"Protecting our urban trees will help reduce the impacts of climate change,"
explains Macarena Cárdenas
Our neighbourhood trees are as important as rainforests in their capacity to absorb carbon dioxide (CO₂), according to a recent study.
Research on trees in Camden, London, revealed that the carbon mass contained amongst the population of trees can be compared to the density of carbon stored in rainforests. Given that 55% of the world’s population lives in cities, this highlights that urban trees are critical in absorbing CO₂, one of the major contributors to climate change.
Macarena Cárdenas is a research manager at Earthwatch Europe. Watch our video for more from her on climate action.
The study, performed by University College London, used a cutting-edge laser scanning technique that creates a 3D image of each tree, to measure the biomass of urban trees much more accurately.
Using the results from the data collected in Camden, the team calculated the mass and estimated the carbon content of around 85,000 urban trees.
The findings show that Camden has a median carbon density of around 50 tonnes of carbon per hectare, rising to 380 tonnes per hectare in some spots. This carbon density is equivalent to the amount of carbon measured in trees in temperate and tropical rainforests.
We're researching their other valuable services...
In addition to trees functioning as carbon stores, there is much more to discover about the ecosystem services they provide. For example, the benefits to the environment provided by London’s trees were recently estimated to be valued at £130m a year.
Our research on urban trees aims to find out more about their valuable services. In partnership with HSBC and key international academic institutions, we are investigating the role of green and blue spaces in enabling cities to mitigate against climate change and the negative impacts of urbanisation.
For example, our joint Sustainable Cities Europe research project is looking at the potential of urban trees in helping to mitigate against the effects of flooding, and of the ‘urban heat island effect’ – which is the significant excess of heat in urban areas compared to the surrounding land, caused by human activity.
We are also identifying the best land management practices to facilitate this role.
Awareness of the valuable services our urban trees provide will hopefully help prevent detrimental land management decisions reoccurring, such as the felling of street trees in Sheffield.
The urban forest not only provides key ecosystem services for mitigating the impacts of climate change and urbanisation – helping enhance well-being and human health – but also plays a key role in building more resilient and sustainable cities.