Paris Gap

If every country meets its current Paris Agreement pledge (NDC), global warming still reaches roughly 2.3-2.5 degrees Celsius by 2100. The Paris Agreement's goal is 1.5-2.0C. The gap between what countries have promised and what is needed is the "Paris gap," and it has not narrowed meaningfully since 2015.

The UNEP Emissions Gap Report tracks this annually. As of 2025, current policies (not pledges, actual implementation) put the world on track for roughly 2.8C. Full implementation of all NDCs (including conditional pledges contingent on international finance) would limit warming to about 2.3-2.5C. The 1.5C pathway requires cutting global emissions roughly 43% below 2019 levels by 2030. Actual emissions in 2023 hit a new record high.

The arithmetic. Global CO2 emissions in 2023: ~37 Gt. The 1.5C pathway requires roughly 21 Gt by 2030. Current NDCs imply roughly 30 Gt by 2030. The gap: roughly 9 Gt CO2 per year, equivalent to the combined emissions of the US and EU.

Why hasn't the ratchet mechanism closed the gap?

Because NDC updates have been incremental. The Paris Agreement requires countries to submit updated (and theoretically more ambitious) NDCs every five years. In practice, most updates have added modest improvements rather than the step changes needed. Countries face no penalty for weak updates. The voluntary structure that made Paris politically achievable also makes it structurally unable to close its own gap without a mechanism the agreement does not contain: enforcement.

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