As we breach 1.5 °C, we must replace temperature limits with clean-energy targets

On 28 October 2025, United Nations secretary-general António Guterres acknowledged that the totemic goal of the Paris climate agreement is going to be missed: “The truth is that we have failed to avoid an overshooting above 1.5 °C in the next few years”1.

Approaching 1.5 °C: how will we know we’ve reached this crucial warming mark?

Guterres was merely stating the obvious. In 2024, Earth’s global mean surface temperature averaged 1.55 °C above pre-industrial levels2, and the average for 2023–25 is 1.48 °C, perilously close to the limit. Keeping to the Paris target now looks impossible by any realistic measure. Yet this moment should not invite despair. Instead, it demands an urgent reframing of how climate progress is measured and mobilized.

The world today looks very different from that in 2015 when the Paris goal was framed. Although emissions are still rising and global actions on climate change are slow, a lot of progress has been made. Clean energy is expanding rapidly and decarbonization, not fossil fuels, is the new ‘business as usual’. In the first three quarters of 2025, growth in clean electricity generation outpaced that in energy demand for the first time, implying that fossil fuels are being displaced (see go.nature.com/3jvqzcb).

We argue that the main focus of climate action in 2026 and beyond should be on accelerating the clean-energy revolution. And the rate at which clean energy displaces fossil fuels in the global economy should become the key measure of climate progress. Here we describe how such progress can be tracked and incentivized using a metric we call the clean-energy shift. Unlike chasing intangible temperature targets, cleaning up the energy sector is a more-focused battle that the world can win.