / iStockphoto)

More than 100 developing countries, including China, will start taking action by 2024.

A small group of countries including India, Pakistan and some Gulf states, pushed for and secured an even later start in 2028, saying their economies need more time to grow.

Environmental groups had hoped that the deal could reduce global warming by half a degree Celsius before the end of this century.

This agreement gets about 90 per cent of the way there, said Durwood Zaelke, president of the Institute for Governance and Sustainable Development.

Mr Zaelke’s US based campaign group said this is the “largest temperature reduction ever achieved by a single agreement”.

“History is made. Montreal Protocol countries agree to curb powerful greenhouse gases in largest climate breakthrough since Paris,” tweeted the UN Environment Programme.

Unlike the 2015 Paris agreement, the Kigali deal, agreed by 197 countries, is legally binding, has very specific timetables and has an agreement by rich countries to help poor countries adapt their technology.

HFCs are less abundant than carbon dioxide, but Mr Kerry said last month that they currently emit as much pollution as 300 coal-fired power plants each year.

That amount will rise significantly over the coming decades as sales of air conditioner and refrigerator sales soar in emerging economies like China and India.

The deal amends the Montreal Protocol on Substances that Deplete the Ozone Layer, an international treaty agreed in 1987.

“Compromises had to be made, but 85 per cent of developing countries have committed to the early schedule starting 2024, which is a very significant achievement,” said Clare Perry, UK climate campaign leader with the Environmental Investigation Agency.

HFCs, also found in inhalers and insulating foams, were introduced in the 1980s as a substitute for ozone-depleting gases.

They do not harm the ozone layer like chlorofluorocarbons and similar gases which were eliminated under the Montreal Protocol.

Mike Childs, head of policy at Friends of the Earth, said while he welcomed the deal, it was important to recognise that HFCs are a small problem compared to carbon dioxide emissions.

“This is a very welcome step forward, and another important sign that the international community is at last getting serious on climate change,” he said.

Paris climate talks in pictures Show all 12 1 /12 Paris climate talks in pictures Paris climate talks in pictures A man is covered with a multi-coloured banner with the message, "Climate" as environmentalists attend a demonstration near the Eiffel Tower in Paris, France, during the World Climate Change Conference 2015 (COP21) that meets in Le Bourget, December 12, 2015 Reuters Paris climate talks in pictures French President Francois Hollande (C) and French Foreign Minister Laurent Fabius (R) applaud after a statement at the COP21 Climate Conference in Le Bourget, north of Paris, on December 12, 2015. The years-long quest for a universal pact to avert catastrophic climate change neared the finish line today with conference host France announcing that the final draft had been completed in the early hours of the morning. Getty Paris climate talks in pictures US Secretary of State John Kerry (C) speaks with China's Special Representative on Climate Change Xie Zhenhua (R) and officials at the COP21 Climate Conference in Le Bourget, north of Paris, on December 12, 2015. The years-long quest for a universal pact to avert catastrophic climate change neared the finish line today with conference host France announcing that the final draft had been completed in the early hours of the morning. Getty Paris climate talks in pictures Delegates and members of NGO's read and work on copies of 'The adoption of the Paris agreement' is pictured after the announcement of the final draft by French Foreign Affairs minister Laurent Fabius at the COP21 Climate Conference in Le Bourget, north of Paris, on December 12, 2015. The years-long quest for a universal pact to avert catastrophic climate change neared the finish line with conference host France announcing that the final draft had been completed in the early hours of the morning Getty Paris climate talks in pictures UN climate chief Christiana Figueres (C) speaks with French President Francois Hollande (L), United Nations Secretary General Ban Ki-moon (2ndL) and French Foreign Minister Laurent Fabius (R) after a statement at the COP21 Climate Conference in Le Bourget, north of Paris, on December 12, 2015. The years-long quest for a universal pact to avert catastrophic climate change neared the finish line today with conference host France announcing that the final draft had been completed in the early hours of the morning Getty Paris climate talks in pictures A Swiss Dominican priest poses with activists dressed as polar bears as activists gather for a demonstration to form a giant red line at the Avenue de la Grande armee boulevard in Paris on December 12, 2015, as a proposed 195-nation accord to curb emissions of the heat-trapping gases that threaten to wreak havoc on Earth's climate system is to be presented at the United Nations conference on climate change COP21 in Le Bourget, on the outskirts of Paris. Getty Paris climate talks in pictures Activists hold up a giant banner reading 'Climate justice' by association 'ourpowercampaign' during a demonstration near the Arc de Triomphe at the Avenue de la Grande armee boulevard in Paris on December 12, 2015, as a proposed 195-nation accord to curb emissions of the heat-trapping gases that threaten to wreak havoc on Earth's climate system is to be presented at the United Nations conference on climate change COP21 in Le Bourget, on the outskirts of Paris. Getty Paris climate talks in pictures Representatives of indigenous peoples demonstrate in Paris, France, as the World Climate Change Conference 2015 (COP21) continues at Le Bourget, December 12, 2015. Reuters Paris climate talks in pictures Environmentalists demonstrate near the Arc de Triomphe in Paris, France, as the World Climate Change Conference 2015 (COP21) continues at Le Bourget, December 12, 2015. Reuters Paris climate talks in pictures Environmentalists demonstrate near the Arc de Triomphe in Paris, France, as the World Climate Change Conference 2015 (COP21) continues at Le Bourget, December 12, 2015. Reuters Paris climate talks in pictures Activists form a giant red line during a demonstration on the Avenue de la Grande armee boulevard in Paris on December 12, 2015, as a proposed 195-nation accord to curb emissions of the heat-trapping gases that threaten to wreak havoc on Earth's climate system is to be presented at the United Nations conference on climate change COP21 in Le Bourget, on the outskirts of Paris ALAIN JOCARD/AFP/Getty Images Paris climate talks in pictures The slogan "No Plan B" is projected on the Eiffel Tower as part of the World Climate Change Conference 2015 (COP21) in Paris, France, December 11, 2015. Reuters

“However HFCs are only a small part of the climate change problem. Carbon dioxide, particularly from burning fossil fuels, is a much bigger threat.”

Mr Childs said governments including the UK should invest in renewable energy and limit damage to the environment caused by airport expansion and fracking.

“Ministers mustn’t undermine the agreement to phase out HFCs by pushing new sources of climate-wrecking carbon pollution,” he said.

Environment Secretary Andrea Leadsom said: "The UK has already pledged to phase down use of HFCs by 80 per cent by 2030 and today's historic agreement means the rest of the world will be following our lead, after UK negotiators worked through the night at UN talks in Rwanda to achieve the deal.