The path to 1.5°C

Limiting warming to 1.5°C is no longer possible without overshoot. The question now is how short and low that overshoot can be kept. The path to 1.5°C draws on the new generation of climate scenarios published in 2026, which will inform the IPCC’s Seventh Assessment Report, to set out what the lowest-overshoot pathways demand of the global energy system. The report first looks back. Over the past decade, clean energy capacity grew at record rates, but rising energy demand outpaced efficiency gains and renewables, and coal and gas filled the gap. Emissions from 2020 to 2025 ran nearly 50 GtCO₂eq above the pathways that could have avoided overshoot, with power generation the largest contributor. It then looks ahead to 2035. The lowest-overshoot pathways peak at around 1.7°C mid-century and return to 1.5°C by 2100, but only with a step change across the energy system: doubling the rate of efficiency improvement, renewable generation growing by nearly 12% a year, and coal and gas power in steep decline. Existing global goals on renewables, efficiency and electrification align with these pathways. Delivering them is the challenge, and every year of delay raises peak warming.