The United Nations Environment Programme (UNEP) acknowledged this Wednesday, Oct. 21, that the possibility of keeping global warming below 1.5 degrees Celsius compared with pre-industrial levels has vanished.
The unfortunate news is contained in the 17th edition of the 2026 Emissions Gap Report, which analyzes a “lowest possible” 1.5 degrees Celsius overshoot scenario, in which maximum warming by mid-century is limited to 1.7-1.8 °C and the rise in global temperatures returns to 1.5 °C or below by the year 2100, with a probability of around 50%.
Possibility of keeping global warming below 1.5 degrees Celsius: increase carbon dioxide removal
Previous editions of this report indicated that there was still “an opportunity” if “a herculean effort” was made, Inger Andersen, UNEP executive director, recalled in the Spanish newspaper El Pais. “Now it is clear that this herculean effort was not made. We procrastinated on climate action. And, consequently, we now say that this window has closed.”
The report released this Wednesday warns that, to achieve the goal of a global temperature of 1.5 °C or below by the year 2100, global greenhouse gas (GHG) emissions would have to be reduced by 18% by 2030, 45% by 2035, and 69% by 2040, all compared with 2025 levels.
It would also be necessary, the report continues, to increase carbon dioxide removal throughout the century to limit global warming to 1.5 °C again.
UNEP emphasizes that the full implementation of Nationally Determined Contributions (NDCs) would only reduce emissions by between 5% and 8% by 2030 and between 11% and 15% by 2035, compared with 2025 levels, which would leave the world on track to limit global warming this century to only 2.6 °C.
This would far exceed the historic goal of the Paris Agreement, the global climate change treaty under which countries agreed to keep warming well below 2 °C while striving for a safer limit of 1.5 °C. The UNEP report is clear: Any possibility of keeping the limit at 1.5 °C has been “lost” as a consequence of decades of insufficient climate action.
Deadly floods, brutal heat waves, lives lost
In a statement issued on the occasion of the report’s launch, U.N. Secretary-General Antonio Guterres was simply apocalyptic: “The world can no longer avoid overshooting the 1.5-degree limit, and the consequences are already devastating,” he said.
“Deadly floods, brutal heat waves, devastating wildfires, lives lost, economies paralyzed, inequalities growing ever deeper, and those with the least responsibility are the ones who suffer first and most intensely,” he lamented.
Overall, global greenhouse gas emissions in 2025 remained practically at the same level as the 2024 record, with the difference between the two years too small to distinguish, according to the report.
Carbon emissions coming solely from the burning of coal, oil, and gas (the main driver of climate change) increased slightly in 2025 compared with the previous year.
“Emissions remain at record levels. And national climate plans and current policies fall dangerously short,” Guterres said.
If only current policies were maintained, warming would reach 2.8 °C, according to the report.
New benchmarks
Building on the results of the first Global Stocktake, the report also establishes new sectoral benchmarks consistent with the lowest overshoot scenario (1.5 °C).
In this regard, it details what is needed to expand renewable energy, reduce the energy intensity of primary energy consumption, decrease the share of coal, oil, and gas in total energy supply, and reduce methane emissions beyond 2030.
The report concludes that there are more opportunities than ever to accelerate action. Since the adoption of the Paris Agreement, renewable energy has experienced a boom, total energy supply from coal and oil has grown more slowly than expected, and climate policies have reduced emissions in many places.
Scaling up successful policies to intensify action in line with the objectives of the first Global Stocktake could put the world on track toward the lowest possible 1.5 °C overshoot scenario, it states.