IS THE 1.5°C TARGET STILL VALID?
We keep hearing it more and more often: “we’ve already passed 1.5°C”.It is one of those statements that seems to shut down the conversation before it even begins.
In 2024, the global average temperature reached an anomaly greater than 1.5°C: this is historic data, but it does not mean the Paris target is “dead”.
Understanding why requires a bit more precision.
It’s not about a single year
The Paris Agreement is based on multi-year rolling averages, not on the record of a single year. The climate system fluctuates: even in the best-case scenarios, the IPCC foresees brief temporary overshoots. What matters is the trajectory.
Today, the trajectory is not good, but we are not yet in a situation where the multi-year average has stably exceeded 1.5°C.
The uncomfortable point: today’s trajectory leads to more than 2.5°C
The 2025 UNEP Emissions Gap Report leaves little room for optimism: even including the most recent updates to national commitments, we are heading towards an increase of 2.5–2.8°C.
Translated: to remain at 1.5°C, we would need emissions cuts of a scale never seen in human history.
Is it difficult? Very. And this is where the confusion begins: in the rooms of COP30 we heard this distance from the ideal trajectory being used to declare the target “dead”.
But that’s not how a climate threshold works.
So does the 1.5°C objective still make sense?
Yes, but not because we have any guarantee of meeting it.
It matters because it is a scientific and political benchmark that marks the difference between moderate damage and much more severe damage.
Abandoning it would mean two things: relieving pressure on governments and passively accepting impacts we can, must, avoid.
And it would be a major gift to the so-called climate delayers: people, groups or governments working to slow down the response to the climate crisis.
The most important point: every tenth of a degree counts
We often talk about 1.5°C as if it were a switch, either in or out. It isn’t, and science has always been absolutely clear on this: every tenth of a degree of avoided warming measurably reduces impacts on health and safety, losses and damages, infrastructure, ecosystems.
This is not moral philosophy. It is thermodynamics applied to people’s lives.
And this does not change even if we were to exceed the 1.5°C threshold permanently.
It holds at 1.6°C and 1.7°C, at 1.9°C and even at 2.1°C: the room for action never completely disappears.
Reaching the 1.5°C target is now a race against time with very low chances of success. But this is not a reason to stop running it.
The limit remains valid because it describes what happens in the real world, not what suits the negotiations. And because every tenth of a degree avoided can save millions of lives.
Article by Serena Giacomin, Scientific Director of Italian Climate Network
Cover image: UNFCCC