The lush, dense, quality of rainforests instantly make one think of how beautiful and efficient they are at making fresh air (and thus suck up carbon). As a result of the obvious wonderfulness of rainforests we’ve done a lot of work to try to protect rainforests from destruction. We need to the same in our cities. In London, researchers used LIDAR technology to better understand how much carbon urban trees soak up. Trees in urban centres love to absorb that carbon! The proximity to carbon sources like automobiles make urban trees really effective at air-cleaning so much that they are comparable to rainforests.
Thank your local tree for making your air cleaner!
The UCL team used publicly available airborne lidar data collected by the UK Environment Agency, in conjunction with their ground measurements, to estimate biomass of all the 85,000 trees across Camden. These lidar measurements help to quantify the differences between urban and non-urban trees, allowing scientists to come up with a formula predicting the difference in size-to-mass ratio, and thus measuring the mass of urban trees more accurately.
The findings show that Camden has a median carbon density of around 50 tonnes of carbon per hectare (t/ha), rising to 380 t/ha in spots such as Hampstead Heath and Highgate Cemetery – that’s equivalent to values seen in temperate and tropical rainforests. Camden also has a high carbon density, compared to other cities in Europe and elsewhere. For example, Barcelona and Berlin have mean carbon densities of 7.3 and 11.2 t/ha respectively; major cities in the US have values of 7.7 t/ha and in China the equivalent figure is 21.3 t/ha.