Clean energy is expanding far faster than expected, yet the world remains on course for 2.8°C of global warming by the end of the century under current policies.

The latest UN Emissions Gap Report highlights a troubling paradox: while solar and wind power are booming, fossil-fuel emissions remain stubbornly high.

The United States’ withdrawal from the Paris Climate Agreement has further worsened the outlook. American coal-fired electricity generation surged in 2025, just as transport, industry, and heating increasingly depend on cleaner electricity.

Even if countries fulfill their climate commitments, global warming is projected to reach 2.6°C by 2100, compared with 2.3–2.5°C in last year’s assessment.

According to the UN Environment Program (UNEP), limiting the damage requires global greenhouse gas emissions to fall by 18% by 2030 and 45% by 2035, compared with 2025 levels. UNEP now considers temporarily exceeding the Paris Agreement’s 1.5°C target unavoidable, although returning to that level by 2100 remains technically possible.

“Every additional fraction of a degree and additional year of warming above 1.5°C increases climate impacts and risks […], so we must minimize peak warming and return to 1.5°C by the end of the century,” said UNEP Executive Director Inger Andersen.

Urgent action needed

The report finds that if current policies continue, warming could reach 2.8°C this century, and rise further thereafter. If all Nationally Determined Contributions (NDCs) are delivered and similar efforts continue, warming will be limited to ‘only’ 2.6°C.

But even in the most optimistic scenario, where all NDCs plus additional net-zero targets are achieved, global warming would only be limited to 2.1°C in this century. Without urgent action, keeping peak warming below 1.7 to 1.8°C will quickly become impossible.

‘More opportunities’

Yet the report is not entirely negative. UNEP observes that there are “more opportunities than ever” to accelerate sustainable development. For example, the organization points out that the share of renewable energy is growing much faster than was thought possible a decade ago. 

Overall renewable-energy capacity has expanded approximately three times faster than earlier projections anticipated. Solar power capacity has grown seven times faster than expected when the Paris Agreement was adopted in 2015.

Paris Climate Agreement

Returning to or below 1.5°C is possible, especially since growing evidence shows that climate policies worldwide can and have reduced emissions. The report links the introduction or strengthening of climate-related policies to dozens of structural shifts in developed and developing countries, resulting in significant emissions reductions.

Yet the successes remain concentrated in specific sectors, countries, and periods. Reaching a 1.5°C overshoot pathway requires replicating, extending, and sustaining these successes.

The good news is that since the Paris Agreement, global renewable electricity capacity has grown three times faster than anticipated, with solar PV build-out increasing sevenfold.

Continuing these trends, supported by additional policies, would put the world on track to triple renewable energy capacity by 2030 and raise the share of wind and solar in electricity generation to levels consistent with the lowest possible 1.5°C overshoot scenario.

Conclusion

Clean-energy technologies are advancing much faster than expected, but continued fossil-fuel dependence and shifting political commitments are constraining their climate benefits. Climate outcomes depend not only on technological progress, but on how rapidly governments, businesses and consumers replace existing fossil-fuel systems.