The world has lost the opportunity to avoid exceeding 1.5°C of warming by more than 0.1°C but urgent cuts in greenhouse gas emissions could limit how far temperatures rise and bring global warming back to that level by the end of the century, a new United Nations report warns.
Decades of insufficient climate action have made it impossible to limit warming to 1.5°C with no or only a very small overshoot, the United Nations Environment Programme’s Emissions Gap Report 2026: The Point of Return finds. Overshoot means temporarily exceeding the 1.5°C limit.
To achieve the lowest-overshoot pathway assessed in the report, global greenhouse gas emissions must fall by 18% by 2030, 45% by 2035 and 69% by 2040, compared with 2025 levels.
But even if countries fully implement their latest national climate pledges, emissions would decline by only 5% to 8% by 2030 and 11% to 15% by 2035.
Even under the report’s lowest-overshoot scenario, global temperatures would rise to about 1.7°C to 1.8°C above pre-industrial levels around the middle of the century before falling again. There is a 66% chance of keeping peak warming within that range and about a 50% chance of bringing temperatures back to 1.5°C or below by 2100.
If current policies continue, warming could reach 2.8°C by 2100 and rise further thereafter. Fully implementing countries’ climate pledges, followed by similar efforts, would limit warming to 2.6°C.
Even if countries met all their climate pledges and additional net-zero targets, warming would reach about 2.1°C.
“The opportunity to bridge the 1.5°C emissions gap with ‘no or limited’ overshoot has been lost,” the report said. “Decades of insufficient mitigation action means that larger exceedance of 1.5°C above pre-industrial levels based on multidecadal averages is now imminent and unavoidable.”
The report warns that every additional fraction of a degree of warming, and every year spent above 1.5°C, increases the risk of irreversible damage to ice sheets, frozen ground, ocean circulation and coral reefs, as well as devastating impacts on people.
The task now, therefore, is not only to ensure that global warming stays well below 2°C, but to minimise the duration and magnitude of overshoot and establish a credible return path to 1.5°C by the end of the century.
Global greenhouse gas emissions reached an estimated 58.4 billion tonnes of carbon dioxide equivalent in 2025, about 0.1 billion tonnes less than in 2024. But the estimate is too uncertain to tell whether emissions are falling, levelling off or reaching a peak.
Emissions from burning fossil fuels, nitrous oxide and fluorinated gases continued to rise, while methane emissions remained almost unchanged. Lower emissions from land use, partly because wildfires released less greenhouse gas than in 2024, offset the increases.
The gap between countries’ climate pledges and the emissions cuts expected under current policies appears to have narrowed. But the report finds that this does not reflect stronger climate action.
Instead, it is largely because the US’s national pledge was removed from global calculations after its withdrawal from the Paris Agreement, with projections based on its current policies used instead.
Without this change, there has been little overall progress in bringing government policies into line with the pledges.
The consequences of further delay are significant. Every five years of CO₂ emissions at current levels amounts to about 200 billion tonnes released, raising peak warming by around 0.1°C, the report said.
Bringing global warming back to 1.5°C would also require removing about 320 billion tonnes of carbon dioxide from the atmosphere over the course of this century and storing it permanently. That is equivalent to about eight years of global carbon dioxide emissions at 2024 levels.
The report warns that removing and storing so much carbon would be technically and economically challenging and it is uncertain whether it can be achieved at that scale.
All G20 members except Argentina, Saudi Arabia and the US have submitted new national climate plans with emissions-reduction targets for 2035. Mexico is the only G20 country to have strengthened its 2030 target in its latest plan.
Under current policies, only six G20 members — China, India, Indonesia, Russia, South Africa and Türkiye — will probably meet their unconditional 2030 targets, the report finds.
But meeting India’s target for reducing emissions relative to the size of its economy does not necessarily mean its total emissions will fall. Its overall greenhouse gas emissions are projected to rise.
Countries are also falling behind on wider climate commitments, including tripling renewable energy capacity, doubling the rate of energy-efficiency improvements by 2030, moving away from fossil fuels and halting and reversing deforestation.
There has been progress on renewable energy. Since the Paris Agreement was adopted in 2015, solar and wind power have expanded much faster than expected. Renewable electricity capacity grew three times faster than projected in the report’s 2015 scenarios, while solar power capacity grew seven times faster than anticipated.
But progress elsewhere remains too slow. The world continues to use more coal, oil and gas, although growth has slowed and efforts to stop deforestation remain far off track.
To keep warming as close as possible to 1.5°C, global renewable electricity capacity would need to reach at least three times its 2025 level by 2035 and 4.5 times that level by 2040.
Coal-fired electricity generation would need to fall by at least 75% by 2035, with coal power effectively phased out worldwide by 2040.
The report also finds evidence that climate policies can cut emissions. An analysis of more than 220 policy evaluations found that electricity-sector policies reduced emissions by an average of 9% compared with what would have happened without those policies.
Carbon taxes and emissions-trading schemes were associated with emissions reductions of 5% to 13% across sectors, compared with what would have happened without those policies. The results varied widely, depending on how the policies were designed and where they were applied.
Unep executive director Inger Andersen said there were numerous examples of emissions being cut quickly, but governments needed to introduce policies that delivered fast, deep and sustained reductions.