UNITED NATIONS: Outgoing UN chief Antonio Guterres hailed the “unstoppable” rise of renewable energy and urged countries to develop firm plans to quit fossil fuels as he opened his final climate meeting Wednesday at the world organization’s New York headquarters.

Speaking a day after denouncing “Big Oil” for treating the atmosphere like an “open sewer,” the 77-year-old secretary-general used his summit speech to sound a note of hope.

“Renewables are the cheapest, fastest, and most secure source of new electricity almost everywhere,” he said. “Clean energy has gone from alternative to unstoppable.”

He called on countries to lift their emissions cutting targets and release concrete plans to quit fossil fuels — a cause given a boost by Germany, Europe’s biggest economy, which issued its roadmap hours before Guterres’ swansong address as a summit convener.

Germany is the third country to do so, after France and the Netherlands.

“We are the first generation with the tools to end the fossil fuel age — and the last who can avert climate catastrophe,” Guterres concluded.

His remarks at the “High-level Event on Climate Action and the Just Transition” are set to be followed by Turkish President Recep Tayyip Erdogan and Australian Prime Minister Anthony Albanese.

- ‘Extraordinary climate champion’ -

The two countries are co-hosting COP31 climate talks in Antalya in November in an unusual arrangement, with Australia running the talks but Turkiye hosting the event and rallying support for voluntary pledges.

The stakes are clearer than ever, as the impacts of climate change surge around the world — from heat waves and wildfires in Europe to catastrophic flooding in Nepal and Tibet triggered by a glacier collapse.

Extreme weather events are set to worsen with a strengthening El Nino cycle that has already tied a record for intensity, months from its peak.

And the world is set to shoot past — at least temporarily — 1.5C of warming. Scientists say temperature increases above that level will bring on worse climate-linked catastrophes.

Guterres made climate change a defining issue of his nine-year-tenure that ends on December 31.

“Guterres is an extraordinary climate champion,” Rachel Cleetus of the nonprofit Union of Concerned Scientists told AFP, praising the former Portuguese prime minister for using his position “to elevate the voices of the less powerful and highlight the need for climate justice.”

- Emissions cuts, financing, electrification -

The meeting agenda calls on leaders to focus on areas like accelerating action to green their economies and mobilizing financing for developing countries to help them achieve their carbon goals and build resilience against a warming world.

Momentum is also gathering for electrification: switching combustion-based systems, like in heating and vehicles, to electricity.

Turkiye has advanced a “35x35” target to increase electricity’s share of global energy consumption to 35 percent by 2035. However, it has not specified that the electricity should be generated by renewables, which is key to tackling climate change.

Global renewable power capacity grew by a record amount last year. But as energy demand increases — not least from AI data centers and air conditioning in a warming world — clean energy is not growing fast enough to displace fossil fuels.

Climate Week and the UN General Assembly “is always a good moment for incoming COP presidencies to really make clear what are the expectations for the COP,” Linda Kalcher, executive director of the Strategic Perspectives think tank, told AFP.

At the start of the week, Albanese extolled his nation’s rising share of renewables in its energy mix.

Yet his climate change and energy minister Chris Bowen is traveling to India and Saudi Arabia this week for talks on strengthening Australia’s oil supplies.

Pledges for Nepal — where thousands remain missing after a devastating August 26 flood — could also feature.

Nepalese Foreign Minister Shisir Khanal recently told Kantipur TV that financial support “is not a matter of charity; it is a matter of legal and moral liability” for his climate-vulnerable country, which produces negligible emissions.