UN Secretary-General António Guterres has called for governments to “go all-out” on the energy transition by ensuring their new national climate plans help increase clarity and certainty about the switch to renewables.

In a major speech making the case for the “unstoppable” shift from fossil fuels towards renewables, Guterres urged policymakers around the world to supercharge the new “clean energy era” despite geopolitical turmoil.

“Too often, governments send mixed messages,” he said. “Bold renewable targets on one day, new fossil fuel subsidies and expansions the next.”

The new nationally determined contributions (NDCs) must send the right signals and be supported by policies that show the clean energy future is both “inevitable” and “investable”, the UN chief added.

September deadline for “ambitious” NDCs

Guterres has invited world leaders to present their NDCs at a high-level summit due to take place on September 24 in New York on the sidelines of the UN General Assembly.

Only 30 of the 195 signatories to the Paris Agreement have submitted their NDCs, although the UN had originally set a February deadline. Some of the biggest carbon emitters, including China, the European Union and India, have yet to publish their updated climate plans with an emission reduction target for 2035.

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“The reality is that we prefer to prioritise high-quality and ambitious NDCs rather than having countries rush and prepare NDCs that are low-ambition and do not have the full buy-in of all stakeholders in the economy,” a senior UN official told reporters on Monday.

If countries present their climate plans by the September event, there will still be time for the UN climate body to produce a synthesis report assessing the collective impact of the new pledges ahead of COP30, the official added. Climate Home understands that the report is expected to be published in the last week of October.

Supporting Guterres’ call, Brazil’s COP30 president André Corrêa do Lago said NDCs “must go beyond ambition”.

“They must become climate plans that create jobs, reduce inequalities, and bring prosperity to all,” he added in an email statement. “Inclusion is not an accessory to climate ambition – it is its very economic and political strength.”

“Not fast enough”

In his speech, Guterres said leaving fossil fuels behind and doubling down on investment in renewables makes economic sense, boosts energy security and represents a “game-changer” for the hundreds of millions of people still living without electricity.

Solar and wind are now almost always the least expensive – and fastest – option for new electricity generation, said a new UN report published alongside Guterres’ address.

Thanks to plummeting costs, growth in clean energy has been sky-rocketing, with renewables providing 92.5% of all new electricity capacity in 2024. But despite that, renewables have yet to make a significant dent in replacing fossil fuels, which still accounted for 60% of the global power mix last year, according to the International Energy Agency (IEA).

“The transition is not yet fast enough or fair enough,” said Guterres, who underlined that investment in renewables remains highly concentrate