Climate: a clock inside the clock

Climate joined the Doomsday Clock in 2007, sixty years after its creation. Every Bulletin statement since has devoted a section to it. But it works differently from nuclear weapons: no fatal instant, a slow degradation that makes every other risk worse. That is why 'end of the world' is the wrong phrase — and why the danger is real.

Where do we stand?

Global average temperature exceeded +1.5 °C above pre-industrial levels across 2024 — the first time for a full calendar year — with 2025 close behind (Copernicus, WMO). Global CO₂ emissions have not yet started to fall: ~37 billion tonnes in 2024, a record. At current rates the carbon budget consistent with 1.5 °C will be exhausted before 2030.

What is the Climate Clock?

The Climate Clock (climateclock.world), unveiled in 2020 on a Manhattan façade, is a genuine countdown: it shows the time left before that carbon budget is used up, as calculated by the Mercator Research Institute (MCC Berlin). It also shows a 'lifeline': the share of renewables in the global energy mix. It complements the Doomsday Clock: one counts tonnes, the other expresses a judgement.

Tipping points

This is the heart of scientific concern. Some parts of the climate system can flip abruptly and irreversibly once a threshold is crossed: the Greenland ice sheet (+7 m of sea level eventually), West Antarctica, permafrost (releasing methane), coral reefs (already under way), and the Atlantic ocean circulation (AMOC), whose slowdown would upend Europe's climate. The Global Tipping Points Report (2023) puts five of these thresholds within reach at +1.5 °C. That is what the 'tipping point' card in the simulator represents.

Why it is not the end of the world — and why it is serious anyway

No IPCC scenario, even the worst, leads to human extinction. Warming of +3 °C or +4 °C would, however, make some regions uninhabitable for part of the year, slash crop yields in the tropics, displace hundreds of millions of people and multiply conflicts over water and land. Climate is not the bomb: it is the multiplier that makes the bomb more likely. In the simulator, switch on a tipping point and then a regional war: that is the chain.

What has worked

The ozone hole: the Montreal Protocol (1987) banned CFCs and the layer is recovering — the only environmental treaty ratified by every country on Earth. Solar power: its cost fell 90% in a decade and it is now the cheapest electricity in history in most regions. EU emissions are down 37% since 1990 while the economy grew. None of this was a given in 2007.

And at my scale?

Individual choices (travel, heating, food, flying) matter, but their main effect is social: they normalise a behaviour. The higher-leverage actions are collective ones: your savings (funds labelled Article 9 in the EU, or simply leaving the banks most exposed to coal), your voice in your company or town (mobility plans, retrofits, procurement), and your vote — climate policy is decided at municipal level as much as national. See Act.