The new and greener Paris

All over Paris, streets have been dug up and cut in two, and old paving stones overturned to build dozens of miles of bike lanes. A major urban highway has been closed to cars and turned over to pedestrians. Paris is readying feverishly for an emergency that, in the minds of the city and its mayor, is already here.

The scorching summer blasted Parisians off the streets and turned the city into an eerie dystopia of what may lie ahead. The brutal heat removed any doubt, if there was one, in Mayor Anne Hidalgo’s mind: Climate change has arrived.

Paris today is like a giant construction site. By the end of the summer more than 8,000 projects, most private but all approved by the city, were underway, with historic squares like Madeleine, Bastille and Nation transformed to make them more friendly to pedestrians.

Ugly craters in the asphalt signal work on the electrical grid, the urban heating system for big buildings, the subway and regional transport, and of course the city’s miles of protected bike lanes.

The environmental results are ambiguous at best. There were around five days with elevated ozone levels, for instance, in 2014, the year Ms. Hidalgo took over; in 2018 there were from 15 to 22, depending on which part of the city you were in.

“There are fewer cars, but there is more congestion, and that can affect pollution levels,” said Paul Lecroart, an urban planning expert at the Paris regional planning agency.