ESG Daily, CLIMATE CHANGE—UN report says warming will overshoot 1.5°C and sets the cuts needed to return by 2100, (Oct 22, 2026)

By Shashi Kant, BALLB, LLM.

The UN Emissions Gap Report 2026 finds that limiting warming to 1.5°C without overshoot is no longer possible.

The United Nations Environment Programme (UNEP) has concluded that the opportunity to limit global warming to 1.5°C above pre-industrial levels with no or limited overshoot has been lost. To return temperatures to 1.5°C by the end of the century, countries must cut greenhouse gas (GHG) emissions 18 percent by 2030, 45 percent by 2035 and 69 percent by 2040, all relative to 2025 levels, according to the Emissions Gap Report 2026, titled “The point of return.” Full implementation of the latest nationally determined contributions (NDCs) under the Paris Agreement would reduce emissions by only 5 to 8 percent by 2030 and 11 to 15 percent by 2035, the report says.

Overshoot pathway. The report measures the emissions gap against what it calls a “lowest possible” 1.5°C overshoot scenario, which assumes stringent mitigation action starting in 2025. That scenario has a 66 percent chance of limiting peak warming to 1.7 to 1.8°C around the middle of the century and around a 50 percent chance of returning warming to 1.5°C by 2100, according to the report. UNEP says the scenario would also require removing and permanently storing roughly 320 gigatons of carbon dioxide this century, and that the ability to do so at that scale is uncertain. Every five years of emissions at current levels raises peak warming by about 0.1°C, the report says. “Overshoot is not surrender,” UN Secretary-General António Guterres said in a message accompanying the report. Guterres said overshoot can still be kept “as small and as short as possible,” and that temperatures can be brought back below 1.5 degrees by the end of the century.

Global emissions. Global GHG emissions reached 58.4 gigatons of carbon dioxide equivalent (GtCO2e) in 2025, a slight decline of 0.1 GtCO2e from 2024, according to the report. UNEP says the high uncertainty range makes it impossible to conclude on the overall direction of emissions in 2025. Carbon dioxide emissions from fossil fuels continued to rise, but lower emissions from land use, land-use change and forestry offset that increase, the report says.

United States. The United States recorded by far the largest emissions increase of any country in 2025, at 133 megatons of carbon dioxide equivalent, according to the report. UNEP attributes the increase to higher electricity demand and a rebound in coal power generation. The report puts per capita emissions in the United States and the Russian Federation at nearly 18 tons of carbon dioxide equivalent, the highest among the six largest emitters, against a world average of 6.4 tons. UNEP says the U.S. withdrawal from the Paris Agreement, together with revised estimates of historical emissions, worsened its warming projections compared with last year. A statement included in the report at the request of the U.S. State Department says the United States does not support the report or endorse its conclusions.

Temperature projections. If current policies continue, there is a 66 percent chance that warming will be limited to 2.8°C by 2100, the report says. Full delivery of all NDCs would limit warming to 2.6°C, according to the report. If all NDCs and net-zero targets are met, warming would be limited to 2.1°C this century, the report says. UNEP finds that new NDCs submitted since last year have a near-zero impact on expected emissions and warming.

National pledges. As of September 1, 2026, 124 parties covering about three-quarters of global GHG emissions had submitted new NDCs, the report says. UNEP calculates an emissions gap of 5 GtCO2e in 2030 and 16 GtCO2e in 2035 between full implementation of current NDCs and the lowest 1.5°C overshoot scenario. Only six Group of 20 (G20) members are likely to meet their unconditional 2030 targets under current policies, according to the report. The report names them as China, India, Indonesia, the Russian Federation, South Africa and Türkiye.

Policy evidence. In 2025, renewable power production exceeded coal power in the global electricity mix for the first time, according to the report. UNEP says more than 220 policy evaluations provide causal evidence that climate policies reduce emissions across a wide range of sectors and countries.

Next steps. In the report’s foreword, UNEP Executive Director Inger Andersen says nations must find ways to increase action at the United Nations Climate Change Conference (COP 31) in November, during the second global stocktake and at the second International Conference on the Just Transition Away from Fossil Fuels in July 2027. UNEP has also issued a press release and related materials with the report.

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