Paris (France) (AFP) - UN chief Antonio Guterres called Tuesday for faster action on global warming, challenging AI firms to “come clean” about their environmental footprint and warning that fossil fuels were driving climate and energy crises.

As Europe bakes under a second heatwave in as many months, Guterres delivered a speech in London that painted a stark picture of a planet that has just endured its 11 hottest years on record.

“Climate chaos is accelerating before our eyes,” Guterres said, while the energy crisis, fuelled by war in the Middle East, is “exposing the folly of a world hooked on hydrocarbons”.

“It is clear that our world is facing a Tale of Two Crises,” Guterres said, referencing the 19th century British writer Charles Dickens’ “A Tale of Two Cities”.

“On the surface, these crises may seem separate. But they share the same destructive origin: Fossil fuels,” he said at London Climate Action Week, an annual gathering of policymakers, company executives and NGOs.

Guterres announced new initiatives to combat methane emissions and address concerns over the environmental footprint of energy-hungry data centres.

The growing energy, water and land use of data centres – vast server warehouses powering AI and other digital services – is putting pressure on local communities and the environment.

A UN study earlier this month found that the facilities consumed more electricity than all but 10 countries in 2025. By 2030, they could use more power than all but five countries, the study found.

Guterres launched an AI Environmental Transparency Initiative, urging every major artificial intelligence company to measure and publicly disclose their environmental impact as well as commit to powering every data centre with renewable energy by 2030.

“It is time to come clean,” Guterres said. “If AI is to help build a better future, it must be honest about what it costs us now.”

- ‘Far greater urgency’ -

Guterres warned that the world was “dangerously” off track in efforts to reach the global goal of achieving net zero emissions by 2050.

Countries agreed to pursue efforts to limit warming to 1.5C above preindustrial levels under the 2015 Paris Agreement, but scientists now say that threshold could be breached by about 2030.

“We must act with far greater urgency to strictly limit the magnitude and duration of any overshoot beyond 1.5C,” Guterres said.

Rising temperatures are pushing the world closer to “catastrophic tipping points”, he said.

The United Nations Scientific Advisory Board released a report outlining the dangers of crossing irreversible tipping points, from ice melt that would further raise sea levels to the collapse of coral reefs and Amazon decline.

The UN chief’s warning came as Europe’s latest heatwave brought record temperatures in France and seared other European countries this week.

- ‘Best and worst of times’ -

Guterres called for a rapid cut in CO2 emissions from oil, gas and coal – the main driver of long-term warming, which remains in the atmosphere for centuries.

He urged governments to tax the windfall profits of oil and gas giants and said the world has a “clean way out” of fossil fuels through accelerating the transition to cheaper renewable energy.

The UN chief also called for renewed efforts to reduce methane emissions, which account for one-third of warming and are about 80 times more potent than CO2 but break down in the atmosphere in a decade or two.

Guterres said the agriculture and waste sectors must take steps to curb their methane output but he put a “special focus” on the fossil fuel industry to “do what is long overdue”.

Around 70 percent of oil and gas methane emissions can be eliminated with existing technology, but some 167 billion cubic metres of gas were flared in 2025 alone, as much as Africa consumes in a year, he said.

He called on governments to set a “new global standard” for the oil and gas sector that would lead to “near-zero” methane emissions.

“This is indeed the best of times and the worst of times. The worst because climate impacts are intensifying, tipping points are looming, and the energy crisis has exposed the deep risks of dependence on fossil fuels,” he said.

“But also the best because the renewables revolution is well underway.”