The world needs to urgently start investing trillions of dollars in the green transition, the United Nations climate chief said on Friday, warning that finance was the "make-or-break" factor in the battle to curb global heating.
Countries at last year's COP28 UN climate negotiations in Dubai agreed to triple global renewables capacity this decade and "transition away" from polluting fossil fuels.
But the deal lacked important details, including on funding.
Now the world will need to come up with a clear plan to find "torrents -- not trickles -- of climate finance," UN climate chief Simon Stiell said in a speech in Baku, Azerbaijan, which will host this year's climate summit (COP29) in November.
"Whether on slashing emissions or building climate resilience, it's already blazingly obvious that finance is the make-or-break factor in the world's climate fight -- in quantity, quality, and innovation," said Stiell, who is executive secretary of the UN Framework Convention on Climate Change (UNFCCC).
"In fact, without far more finance, 2023's climate wins will quickly fizzle away into more empty promises."
In a speech which traced backwards from a vision of success in 2050 to the actions of the next two years, he said the changes over the coming decades would be "comparable in scope to the industrial revolution" or the growth of the digital economy.
The world is currently far off track in delivering on its cornerstone climate deal, agreed in Paris in 2015.
Help for emerging economies
Under the Paris Agreement, world leaders pledged to keep the rise in Earth's average temperature to "well below" 2.0 degrees Celsius above the pre-industrial level and preferably the much safer threshold of 1.5C.
The 2020s are critical for keeping that 1.5C target in view, with UN climate experts estimating that planet-heating greenhouse gas emissions need to be slashed by some 43 percent by 2030.
There is progress, with a surge in clean energy technologies like solar, wind and batteries, as well as electric vehicles.
But emissions continue to rise.
A key challenge that is likely to take centre stage at this year's climate talks in Baku, as well as meetings of the World Bank and International Monetary Fund, is how to help emerging economies manage and pay for their transition to clean energy.
Many of these nations are currently mired in debt and facing a raft of challenges, from inflation to growing climate impacts.
Developing countries, except China, face an estimated $2.4 trillion annual cost by 2030 to meet their climate and development priorities.
Stiell urged multilateral development banks to deliver "concrete actions" this year and move towards doubling or tripling their financial capacity by 2030.
'Olympian effort'
Meanwhile global warming continues, with 2023 confirmed as the hottest ever recorded and experts warning 2024 could be even hotter.
The Earth is now about 1.2C warmer than it was in the 1800s.
This is already having an accelerating impact on people and ecosystems across the planet, from stifling heatwaves and crop-wilting droughts, to devastating floods and storms.
A damning appraisal of countries' decarbonisation efforts so far, released last year, showed the world heading for catastrophic planetary heating.
Stiell conceded it would take an "Olympian effort" to get the world on track.
One key task for countries will be to outline a new round of national climate targets for 2035 ahead of a pivotal COP30 meeting, due to be held in Brazil in 2025.
These new pledges should be strengthened to align with the 1.5C goal, cover the whole economy and all greenhouse gases, Stiell said.
"The action we take in the next two years will shape how much climate-driven destruction we can avoid over the next two decades, and far beyond," he added.