BARCELONA, February 10 (WNM/Reuters/Megan Rowling) – Around the world, front-runner cities are testing new ways to cut their emissions faster and protect residents from floods, heatwaves and rising sea levels, while improving their quality of life in the bargain.

According to advocacy group The Climate Mobilization, which is trying to persuade governments to respond urgently to climate change, more than 1,300 local governments in about 25 countries have now declared a "climate emergency".

But in many cases, translating that into concrete action is an uphill struggle, not least because it requires a wholesale shake-up of established methods of working, climate experts say.

"Emergency declarations, if they are real, can be very powerful tools, depending on the kind of governance and legal framework you're in," said Michael Berkowitz, a founding principal of Resilient Cities Catalyst, a nonprofit consultancy, to Reuters.

In countries such as the United States, such declarations can focus attention, unlock resources and help cut through red tape, said the former head of the 100 Resilient Cities network.

But to radically shrink a city's carbon footprint will take sustained effort "over a couple of political cycles", he noted.

For instance, London Mayor Sadiq Khan, a Labour politician, has pushed on with cleaner transport policies started by his Conservative predecessor Boris Johnson, now Britain's prime minister, including low emission zones and cycling infrastructure, Berkowitz said.

Another way to protect green policies is for local governments to involve businesses and civil society groups as equal partners in the push to tackle climate change, he said, citing the port city of Rotterdam as a good example.

"If it's just mayors with small coalitions pounding the table, that feels like hollow political statements," he added.