Less than four hours later, the accord was approved with the bang of a gavel. A bit of diplomatic finesse had excised the troublesome word and helped clinch a historic agreement.
The formal adoption of the accord on Sunday was greeted with applause and cheers by thousands of weary delegates to the climate talks in Paris. But the happy conclusion was preceded by days and weeks of tough bargaining, along with occasional flashes of drama.
Over the 13 days of the climate talks, and for months prior to it, negotiators faced the daunting task of forging consensus among government officials from nearly 200 countries - some of whom had been initially sceptical or even hostile to parts of the proposal.
US and European officials prepared the ground for an agreement during months of heavy lobbying and deal-making in scattered capitals around the globe. But while the talks were far calmer than past climate negotiations, closing the deal was at times a diplomatic high-wire act, the success of which was never assured until the final moments.
"It took hard work, grit and guts," said Jennifer Morgan, director of the climate programme at the World Resources Institute.
Diplomats and observers who witnessed the proceedings from close range credited a handful of French, UN and US officials who worked tirelessly over two weeks to keep the negotiations on track. During the most difficult phases. With French prestige on the line, Fabius and Laurence Tubiana, France's Ambassador to the United Nations on climate change, kept a tight rein on the proceedings to prevent minor disputes from turning into revolts, which has happened famously in the past.
Diplomats worked feverishly to ensure that many of the key struggles were resolved before the conference began.
Obama Administration officials pushed hard for the unusual "bottom-up" design of the draft climate accord, in which each country would submit its own, individualised plan for reducing or limiting emissions from fossil-fuel burning.
The pledges would be non-binding, but for the first time, all countries, rich and poor, would be asked to make a contribution.
By the second week of the talks, 186 capitals had done so.
A key breakthrough, diplomats said, was the US-Chinese agreement in November 2014 to jointly announce ambitious pledges to reduce their own countries' emissions, setting an example for others.
The hard bargaining began midway through the second week. The US team struggled to fend off demands from small island states and other poorer countries for guaranteed "loss and damage" compensation, essentially payment for negative impacts of climate change. But the Obama Administration would not contemplate such an open-ended financial obligation that Congress would have to approve and US citizens would have to pay for.
Kerry sought to assuage the island states' concerns by announcing a doubling of US grants, to roughly US$800 million ($1.17 billion) a year, to help poorer countries harden their infrastructure against the effects of rising sea levels.
India and China expressed support for the latest draft text on the Saturday, as did Saudi Arabia, a country that has played a spoiler role in previous talks. Delegations began to push back against suggestions for further changes to the accord for fear that the agreement would unravel.
Yet, US officials discovered the tiny revision that threatened to derail the negotiations in the talks' waning hours. The substitution of "shall" for "should" in a section that spelled out financial obligations was a potential deal-breaker. Had someone slipped in the language in an attempt to sabotage the deal?
Kerry's message to Fabius: "Either it changes, or President Obama and the United States will not be able to support this agreement".
More hours passed as the Kerry team tried to investigate how the wording had been changed and whether they could fix the text without a risky reopening of the proposal for further debate.
US and French officials decided together that the word change had been accidental. As such, it could be handled as an ordinary typographical error and erased at the discretion of the conference leader, without a risky reopening of the proposal for further debate.
The full assembly was convened to give a final okay to the climate deal. A list of technical corrections was read and approved without debate.
Ninety minutes later, the Paris climate agreement, now whole, was declared adopted.
