City leaders are doing more to eliminate global carbon emissions than national governments, according to Hélène Chartier of international network C40 Cities.
Chartier, whose organisation is coordinating the climate strategies of almost 100 cities around the world, said that politicians have made "very, very little" progress on climate since the 2015 Paris Agreement.
"Cities have been really leaders, especially when the nations were stuck with Trump," said Chartier, who is head of zero-carbon development at C40 Cities.
Former US president Trump was a climate sceptic who pulled his nation out of the landmark Paris Agreement, which committed signatories to limit global warming to 1.5 degrees Celsius above pre-industrial temperatures. C40 Cities is a network of megacities addressing climate change
"It was very inspiring to see the US mayors really accelerate their climate action while Trump was withdrawing the US from the Paris Agreement," added Chartier, who previously worked in the office of visionary Paris mayor Anne Hidalgo.
"Without nations, it's going to be not possible [to reach net-zero] but at least mayors can pave the way." The USA has since rejoined the Paris Agreement under new president Joe Biden.
"Sometimes urban areas are more progressive so they feel that they have more operational capacity," she added. "They have more support from their residents to accelerate the transition and help nations to go in the ...