The draft Paris climate agreement represents "the beginning of the end of the fossil fuel era", according to Kumi Naidoo, executive director at Greenpeace International.
“We’re not out of the hole yet, but there are enough hooks in there to help us get out of it,” he said.
“The wheel of climate action turns slowly, but in Paris it has turned, and put the fossil fuel industry on the wrong side of history,” he told a press briefing, saying it would “cause consternation” in oil and coal company boardrooms and “the palaces of oil-producing states”.
Responding to the draft circulated by France before delegates were given a break for lunch, Mr Naidoo said the commitment to hold the rise in global temperatures "well below 2 degrees Celsius", even as low as 1.5 degrees, "effectively means that we have to phase out fossil fuels by 2050".
He reaffirmed that climate activists, who had already stopped the Keystone XL pipeline in the US and "kicked Shell out of the Arctic", would be stepping up civil disobedience campaigns worldwide in 2016. "Paris is a stop on a long journey, but we're now in with a serious chance to succeed."
Tim Gore, head of food and climate policy at Oxfam, said the inclusion of efforts to limit global warming at 1.5 degrees was an "important moral victory" for people in the most vulnerable countries. "We know that Paris will be the floor, not the ceiling, for climate action".
Mohamed Adow, head of global climate policy at Christian Aid, said the draft agreement -- now widely expected to be "gavelled through" later this evening - "ushers in a new era and means that the transition to a low-carbon future inevitable. That message is quite clear."
Referring to the commitment to review pledges already made by 185 countries to cut their greenhouse gas emissions every five years, starting in 2018, he said: “The baby conceived [at COP17]in Durban has now been born and, like any infant, needs to be nurtured to grow strong.”
Mr Adow, who hails from a pastoralist background in Kenya, said the 1.5-degree target "can only be achieved if everyone -- businesses, stock exchanges, oil state palaces ride the climate wave from Paris", adding that it should "echo across the world in all those places investing in dirty energy".
But Asad Rehman, director of Friends of the Earth UK, insisted that the draft agreement meant that "we are on track for a 3-degree world" because the means to achieve long-term goal were too weak. "The ship is going down, and the poor are being denied a place in the lifeboats," he said.
Lidy Nacpil, a climate activist from the Philippines, said the draft was full of "nice words without much meaning", which had been "even more diluted" in the negotiations.
Even the pledge of at least $100 billion per year in aid for poorer countries didn’t mean much as only $10 billion had actually been raised.
Ethiopian activist Azeb Girmai, speaking for LDC Watch, which keeps an eye on the least developed countries in Africa and elsewhere, described it as "the saddest day for all the poor people in the world facing loss and damage day-in and day-out" while their representatives in Paris were "bullied" by rich countries.
Erich Pica, president of Friends of the Earth US, referred to the exclusion of any claims for compensation by poor countries suffering loss and damage due to climate change, saying the "US fingerprints are all over it", even though island nations "are going to be extinct because of centuries of pollution by the US".
The Global Indigenous Caucus, which had worked hard in Paris to ensure that human rights would be a key element, said it was very disappointed. But it recognised that this would be a long struggle. “What happens to us will eventually happen to everyone. They have to save us if they’re to save themselves.”