LE BOURGET, France — Representatives of 195 countries reached a landmark climate accord Saturday that would, for the first time, commit nearly every country to lowering planet-warming greenhouse gas emissions to help stave off the most drastic effects of climate change.
Delegates who have been negotiating intensely in this Paris suburb for two weeks gathered for the final plenary session where, suddenly, Foreign Minister Laurent Fabius of France asked for opposition to the deal and, hearing none, gaveled the session closed.
With that the delegates achieved what had been unreachable for two decades: a consensus on the need to move away from carbon-based fuels and a plan for the 195 nations to do so.
Though the final deal did not achieve all that environmentalists, scientists and some countries had hoped for, it set the table for further efforts to slow down the slide toward an unlivable planet.
In the end, it was an extraordinary effort at international diplomacy. Supporters of a deal argued that no less than the future of the planet was at stake, and in the days leading up to the final session, they worked relentlessly to push skeptical nations to join their ranks.
At the heart of the final deal is a breakthrough on an issue that has foiled decades of international efforts to address climate change. Traditionally, such pacts have required developed economies, such as the United States, to take action to mitigate greenhouse gas emissions, but they have exempted developing countries, such as China and India, from such action.
The new accord changes that dynamic by requiring action in some form from every country, rich or poor. The echoes of those divides persisted during the negotiations, however.
The accord was heralded by three leaders — Foreign Minister Laurent Fabius of France, President François Hollande of France and Secretary-General Ban Ki-moon of the United Nations — who helped shepherd it through the final phase of a two-year effort to forge commitments to lowering the rate in which carbon emissions are released into the atmosphere.
"Our text is the best possible balance," Fabius said, "a balance which is powerful yet delicate, which will enable each delegation, each group of countries, with his head held high, having achieved something important.