Some of the world’s major cities, including London, Paris and New York City, are no longer increasing their greenhouse gas emissions.
New analysis reveals 27 cities, representing 54 million people and $6 trillion (£4.6tn) in GDP, saw carbon emissions peak in 2012.
Emissions then fell by 2% every year on average while their economies grew by 3% annually.
The main drivers for cities to achieve peak emissions were decarbonisation of the power grid, building energy efficiency, providing cleaner and affordable alternatives to private cars and reduce waste and boosting recycling rates, according to C40 Cities, a network of cities acting as leaders in combating climate change.
Other cities that have also seen a peak in emissions are Barcelona, Basel, Berlin, Boston, Chicago, Copenhagen, Heidelberg, Los Angeles, Madrid, Melbourne, Milan, Montréal, New Orleans, Oslo, Philadelphia, Portland, Rome, San Francisco, Stockholm, Sydney, Toronto, Vancouver, Warsaw and Washington DC.
To date, mayors of more than 60 C40 cities have committed to develop and begin implementing ambitious climate action plans by 2020 that go beyond national commitments to achieve the highest goals of the Paris Agreement at the local level.
The plans are expected to see many more cities achieve peak emissions over the coming years and become emissions neutral by 2050.
The news was announced at the Global Climate Action Summit in San Francisco this week.