Why Tripling Climate Adaptation Finance Would Still Fall Short

Even if international public funding for climate adaptation triples by 2035, it would cover only 20% to 29% of what developing countries are estimated to need that year. That is the finding of the UN Environment Programme’s November 4 Adaptation Gap Report, published days before COP31 opens in Antalya, Türkiye. Reuters’ November 6 reporting identified finance as one of the main issues heading into the summit.

Adaptation spending can pay for things that reduce damage before a flood or heat wave hits. In Rotterdam, for instance, the designers of Benthemplein water square built a public space whose sunken areas can temporarily store rainwater. The Dutch project illustrates the kind of infrastructure adaptation can involve. UNEP’s financing estimate concerns developing countries.

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What would actually triple?

At COP30 in Belém, parties called for efforts to at least triple adaptation finance by 2035. The decision left the starting amount unspecified. UNEP estimates that developed countries provided $28.2 billion to $31.7 billion in international public adaptation finance in 2024, depending on the accounting method. Another possible starting point is the roughly $40 billion that would follow if the earlier Glasgow doubling goal for 2025 were met.

The two interpretations produce different totals for 2035. The table uses the scenarios in chapter 2 of the UNEP report. The Glasgow row describes what would follow from using the earlier goal as a baseline. It assumes the goal was met.

Why the report uses two figures for need

UNEP puts developing countries’ annual adaptation needs at about $305 billion by 2035 in 2024 prices, largely excluding the private sector’s own additional costs. That central estimate draws on country submissions and modelling, with substantial uncertainty. Assuming 3% annual inflation, the report estimates that the same needs would cost roughly $420 billion in 2035 dollars. Comparing the projected funding with that $420 billion figure produces the 20% to 29% range. UNEP’s estimate and assumptions

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The percentage measures the share that could be covered by international public finance under the tripling scenarios. Domestic budgets and private finance can also fund adaptation. UNEP finds that domestic spending is difficult to track and that even its illustrative domestic-finance estimate would leave more than half of estimated needs unmet when added to tripled international public flows. UNEP’s assessment of domestic flows

When talks open on November 9, readers can judge any new finance announcement by looking for a starting year, a price basis and when the money would arrive. A 2035 annual target says little on its own about how much a city can spend on flood protection over the next few years. United Nations COP31 schedule