Much more of the fuel tax proceeds, Mr. Kammen said, could have been used to lower the prices of electric vehicles, including taxis, to help make it more affordable for people to commute from areas with no public transportation links. Or it could have been used to develop more charging stations or subsidize big batteries to enable taxis to do long trips.
“So while President Macron has highlighted the need for funds to invest in clean energy, that is not actually what was planned,” Mr. Kammen said.
Politically, the backlash came from those who could least afford to give up their cars — small-town and suburban residents priced out of big cities and unhappy with Mr. Macron on a host of other issues already. It did not help that Mr. Macron had lowered taxes on the rich in one of his earliest tax code changes.
Like most policy measures, a tax on fossil fuels can be painful if badly constructed.
“This situation illustrates how equity and fairness considerations have to be built into the design of such policies,” Alden Meyer, policy director at the Union of Concerned Scientists, said by email from Katowice, Poland, where United Nations climate talks are underway.
Others agreed. “There is a consensus among economists who have said that to fight against the warming climate, there must be a price put on carbon, but they underestimated the social repercussions that could have,” said Jean-Marie Chevalier, a French economist and professor emeritus at the University Paris-Dauphine.
“The people in the street do not give a damn about the energy transition,” said Mr. Chevalier, who worked for many years with Cambridge Energy Research Associates, whose clients include business and governments worldwide.
In Canada, conservatives have pledged to undo Prime Minister Justin Trudeau’s plans for a national carbon tax. Only six of 10 provinces are going along with his plan.