UNEP: Global emissions must fall 45% by 2035 to limit 1.5°C overshoot

The report’s “lowest possible” overshoot scenario limits peak warming to 1.7-1.8°C around mid-century before temperatures return to or below 1.5°C by 2100, with a roughly 50% probability. Achieving this pathway would require emissions to fall 69% by 2040 and substantial carbon dioxide removal throughout the century.

Warming projections remain high:

Under current policies, global temperatures could rise by 2.8°C this century. Full implementation of national climate commitments would limit warming to 2.6°C, while achieving those commitments alongside additional net-zero targets would still result in 2.1°C of warming.

The report attributes the deterioration in projections from last year partly to the US withdrawal from the Paris Agreement and revised estimates of historical emissions. It warns that every five years of CO2 emissions at current levels adds around 0.1°C to peak warming.

The lowest-overshoot pathway would also require removing and permanently storing around 320 gigatons of CO2 this century, equivalent to roughly eight years of global CO2 emissions at 2024 levels. Achieving this remains uncertain due to technological and socioeconomic challenges.

Climate action delivers results:

UNEP highlights opportunities to accelerate emissions cuts, citing the rapid expansion of renewable energy, slower-than-projected growth in coal and oil supply, and emissions reductions achieved through climate policies since the adoption of the Paris Agreement.

“Overshoot is not surrender. We can still keep it as small and as short as possible – and bring temperatures back below 1.5 degrees by the end of the century,” UN Secretary-General António Guterres said, calling for emissions cuts of 18% by 2030 and 45% by 2035 from 2025 levels.

An assessment of more than 220 policy evaluations found that electricity-sector policies cut emissions by an average of 9%, while economic instruments, including carbon taxes and emissions trading schemes, achieved reductions of 5%-13% across sectors. However, these gains remain concentrated in specific countries, sectors and periods, underscoring the need to expand and sustain successful policies.

UNEP Executive Director Inger Andersen warned that every additional fraction of a degree and year of warming above 1.5°C increases climate risks, including floods, heatwaves and wildfires.

“We have a wealth of success stories showing that emissions can be cut quickly,” Andersen said, urging governments to implement policies that deliver “fast, deep and sustained emissions reductions” to support a more stable climate, economies and societies.

Renewable energy, fossil fuel targets:

The report calls for countries to build on the first Global Stocktake by extending climate targets to 2035 and 2040.

By 2035, global renewable electricity capacity would need to reach at least three times its 2025 level, while primary energy intensity of GDP would need to fall by at least 30%. By 2040, renewable electricity capacity would need to reach at least 4.5 times its 2025 level, with energy intensity reduced by at least 40%.

Since the Paris Agreement, global renewable electricity capacity has grown three times faster than anticipated, while solar photovoltaic deployment has expanded seven times faster. Sustaining this progress alongside stronger policies could help achieve the 2030 renewable energy target.

The pathway also requires reducing the shares of coal, oil and gas in total energy supply by at least 55%, 15% and 5%, respectively, by 2035 from 2025 levels. By 2040, the reductions would need to reach 75%, 30% and 35%.

Coal-fired electricity generation must fall by at least 75% by 2035 and be effectively phased out globally by 2040. Methane emissions must decline by at least 25% by 2035 and 40% by 2040, relative to 2025 levels.