Our cities can still choose their climate future

The climate debate is conducted at the wrong altitude. It lives in the thin air of summits and national targets, of pledges measured to the decimal and quietly revised at the next election. Watch that theatre long enough and one conclusion becomes hard to avoid: almost nothing settled in those rooms changes a single tonne of anyone's emissions. The things that do — how you reach work, how warm your flat is in February, whether your street bakes like a pan in July — are not set by a head of state. They are set by a city. And across borders, cities have stopped waiting.

The arithmetic favours them. Cities hold most of the world's people, most of its energy demand and nearly all of the levers a transition actually turns on. A capital can announce a target; it cannot, by decree, insulate ten thousand draughty blocks, lay a bus lane, plant a street of planes or rewrite a zoning code so that a school and a clinic sit within walking distance of a home. Mayors can, and do. While heads of state were softening the wording of a deal gavelled through at four in the morning, second cities from Lyon to Gaziantep to Leeds were already at work.

The dull list that delivers

The municipal toolkit is unglamorous, and that is its strength. Transit frequent enough to leave the car at home. Deep retrofits that halve a building's heating demand before a single heat pump is fitted. Density that puts a grocer, a clinic and a school within a fifteen-minute walk. Heat-action plans — cool roofs, shaded corridors, pools kept open — that are no longer a comfort but, in a warming summer, a question of who survives the week. None of it fills a communiqué. All of it works, on a timescale that national politics, hostage to the next ballot, cannot hold to.

The instructive part is who leads. Not the marquee capitals but the second cities — regional hubs of two or three hundred thousand, nimble enough to redirect a budget inside one council term and small enough that a mayor can stand in a rebuilt square and point at the result. These places are not asking permission. They are swapping playbooks across borders, lifting what worked in Malmö into Bilbao and what worked in Bologna into Bristol, assembling a quiet international of competence that runs beneath the noise of the nation-state.

None of this is a reason for triumphalism. Cities cannot price carbon, cannot regulate a national grid, cannot summon the capital a full retrofit programme demands; they run perpetually short of the money and the legal authority their ambition has already outgrown. The municipal route is not a replacement for national and treaty-level action — it is the layer where that action becomes concrete or dissolves. A grand pledge that no city is equipped to execute is a press release with a longer shelf life.

Hand them the levers

Which is why the most useful move available to national governments is humbler than another headline target: give cities the money and the powers to do what they have already proven they can. Let them keep a share of the revenue from the buildings they decarbonise. Grant borrowing powers indexed to the emissions they actually cut. Stop making a mayor petition a ministry to turn a car park into a wood. The competence is not in doubt. The constraints are the problem.

Read across enough retrofitted streets, in enough ordinary cities, and the fashionable despair that passes for climate realism starts to look like a failure of address. The future is not settled once, in a distant hall, by exhausted negotiators. It is settled a thousand times over — in council chambers, planning offices and on the streets where most of humanity now lives. Those decisions remain open. The cities making them are not waiting to be rescued; they are, without applause, getting on with rescuing themselves. The rest of us should hand them the tools and step out of the way.