When the $100 billion commitment was made at Copenhagen in 2009, the governments of developing nations understood it to mean something specific: new and additional public grant funding, provided by wealthy countries that had produced the majority of historical greenhouse gas emissions, to help poorer countries both adapt to climate impacts they had done little to cause and develop along low-carbon pathways that their own economic circumstances made difficult to afford. That understanding was never formalised into a definition with legal force. That omission was not accidental.

What was eventually counted toward the $100 billion target, when rich countries declared it met in 2022, included loans at market rates, export credits that benefit the exporting country's industries, private finance that was mobilised by but not provided by governments, and in some cases climate-related portions of development assistance that would have been provided regardless of the commitment. Independent analyses by the OECD's own critics, by Oxfam, and by a number of developing country governments calculated the grant-equivalent value of what was actually delivered at somewhere between $19 billion and $25 billion annually — roughly one quarter of the headline figure.

I am focusing on this not because I think the precise number is the most important thing, but because the gap between what was promised and what was delivered is a microcosm of a broader pattern in climate negotiations: wealthy countries make ambitious commitments in the language of moral obligation, then discharge those commitments through mechanisms that serve their own financial and commercial interests, and then declare success in forums where the aggrieved parties lack the power to effectively contest the declaration.

The new $300 billion climate finance goal agreed at COP29 in 2024 is subject to exactly the same definitional ambiguity as its predecessor. The same coalitions are arguing about what counts. The same interests are aligned against a definition that would make the commitment genuinely costly. Unless that changes — unless developing countries acquire the negotiating leverage to enforce a definition with teeth — the new commitment will follow the same trajectory as the old one.

The physics of climate change does not care about the gap between political commitment and financial reality. The communities on the receiving end of that gap do.