“WE’VE shown what’s possible when the world stands as one,” declared Barack Obama after UN climate talks in Paris ended with an agreement on December 12th. “Our collective effort is worth more than the sum of our individual effort,” said Laurent Fabius, France’s foreign minister, who oversaw the talks. “I can go back home to my people and say we now have a pathway to survival,” said Tony de Brum, the Marshall Islands’ foreign minister, voicing an opinion shared in other low-lying spots where people are terrified of rising sea levels.
The deal inspiring these eulogies was indeed stronger than had been expected. The 195 countries at the meeting agreed on the goal of keeping the increase in the global average temperature to “well below 2°C above pre-industrial levels and pursuing efforts to limit the temperature increase to 1.5°C above pre-industrial levels”. They will also pursue a goal of zero net emissions—removing as much greenhouse gas from the atmosphere as is being added to it—by the second half of the century.
The main sticking points were deciding who should do what—and who should pay. The UNFCCC, which dates from the 1992 Rio Earth Summit, calls on nations to act “in accordance with their common but differentiated responsibilities”. This “differentiation”, which distinguishes between rich countries and the rest, was a feature of the UNFCCC’s first offspring, the ill-fated Kyoto protocol. That committed developed countries—responsible for almost all greenhouse-gas emissions to that point—to emit less but demanded almost nothing of developing ones. For big developing economies, maintaining this distinction has long been a priority.