Nations at the UN climate summit have for the first time taken explicit aim at the use of fossil fuels.
The talks in Dubai came close to collapse but in a dramatic turn-around, nations agreed to “transition away” from coal, oil and gas.
But small islands hit hard by climate change protested, saying the deal was rushed through without them.
And it departed from earlier stronger language to “phase out fossil fuels”.
Many nations including the US, UK and European Union had pushed for a phase out from the opening of the talks.
Close to 200 nations were in the United Arab Emirates for almost two weeks to try to make progress on tackling climate change after months of record-breaking extreme weather.
Onlookers’ fears of a conflict of interest seemed confirmed when leaked documents suggested Mr Jaber had planned to use the presidency to strike business deals.
But on Wednesday Mr Jaber delivered a jubilant speech, saying the conference “should be proud of our historic achievement”.
The deal today will likely be seen as a victory for his leadership.
The gavelling of the deal itself took many delegates by surprise but was met with cheers and a standing ovation in the plenary room.
However, a representative for the Alliance of Small Island States (Aosis) – representing nations on the frontlines of climate change – took the microphone as soon as comments were open to nations.
“It seems that you just gavelled the decisions when the small island states weren’t in the room,” she said.
And she said Aosis are concerned that the key language about transitioning away from fossil fuels “potentially takes us backward rather than forward”.