UNEP report states 1.5°C overshoot occurs within next few years under all emission paths
UNEP document records inevitable short-term exceedance of the Paris 1.5°C limit and outlines a post-peak cooling pathway dependent on unproven carbon removal at scale. Current policy trajectories produce 2.6°C by 2100; optimistic NDC strengthening caps the peak at 1.8°C. Adaptation and CDR timelines now drive near-term planning.
The UN Environment Programme report shifts framing from prevention of 1.5°C exceedance to management of temporary overshoot. It requires rapid fossil fuel phase-out followed by carbon dioxide removal to return temperatures below the threshold by 2100. Current 20-year average stands at 1.4°C.
Data in the report projects every five-year delay in emission cuts adds at least 0.1°C to peak warming. Optimistic scenarios assume strengthened nationally determined contributions that limit overshoot duration to several decades. Current policies produce a hump-shaped trajectory peaking above 2°C before any decline.
Operationally this means governments must prepare infrastructure and adaptation measures for multi-decade periods of elevated extremes while scaling direct air capture and afforestation after 2050. No verified large-scale CDR deployment exists at required gigatonne volumes today.
Rogelj: global temperature returns below 1.5°C before 2100 only if cumulative net-negative emissions exceed 400 GtCO2 after 2050 peak.
Sources (2)
- [1]UNEP Emissions Gap Report 2023(https://www.unep.org/resources/emissions-gap-report-2023)
- [2]IPCC AR6 Working Group I(https://www.ipcc.ch/report/ar6/wg1/)