Chapter 01 · Climate & transitionClimate & Greenhouse Gas Emissions
Adaptation gap
Definition
The shortfall between estimated adaptation needs and current adaptation action, most prominently measured in finance. UNEP's Adaptation Gap Report 2025 puts developing countries' adaptation costs at USD 310–365 billion per year to 2035, against international public adaptation finance flows of USD 26 billion in 2023 — a finance gap of USD 284–339 billion a year.
References
Costs of USD 310bn (modelled) to USD 365bn (NDC/NAP-extrapolated) per year by 2035; USD 26bn flows in 2023; 12–14× gap; Glasgow goal off track.
USD 284–339bn annual finance gap; NCQG insufficiency; Paris Article 9 balance commitment.
Overview
What it means
The gap has three dimensions: finance (needs estimated at 12–14 times current flows), planning (most countries now have at least one national adaptation policy, strategy or plan) and implementation (progress, but limited; over 1,600 implemented adaptation actions were reported in the 2025 assessment). The Glasgow Climate Pact goal of doubling 2019 adaptation finance by 2025 is off track under current trends.
How it is used
UNEP has published the Adaptation Gap Report series since 2014 to inform UNFCCC negotiations ahead of each COP. Governments, civil society and media cite its figures in debates over the new collective quantified goal on climate finance (NCQG) and the adequacy of adaptation support.
Why it matters
The adaptation gap quantifies how far climate-vulnerable countries are from the resources their stated plans require. Its persistence — and the growing share of non-concessional, debt-based instruments within adaptation finance — raises equity concerns, since the countries most exposed to impacts contributed least to causing them.