Governments have signalled an end to the fossil fuel era, committing for the first time to a universal agreement to cut greenhouse gas emissions and to avoid the most dangerous effects of climate change at crunch UN talks in Paris.  After 20 years of fraught meetings, including the past two weeks spent in an exhibition hall on the outskirts of Paris, negotiators from nearly 200 countries signed on to a deal on Saturday evening that set ambitious goals to limit temperature rise and to hold governments to account for reaching those targets.  After an anxious two-hour wait for the final plenary session to begin, Laurent Fabius, the French foreign minister, who was chairing the meeting, invited delegates to adopt the agreement. After looking up briefly, he brought down the gavel to widespread applause and cheering, signifying the deal had been formally agreed. “It is a small gavel but I think it can do a great job,” he said once the applause had died down.  Related: Paris climate deal: key points at a glance  François Hollande, the French president, appealed to negotiators to approve the 31-page text, and said countries had a rare chance to make history. “We are at a decisive point in time,” he said.  Fabius said: “It is my deep conviction that we have come up with an ambitious and balanced agreement. Today it is a moment of truth.”  The US president, Barack Obama, hailed the historic deal, tweeting:  This is huge: Almost every country in the world just signed on to the #ParisAgreement on climate change—thanks to American leadership.  Miguel Arias Cañete, the EU’s climate commissioner, said: “This is a success for the high ambition coalition”, referring to a group of more than 100 developed and developing nations pulled together by the EU and the leaders of some of the small island states, and those most vulnerable to climate change.  “This was the last chance [for the UN process],” he added, “and we have taken it.” He said that, with the agreement in place, the most important work now needed to be done. “Now it is about implementation. We need to have the policies. The EU has policies, and everyone needs to have policies [to put the agreement into practice].”  Al Gore, who was in the hall and appeared visibly moved when the agreement was gavelled in, said the accord would have a powerful effect on the economy.  “This universal and ambitious agreement sends a clear signal to governments, businesses, and investors everywhere: the transformation of our global economy from one fueled by dirty energy to one fueled by sustainable economic growth is now firmly and inevitably underway,” Gore said in a statement.  “No agreement is perfect, and this one must be strengthened over time, but groups across every sector of society will now begin to reduce dangerous carbon pollution through the framework of this agreement.”  Six years after the chaotic collapse of the Copenhagen climate summit, the agreement now known as the Paris Outcome for the first time commits rich countries, rising economies and some of the poorest countries to work together to fight climate change.  Under the deal, adopted by consensus, all countries agreed to reduce emissions. Rich countries agreed to raise $100bn (£66bn) a year by 2020 to help poor countries transform their economies. The overall agreement is legally binding, but some elements – including the pledges to curb emissions by individual countries and the climate finance elements – are not.  Related: Paris climate talks: World inches towards historic climate deal – live  Government and business leaders said the agreement, which set a new goal to by the end of the century, sent a powerful signal to business that the fossil fuel era was coming to an end.  The International Investors Group on Climate Change, a network managing €13tn of assets, said the decision would help trigger a shift away from fossil fuels and encourage greater investments in renewable energy  “Investors across Europe will now have the confidence to do much more to address the risks arising from high carbon assets and to seek opportunities linked to the low carbon transition already transforming the world’s energy system and infrastructure,” the group said.  Jennifer Morgan, of the environmental think tank the World Resources Institute, said the long term goal was “transformational” and “sends signals into the heart of the markets”.  The deal set a high aspirational goal to limit warming below 2C and strive to keep temperatures at 1.5C above pre-industrial levels – a far more ambitious target than expected, and a key demand of vulnerable countries.  It incorporates previous commitments from 186 countries to reduce emissions, which on their own would only hold warming to between 2.7C and 3C.  But it sets out procedures for review at regular intervals to deepen emissions cuts, with countries aiming to peak global greenhouse gas emissions as soon as possible, and then rapidly scale down in the second half of this century.  Critics said the agreement would still condemn hundreds of million of people living in low-lying coastal areas and small islands. But supporters said the negotiations took a significant step forward in getting countries to act together on a global challenge of immense complexity, and in sending a signal to global markets.  Saturday’s agreement was the product of years of preparation, two weeks of intense negotiations, capped off by three sleepless nights, with Barack Obama and Hollande phoning other leaders to bring them on side with the deal.  Accounts from behind the closed doors of negotiating session described tense exchanges between oil-producing countries, such as Saudi Arabia and Russia, and a rapidly constituted US- and Europe-backed High Ambition Coalition, which kept up the pressure for a strong temperature goal and regular reviews of emission-cutting plans.  #ParisAgreement is adopted in #Paris at #COP21! #GoCOP21 pic.twitter.com/9wCxyshWa7  The French hosts also won praise from negotiators for using a mixture of informal huddles, or indabas, and traditional shuttle diplomacy to bring the deal home.  The text commits countries to peak greenhouse gas emissions as soon as possible, and to seek a balance between human-caused emissions and removals by carbon sinks.  “This means bringing down greenhouse gas emissions to net zero within a few decades,” said John Schellnhuber, director of the Potsdam Institute for Climate Impact Research, and a climate adviser to the Vatican.  But he added that countries would have to move aggressively, peaking before 2030 and eliminating emissions by 2050 through reforestation and technologies such as carbon capture and storage.  For vulnerable countries, the high ambition of the 1.5C goal was offset by the weakening of the agreement when it came to dealing with irreparable damage of climate change.  Negotiators and campaigners said pressure from the US and European Union stripped the agreement of language that would have opened up new sources of funding for small islands and low-lying states that could experience irreversible damage due to climate change.  “The idea of even discussing loss and damage now or in the future was off limits. The Americans told us it would kill the COP,” said Leisha Beardmore, the chief negotiator for the Seychelles. “They have always been telling us: ‘Don’t even say that’.”  Related: Grand promises of Paris climate deal undermined by squalid retrenchments  Even so, campaign groups were broadly positive about the outcome. Given intense pressure from oil-producing countries, negotiators managed to craft a text that was far more ambitious than expected.  The universal nature of the agreement was a radical departure from the Kyoto Protocol, the 1997 agreement that drew sharp divisions between the obligations of wealthy and developing countries but ultimately failed to lower emissions.  Unlike Kyoto, the agreement reached on Saturday depends on political will, with countries setting their own climate action plans.  Rich countries promised that by 2025 they would set a new goal for climate finance “from a floor of $100bn per year”, the figure first pledged at the Copenhagen climate talks six years ago. However, the commitment was offered as a non-binding decision that accompanied the binding text.  All the countries agreed on demands from the US and European Union for five-year reviews of their emissions reductions – an exercise that had been resisted by China.
Two decades of talks have come to this: an ambitious agreement to hold states to emissions targets – but already low-lying countries are worried