Not forgetting the Paris Accords: cities will be key to fight climate change in the Trump era

Despite the United States’ (second) withdrawal from the Paris Agreement, US cities are choosing to step forward and maintain their commitment to honouring international climate goals, as they did during Donald Trump’s first term. In an increasingly urban world and amid the international political vacuum, cities are models of climate ambition, and they need backing from national and international levels of government. 

This article was previously published in El País.

On January 20^th, 2025, Donald Trump was sworn in as the 47^th president of the United States. Wasting no time, he set to signing executive orders that confirmed much of what he had promised during his election campaign, including the United States’ withdrawal from the Paris Agreement. The fact that the second largest emitter of greenhouse gases into the atmosphere is abandoning the primary multilateral tool to limit them and therefore to minimise the negative effects of climate change globally is, overall, not good news for the world. But what of climate action inside the United States?

It is not the first time Trump has been president, nor is it the first time he has pulled his country out of the Paris Agreement. Then, as now, the climate community waited with bated breath. Despite all his policies deviating from or running directly counter to the international climate agenda, climate action in the United States suffered less than initial forecasts had predicted. And one of the explanations for that is that many cities in the country decided they would step forward and meet the goals of the Paris Agreement locally, regardless of their federal government.

Why are cities key to climate action? While cities cover just 3% of the Earth’s surface, they are responsible for around 70% of greenhouse gas emissions. That makes them not just part of the problem, but also a key part of the solution. What’s more, because they are more flexible than state governments when it comes to implementing local regulations to reduce emissions and promote the use of renewable energies, they have greater scope for experimentation and innovation on climate policy. In a world that by 2050 will have 68% of its population living in cities, municipal governments can play a transformative role in climate action as they hold responsibilities in key areas of public policy such as urban planning, infrastructure management, building regulation and promoting sustainable mobility. This window of opportunity has a strategic dimension particularly in the cities of the Global South, where the bulk of the current process of urbanisation is taking place.

When Trump announced the decision to withdraw the United States from the Paris Agreement in 2017 – which would lead to its formal exit on November 4^th, 2020 – he did so declaring he had been elected to represent the people of Pittsburgh, not Paris. As irony would have it – and in keeping with our turbulent times – the then mayor of Pittsburgh, Bill Peduto, promptly spoke out on behalf of his city to condemn the federal government’s decision, reiterating its commitment to honouring international climate goals. His was not the only city to step up to the plate. During that first term, nearly 300 US counties and cities, including New York, San Francisco, Los Angeles and Chicago, came together in initiatives such as We Are Still In and promoted local climate policies of their own. In some states, businesses and municipal governments kept up their investments in green infrastructure and sustainable transport. Some cities also challenged the Trump administration’s commitment to fossil fuels by investing in renewables. US cities ultimately retained climate leadership at national and international level in those years, demonstrating that climate action could move forward even without federal government backing. This meant the United States could swiftly rejoin the Paris Agreement in 2021, when Joe Biden took up the presidency and restored environmental policies at national level.

Back in the present, shortly after Trump signed the executive order, the multimillionaire Michael R. Bloomberg, the United Nations secretary-general’s special envoy on climate ambition and solutions, announced via his philanthropic foundation that he would step in for the United States and maintain funding for the United Nations Framework Convention on Climate Change (UNFCCC). It is a significant contribution considering the United States usually covers 22% of the UNFCCC secretariat’s budget. This decision, repeating a precedent set during Trump’s first term, also supports the US cities, states and businesses working to meet international climate goals. According to a study by the University of Maryland, by 2035 climate leadership from US non-federal actors could achieve a 54-62% reduction in greenhouse gas emissions relative to 2005 levels.

The growing importance of philanthropic foundations and private sector actors in climate action is essential, all the more so in a context of inaction at national level. But cities should be backed by the other levels of government – national and international – and by government actors with political legitimacy and experience on the ground. Amid gridlocks in the multilateral system and the questioning of the climate agenda in various countries around the world, cities are models of climate ambition with an eye on the public interest. This is particularly true in the Global South, where cities must simultaneously tackle the growing impacts of climate change and deficits of infrastructure and services. Against a backdrop of geopolitical tensions and international leadership vacuums, the European Union should also take note, recognising essential partners in their own cities, both with a view to promoting the European Green Deal and in boosting cooperation with cities in the Global South.

Keywords: climate, Paris Accords, cities, Trump, United States, greenhouse gases, emissions, UNFCCC

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