UN secretary-general Antonio Guterres called on Wednesday for a “windfall” tax on the profits of fossil fuel companies to help pay for the fight against global warming, calling them the “godfathers of climate chaos”.

In a bare-knuckled speech timed for World Environment Day, Mr Guterres, who has repeatedly spoken out about the threat of climate change, said that global emissions of carbon dioxide must fall 9% each year to 2030 for the 1.5C target to be kept alive.

The burning of fossil fuels like oil, gas and coal is the main contributor to global warming caused by human activity.

He called on advanced economies in the Group of 20 countries, who are holding a summit in Brazil next month, to take the lead.

“We cannot accept a future where the rich are protected in air-conditioned bubbles, while the rest of humanity is lashed by lethal weather in unliveable lands,” Mr Guterres said.

His speech came as the UN weather agency predicted that there is an 80% chance that average global temperatures will surpass the 1.5C target laid out in the landmark Paris climate accord within the next five years.

The World Meteorological Organisation said that the global mean near-surface temperature for each year from 2024 to 2028 is expected to range between 1.1C and 1.9C hotter than at the start of the industrial era.

It also estimated that there is nearly a one in two chance – 47% – that the average global temperatures over that entire five-year span could top 1.5C, an increase from just under a one-in-three chance projected for the 2023-2027 span.

Meanwhile, the European Union’s climate service says last month marked the hottest May ever, capping 12 straight months of average monthly temperature records amid high and rising concerns about global warming.

The EU’s Copernicus climate change service, a global reference for tracking world temperatures, cited an average surface air temperature of 15.9C last month, or 1.52C higher than the estimated May average before industrial times.

Mr Guterres spoke from the American Museum of Natural History in New York in a bid to revive focus on climate change at a time when many national elections, and conflict in places like Ukraine, Gaza and Sudan this year have seized much of the international spotlight.

He repeated concerns about subsidies paid out in many countries for fossil fuels, which help keep prices low for consumers.

“Climate change is the mother of all stealth taxes paid by everyday people and vulnerable countries and communities,” he said.

“Meanwhile, the godfathers of climate chaos, the fossil fuel industry, rake in record profits and feast off trillions in taxpayer-funded subsidies.”

Mr Guterres said that global emissions of carbon dioxide must fall 9% each year to 2030 for the 1.5C target under the Paris climate accords to be kept alive.

But temperatures are “heading in the wrong direction,” he said. They rose 1C last year.

“We are playing Russian roulette with the planet. We need an exit ramp off the highway to climate hell,” Mr Guterres said, adding: “The truth is, we have control of the wheel.”

He appealed to “global finance”, alluding to banks and international financial institutions, to help contribute money, saying “innovative sources of funds” are needed.

“It’s time to put an effective price on carbon and tax the windfall profits of fossil fuel companies,” he said.

But Mr Guterres said that all countries and people must join the fight, including the developing world, such as by ending deforestation and meeting targets to double energy efficiency and triple renewables by 2030.

Some critics say Mr Guterres, which such alarmist speeches, puts too much focus on stirring emotions than focusing on science that lays out the actual threat.

But UN officials and non-governmental groups acknowledge that the secretary-general has little power beyond the “bully pulpit”, his perch at the head of the world body, to stir people, governments and business to change.