Paris (France) (AFP) - UN chief Antonio Guterres challenged AI firms on Tuesday to disclose their growing environmental footprint as part of a push for faster global action to curb climate change.

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 pushed for a rapid transition to renewable energy while announcing new initiatives to combat methane emissions and address concerns over the environmental impact 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.

“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.”

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.

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.

About 30 percent of the electricity consumed by data centres comes from coal, followed by renewables at 27 percent, natural gas at 26 percent and nuclear at 15 percent, according to the International Energy Agency.

A coalition of dozens of cities announced Tuesday a “Global Urban Data Centres Pact” aiming to ensure that the facilities are built in a way that minimises their environmental impact.

“AI and digital infrastructure will play a major role in the future prosperity of cities around the world, but residents are right to expect growth to be managed responsibly,” said London Mayor Sadiq Khan.

- ‘Far greater urgency’ -

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

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.

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

- ‘Long overdue’ -

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.

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.