1.5C warming limit now impossible to meet without overshoot, UNEP warns

Keeping global warming to 1.5 degrees Celsius without a temporary breach is no longer achievable, the UN Environment Programme said in its annual Emissions Gap Report, citing decades of insufficient climate action.

Global greenhouse gas emissions totalled 58.4 billion tonnes of CO2 equivalent in 2025 — roughly 0.16 GtCO2e below 2024 levels, though UNEP cautioned that the figures are provisional and that "it is not possible to conclude on the overall direction of emissions in 2025." The growth rate has slowed: from an average of 1.7% per year over 1990–2015 to 0.8% per year since 2016, the report said.

Exceeding 1.5C is now "imminent and unavoidable", UNEP said in the report, titled "The point of return". Even the lowest possible overshoot scenario would see temperatures peak at around 1.7–1.8C in the middle of the century before declining — a trajectory UNEP described as still consistent with the long-term goals of the Paris Agreement, but only if global emissions are cut 18% by 2030 and 45% by 2035, alongside a ramp-up in carbon dioxide removal.

Current national climate pledges, even if fully implemented, would reduce emissions by only 5–8% by 2030 and 11–15% by 2035 relative to 2025 levels, the report found. Those pledges fall well short of what is needed, UNEP said, noting that compared with the cuts required to minimise overshoot, the gap remains large.

Compared to 2024, emissions from fossil fuels increased slightly, by between 0.4–1.1%. Emissions of both nitrous oxide and fluorinated gases increased by even higher rates, though UNEP noted their contribution to the overall trend is "relatively less significant" given their small share of total greenhouse gas emissions. Methane emissions remained steady, while a reduction in CO2 emissions from land use, land-use change and forestry slightly overcompensated for the rise in fossil-fuel CO2 and other gases.

Despite the bleak headline, UNEP said "ample opportunity" exists to accelerate action and that countries can still limit the peak temperature, shorten the duration of overshoot and keep Paris Agreement goals within reach.