Glasgow, the host city of the Cop26 climate change summit, has told leaders that efforts to stop global warming will fail unless the world's poorest see the benefits of such policies.
The plea comes as protesters are set to converge on Parliament Square in central London on Friday, urging Prime Minister Boris Johnson to take more urgent action ahead of the crucial talks to be held in November.
Giant alarm clocks will show time running out, while 100 protesters will chant that the prime minister and his chancellor, Rishi Sunak, are “missing in action”.
On Thursday, environment and energy ministers from the G20 nations made little progress on how to reach climate goals as a group of countries resisted firm commitments.
Near the sumptuous royal palace in Naples, where the meeting took place, thousands of flag-waving marchers protested against what they said was a lack of action on global warming.
Sue Atkin, leader of Glasgow City Council, ramped up the pressure ahead of Friday's protest in London by warning that the path to net zero emissions must not adversely affect the poor.
"The journey to net zero has to happen with and for our people, not to them," she told an online event marking 100 days to the key talks.
"It can't be about just telling our poorest residents what they have to give up ... (It) has to show how to take advantage of this changing world."
Ms Aitken said Glasgow was still battling social deprivation as a result of the city's painful industrial decline starting in the 1950s.
"Anything but a just transition we will come to regret," she said.
Nigel Topping, Britain's high-level climate action champion for Cop26, said failure to make sure the coming green shift was fair would derail the UN conference.
"If we don't do it inclusively, the politics will end up being against us," he said.
Cities have been at the forefront of government climate action over the past decade, with many declaring net zero emissions goals long before countries or businesses followed suit.
Today more than 750 global cities have pledged to reach net-zero emissions by the middle of the century.
London Mayor Sadiq Khan told the online event that "cities can show national governments the leadership that's required".
Providing jobs, more affordable energy, more comfortable homes and better access to carbon-absorbing green spaces for all residents - including the poor - is a key part of that push, mayors said.
Ada Colau, Barcelona's mayor, said efforts in her city to launch a new company to supply green electricity had led to both lower emissions and cheaper power for residents.
Mohammed Adjei Sowah, the mayor of Ghana's capital Accra, said his city's push to cut emissions involved recognising that informal workers make up at least 75 per cent of the city's workforce and trying to bring them into new jobs that are green and more stable.
"To ensure a truly just transition ... we cannot afford to ignore the informal sector in the things we are doing," he said.
Scores of officials from 196 countries are set to fly to Glasgow for two weeks of intense negotiations aimed at setting new targets to limit the catastrophic effects of climate change.
But climate experts accused the UK government of failing to take the talks seriously enough.
“We ask ourselves every day – where is the prime minister?” Chris Venables from the Green Alliance thinktank said.
“It’s clear that he has not grasped the scale of holding the biggest diplomatic event on UK soil since the second world war. This should be his No 1 priority.”
Bernice Lee, a research director at the Chatham House thinktank, said: “This is mission-critical - we need another round of leader-level diplomacy from Johnson.”