A global accord for taming global warming, sealed at UN talks in Paris on Saturday, represents a potential body-blow to the fossil-fuel business, Greenpeace and other prominent environment groups said.
"The wheel of climate action turns slowly, but in Paris it has turned. This deal puts the fossil-fuel industry on the wrong side of history," Greenpeace International executive director Kumi Naidoo said.
"Today the human race has joined in a common cause, but it's what happens after this conference that really matters," he added.
Greenpeace, major green groups and climate change researchers gave a mixed report card on the many details in the accord, endorsed by ministers from 195 nations at the talks.
But they emphasised that by striving to limit warming to 1.5 degrees C (2.7 degrees Fahrenheit) over pre-Industrial Revolution temperatures, the agreement would have an impact.
"That single number, and the new goal of net zero emissions by the second half of this century, will cause consternation in the boardrooms of coal companies and the palaces of oil-exporting states," Naidoo predicted.
Researchers and activists declared that the agreement would make history.
"The Paris Agreement marks a new form of international cooperation -- one where developed and developing countries are united by a common and fair framework," said Jennifer Morgan, global director of the climate programme at the World Resources Institute (WRI), a Washington-based think tank.
"The agreement is both ambitious and powered by the voices of the most vulnerable."
May Boeve, executive director of 350.org, an organisation pressing financial institutions to divest from fossil fuels, also said the 1.5C reference was key.
"This marks the end of the era of fossil fuels. There is no way to meet the targets laid out in this agreement without keeping coal, oil and gas in the ground," Boeve said.
Tim Gore, policy director at British charity Oxfam, said a provision aiming to cap global warming at 1.5C would require an unprecedented global effort.
The emissions reduction plans submitted by some 185 nations ahead of the talks have put Earth on a path to least about 3.0C degrees of warming.
"The 1.5C degree target is an important moral victory, but -- as we have heard -- it may yet ring hollow unless we see significant increases in action in the years ahead," Gore said.
Morgan echoed his warning, noting nations around the global must accelerate the pace of change.
"World leaders need to build on the momentum created by the Paris moment and move even faster and further toward a decarbonised economy."
More critical, Friends of the Earth said prosperous nations had pushed through an empty accord.
"Rich countries have moved the goal posts so far that we are left with a sham of a deal in Paris," said Sara Shaw, an activist with Friends of the Earth International.
"Through piecemeal pledges and bullying tactics, rich countries have pushed through a very bad deal."