UCL Department of Geography


UK urban forest may store as much carbon as tropical rainforests

2 July 2018

UCL Geography team sheds new light on carbon storage and climate change mitigation by London's trees

UK urban forest may store as much carbon as tropical rainforests

A study, published in Carbon Balance and Management, uses publicly-available airborne and ground-based LiDAR (Light Detection and Ranging) data, collected by the UK Environment Agency, to generate a map of the carbon stored in an estimated 85,000 trees across the London Borough of Camden.

It was found that areas such as Hampstead Heath store up to 178 tonnes of carbon per hectare, compared to the median value for tropical rainforests of 190 tonnes.

Dr Phil Wilkes, a Post-Doctoral Research Associate and lead author of the study, explains:

“Urban trees are a vital resource for our cities that people walk past every day. We were able to map the size and shape of every tree in Camden, from forests in large parks to individual trees in back gardens. This not only allows us to measure how much carbon is stored in these trees but also assess other important services they provide such as habitat for birds and insects."

Ground-based LiDAR is a technique pioneered by the UCL team to measure carbon in tropical rainforests, now used for the first time in Camden, UCL’s local borough. Previous estimates of carbon storage have relied on measurements from trees outside cities, which may be quite different.

Urban trees provide many ecosystem services essential for making cities livable, including providing shade, flood mitigation, filtering air pollution, and habitat for birds, mammals and other plants, as well as wider recreational and aesthetic benefits.

Treeconomics estimates that the services provided by urban trees in Greater London are worth £133m per annum. The carbon storage capacity of urban trees alone is valued to be worth £4.8m per annum in Greater London, or £17.80 per tree.

Dr Mat Disney, co-author and leader of the UCL Geography LiDAR research group.

"An important outcome of our work was to highlight the value of urban trees, in their various and very different settings. The approach has been really successful so far, so we're extending it across London, to other cities in the UK and internationally,”

Sir Harry Studholme, Chair of the Forestry Commission adds,

“The trees in our cities are important. They matter because they are close to people and are a key component of our urban environment, providing beauty, shade and homes for myriad species as well as absorbing carbon and pollutants. The work being carried out at UCL is adding colour and detail to this understanding,”

The work was funded by the Natural Environment Research Council, in part through the National Centre for Earth Observation (NCEO). The team are also grateful to David Houghton, Interim Tree Manager for Camden Council and Highgate Cemetery for access to data and sites.