parigi-570x350A historic, legally binding climate deal that aims to hold global temperatures to a maximum rise of 1.5C above pre-industrial levels, staving off the worst effects of catastrophic global warming, has been secured.

After 20 years of ‘fraught’ and sometimes utterly unproductive UN climate talks, Paris has seen all countries agree to reduce emissions, promise to raise $100bn a year by 2020 to help poor countries adapt their economies, and accept a new goal of zero net emissions by later this century.

Formally adopted in Paris by 195 countries, the first universal climate deal will see an accelerated phase-out of fossil fuels, the growth of renewable energy

As the final text of the agreement was released, the French president, François Hollande, said: “This is a major leap for mankind. The agreement will not be perfect for everyone, if everyone reads it with only their own interests in mind. We will not be judged on a clause in a sentence, but on the text as a whole. We will not be judged on a word, but on an act.”

Economist Lord Stern added: “This is a historic moment, not just for us but for our children, our grandchildren and future generations. The Paris agreement is a turning point in the world’s fight against unmanaged climate change which threatens prosperity. It creates enormous opportunities as countries begin to accelerate along the path towards low-carbon economic growth.”

The British prime minister, David Cameron, also welcomed the deal, praising those involved for showing what ambition and perseverance could do. “We’ve secured our planet for many, many generations to come – and there is nothing more important than that,” he said.

Climate scientists and activists cautioned that while the agreement was unexpectedly ambitious, the measures did not go far enough. “The cuts promised by countries are still insufficient, but the agreement sends a strong message to business, investors and cities that fossil fuels belong to the past,” said Corinne Le Quere, director of the UK’s Tyndall Centre for Climate Change Research.

However, US  President Barak Obama said the deal was “the best chance we have to save the one planet we have”. He said it could be a “turning point” towards a low-carbon future.

China, the world’s biggest polluter, also hailed the deal, as did India. But some campaigners said it did not go far enough to protect the planet.

The Paris pact aims to curb global warming to less than 2C (3.6F) by the end of the century.

Nearly 200 countries took part in tense negotiations in the French capital over two weeks, striking the first deal to commit all nations to cut emissions.

The agreement – which is partly legally binding and partly voluntary – will come into being in 2020