Every public tree that London's boroughs, Transport for London, the Royal Parks and a few other owners have recorded: 1,136,049 trees, along streets, in parks, in school grounds and on council estates. Each is a column of light standing at its own recorded height, coloured by its kind: oaks, planes, cherries and the rest.
It is not every tree in London. Woodland, gardens and most private land are missing; the Greater London Authority estimates the city holds more than eight million trees in all.
The second movement shows the same trees rated by the Greater London Authority for the climate London is expected to have by the 2090s, under a high-emissions scenario (SSP3). Its report scored the 100 commonest kinds, about 95% of the trees, from High to Vulnerable. Only about one tree in 250 is rated High, and one in five Moderate. Six in ten are rated Low and one in ten Vulnerable: together, seven in ten. Trees rated Low or Vulnerable are dimmed to embers. A rating is a projection, not a death sentence: it says how well suited a kind of tree is likely to be, not what will happen to any one tree.
Measured: where each tree stands, its kind, and, where the owner recorded them, its height and age. Below, the Thames, parks, main roads and borough boundaries.
Not measured: the heights are stretched eight times, or the city would look flat. More than a quarter of trees have no recorded height and are drawn at 7 m. Ages are recorded for fewer than half of the trees, so the third movement shows only the old trees someone has written down. The slow wave of brightness that passes across the city, like breathing, is not data.
The records come straight from each owner's inventory, so they vary. Some boroughs list only street trees, others include parks and estates, and some records are several years old. Havering and Croydon could not supply locations, so only Transport for London's roadside trees appear there; Kensington and Chelsea is only partly recorded. These places are labelled on the map; they are not treeless.
Tree data: London Public Realm Trees, Greater London Authority, compiled by GiGL (November 2025). Contains public sector information licensed under the Open Government Licence v3.0. 2090 ratings: GLA, Future Climate Suitability of London's Public Realm Trees. Map data © OpenStreetMap contributors, Open Database Licence, via Geofabrik (16 October 2026). Inspired by the work of Marshmallow Laser Feast; this is an independent piece and not affiliated with them or with the GLA.
The sound is made live in your browser, not recorded: wind that rises and falls like breath, warm chords that darken in 2090, birdsong in the first movement, and a low bell for the oldest trees. Move over the trees and they answer, each kind with its own note. Tap one to send a breath across the city.
Drag to turn; right-drag, Shift and drag, or the arrow keys to move across the map (two fingers on a phone); scroll or pinch to move closer. Hover over a tree to see what it is. The layers button turns the names and the map on and off. The three movements play in turn; tap one to go there, or press 1, 2 or 3.