New Delhi: The planet is set to overshoot the critical 1.5 degree Celsius threshold, the lower limit of the Paris Agreement, in the next few years, according to a new United Nations Environment Programme (UNEP) report released today.
Even an optimistic scenario based on current country pledges, including full implementation of all national climate plans and meeting net-zero emissions targets, puts the expected peak temperature rise at 1.8 degree Celsius over pre-industrial levels.
This would mean the planet faces severe impacts of climate change, including significant changes to ice sheets, sea ice, glaciers, permafrost and snow.
For example, glaciers could lose more than a quarter of their mass by 2100, potentially raising sea levels by 9 to 12.5 cm and permanently altering water availability in many places. The report sounded the alarm days after the August 26 flash floods in Nepal and Tibet following a glacier collapse that led to seismic signals and devastating flash floods downstream, killing over 1,000 people.
“There are no good outcomes if we remain above 1.5 degree Celsius. Across the globe, extreme heatwaves are already proving that climate impacts will strike faster, hit harder, and last longer – costing more lives and causing deeper disruption, now is the time we must double down on climate action. We can – and must – get on the right path. By cutting greenhouse gas emissions, strengthening resilience and adaptation, and ensuring exceedance of 1.5 degree Celsius is as small and short as possible,” UNEP Executive Director Inger Andersen said.
Other risks and impacts include faster sea-level rise, a higher likelihood of ecosystem collapse, such as coral reefs, and more extreme heat and wildfires. There is also a higher risk of irreversible tipping points involving global systems such as the West Antarctic and Greenland ice sheets, the Atlantic Meridional Overturning Circulation (AMOC) and the Amazon rainforest, which would reshape the world forever.
While there are uncertainties around the timing and strength of these impacts and tipping points, UNEP has stressed that it is still possible to bring temperatures down and achieve global goals under the Paris Agreement.
The report, ‘Limiting Overshoot’, identifies an “overshoot, peak, and decline” pathway as the best remaining option to minimise the magnitude and duration of the overshoot and try to return to below 1.5 degree Celsius as soon as possible.
“This summer’s scorching heat, raging wildfires and deadly floods are a warning of what lies ahead. We must make the overshoot above 1.5 degrees as small and short as possible. That demands an overshoot of ambition,” UN Secretary-General Antonio Guterres said in a statement.
This pathway would minimise peak temperature rise through immediate and sustained cuts to greenhouse gas emissions, including methane, on the road to net-zero. It would then bring down temperatures through long-term net-negative emissions, with carefully governed Carbon Dioxide Removal (CDR) – the process of removing carbon from the air and storing it through afforestation or other means – as an essential part of the mix.
National climate pledges are nowhere near sufficient, the report said. Analysis of mitigation pledges submitted as part of countries’ nationally determined contributions (NDCs) under the Paris Agreement revealed a substantial emission gap.
While full implementation of the most recent, third-round NDCs as submitted by September 2025 may show a slight decline in greenhouse gas (GHG) emissions from their record 2024 levels, it will still leave a substantial emissions gap.
A further challenge is the persistent implementation gap between pledged emission reductions and policies currently in place to deliver them, UNEP said. Under currently implemented or planned policies, global emissions are projected not to decline but to remain broadly stable through 2030.
In both cases, the outlook to 2030 remains markedly above levels consistent with pathways that limit warming below 2 degree Celsius, let alone return it to 1.5 degree Celsius by 2100 after a limited overshoot, the report said. The existence of both ambition and implementation gaps has been consistently highlighted in scientific assessments over many years by UNEP.
