UN Says the World Will Overshoot 1.5°C, but a Return Path Remains

Keypoints:

• The United Nations Environment Programme (UNEP) published its 17th Emissions Gap Report on 21 October, titled "The Point of Return"
• It finds that exceeding 1.5°C is now unavoidable
• Current policies point to about 2.8°C of warming by 2100
• Global emissions in 2025 were about 58.4 billion tonnes of CO2 equivalent, slightly below 2024
• Emissions must fall about 45% below 2025 levels by 2035 to limit the overshoot

The UNEP released its annual Emissions Gap Report on 21 October. The title, "The Point of Return," signals the main shift. Decades of insufficient action have made temporary overshoot of the 1.5°C limit unavoidable. The task now, the report says, is to keep warming well below 2°C and to limit how long and how far the world stays above 1.5°C. UN Secretary-General António Guterres said the overshoot is not surrender.

The numbers set the scale. Under current policies, the world is heading for about 2.8°C by 2100. Global greenhouse gas emissions totaled about 58.4 billion tonnes of CO2 equivalent in 2025. That is slightly below 2024. The dip is not a sign of relief, because emissions from fossil fuels kept rising. The decline came mainly from fewer wildfires than in 2024. The Group of 20 (G20) countries account for 76% of global emissions, and their emissions excluding land use rose 0.7%.

Climate scientist Lauri Myllyvirta pointed out another view. Even if 2026 does not mark the peak, the report projects a 5-8% drop by 2030 relative to 2025. That is far below the pace needed.

The report sets out a lowest-possible overshoot scenario. Peak warming near mid-century would be limited to 1.7-1.8°C. Temperatures would then return to 1.5°C or below by 2100, with about a 50% chance. That requires cutting emissions about 45% below 2025 levels by 2035, or about 5.7% a year between 2025 and 2035. Every five years of delay at today's emissions adds about 0.1°C to peak warming.

There is some evidence of progress. By 1 September 2026, 124 countries covering about 76% of emissions had submitted new national climate plans. The year before, 57 countries covering 63% had done so. The report also cites more than 220 policy evaluations. Electricity-sector policies cut emissions by 9% on average, and carbon pricing cut emissions by 5-13% across sectors.

The timing matters, with the COP31 climate summit due in November. The report's central lesson is that every year of delay raises the cost of the return.