Mayors of 12 major world cities on Monday signed a declaration vowing to buy only zero-emissions buses from 2025 and to make major areas free of fossil fuel emissions by 2030.
The mayor of Los Angeles also hit out at U.S. President Donald Trump's intention to pull America out of the Paris climate change deal.
Meeting during two days in Paris as part of the C40 cities network, the mayors of London, Paris, Los Angeles, Cape Town, Copenhagen, Barcelona, Quito, Vancouver, Mexico City, Milan, Seattle and Auckland signed the C40 Fossil-Fuel-Free Declaration.
C40 is a network of the world’s megacities committed to tackling climate change.
According to the declaration, the mayors' ultimate goal is not only to limit air pollution and counter global warming, but implement the 2015 Paris climate agreement to curb greenhouse gas emissions.
"To meet this commitment we will transform our cities through people-friendly planning policies, increase the rates of walking, cycling and the use of public and shared transport that is accessible to all citizens, reduce the number of polluting vehicles on our streets and transition away from vehicles powered by fossil fuels," they agreed.
Addressing a joint news briefing, where each mayor outlined plans for his or her city, Los Angeles mayor, Eric Garcetti, said: “Global climate change is not only real, it has an effect. It is not a matter of politics but a matter of life."
Referring to the 2015 Paris climate deal, he said: "When Trump pulled out, 382 American cities have committed to delivering the Paris Agreement goals."
The 2015 Paris Climate Conference meeting on Dec. 12 reached the first legally binding and universal agreement on climate change in over 20 years of UN negotiations.
However, the U.S. administration in August issued its first written notification to the UN that it intends to withdraw from the agreement.
Trump claimed the deal "punished" the U.S. and would cost millions of jobs.
By Hajer M'tiri in Paris