In an open letter released on Tuesday, 36 former presidents and prime ministers from nations ranging from Sweden to the Seychelles urged the adoption of so-called "polluter profit taxes" on oil, gas, and coal companies. The initiative aims to hold fossil fuel firms financially accountable for the environmental and social damage caused by their operations.
The Club de Madrid, which coordinated the effort, said the taxes are essential both to accelerate the global transition to renewable energy and to support populations most vulnerable to climate-related disasters.
"Taxing fossil fuel profits is not just a question of fairness," said Rebecca Newsom of Greenpeace International, supporting the former leaders' proposal. "It is a crucial step to alleviate the economic strain of the climate crisis on ordinary people — from rising food prices to higher energy bills and insurance costs."
Political headwinds complicate climate pledges
The letter coincides with this week's UN General Assembly in New York, where climate policy has become increasingly contested. Skepticism from some world leaders threatens to weaken international momentum. During his UNGA address, US President Donald Trump dismissed climate change as "the greatest con job," describing carbon footprints as a "hoax," highlighting the political challenges facing global action.
Meanwhile, reports indicate that top fossil fuel-producing nations plan to increase coal, oil, and gas production well beyond levels consistent with the Paris Agreement's 1.5°C target. Even under the more lenient 2°C limit, planned production exceeds safe levels by more than 75%.
Funding climate action through windfall taxes
The former leaders' proposal points to past success: during the 2022 oil and gas price crisis, temporary windfall taxes raised billions. A permanent tax — modest on normal profits but heavier on windfall gains — could generate up to €340 billion ($400 billion) in its first year, they argue.
Public support appears strong. A 2025 survey by Greenpeace and Oxfam across 13 countries, covering more than half the global population, found that eight in ten respondents back taxing fossil fuel companies to address climate damages.
With COP30 in Brazil later this year and negotiations on a UN Global Tax Convention planned for November, proponents hope the call for polluter taxes will influence international climate financing. Observers say whether governments implement such measures could serve as a clear test of their commitment to the Paris climate goals.
"The climate crisis is a defining challenge of our time," the letter concludes. "Communities worldwide are facing extreme weather, biodiversity loss, and economic disruption. Millions, particularly the most vulnerable, are losing their homes, livelihoods, and lives — while air pollution from fossil fuels alone causes an estimated 4.2 million premature deaths each year."