Trees could more than halve air pollution in urban hotspots, MPs told

Last week the Environment, Food and Rural Affairs Committee held the first evidence session of its inquiry into urban green spaces: ‘Green spaces for urban places: How they improve life for people in built-up areas’

The session explored the environmental challenges faced by urban areas, the impacts of these challenges and the role of green spaces in combatting them.

Public Health England have estimated that the NHS could save £2.1 billion in treatment costs each year if everyone in the country had equal access to good quality green spaces where they could exercise. As such, the cross-party Committee set out to investigate disparities in access to urban green spaces and how and why the quality of urban green spaces varies geographically across the UK and will consider how to make green spaces more inclusive.

The Committee discussed the health and community benefits that green spaces provide, including the role of green spaces in promoting exercise, how they address environmental health threats such as air pollution and the potential of green social prescribing.

Among the witnesses called to give evidence was Professor Prashant Kumar, Co-Director, Institute for Sustainability at University of Surrey and Principal Investigator and Director at the RECLAIM Network, a UKRI funded ‘one-stop-shop’ for towns and cities to access the information and support needed to install green and blue infrastructure.

Professor Kumar told the MPs that tree planting done well could significantly help. It is not so much number of trees but where they are placed.

‘If you put trees all over London the effect would be negligible. But if you strategically put those trees around the source locations it could reduce the exposure (to nitrous oxides) by more than half’

Research carried out at the University’s School of Sustainability, Civil and Environmental Engineering has already demonstrated that roadside planting can significantly reduce the impact of air pollution from vehicles. However, the size, shape and position of the plants make a big difference to how much pollution is blocked.

Professor Kumar also discussed the wider benefits of green infrastructure – stressing that new parks, waterways and green walls mitigated the impact of flooding, improved mental and physical health, and brought down urban temperatures.

He told the MPs that during last summer’s record-breaking temperatures, wooded areas of Guildford were 13°C cooler than the city centre.

The panel, which also contained Matthew Frith, Director of Policy and Research at London Wildlife Trust and Dr Mark Gush, Head of Environmental Horticulture at Royal Horticultural Society, also explained  how green spaces can mitigate against climate change, their role in countering threats to biodiversity and the impacts of the growing commercialisation of urban green spaces.

They went on to emphasise the need to address a skills shortage in the sector – and spoke of the importance of educating the public on how they can make a practical difference in the area where they live.

Professor Kumar also stressed the importance of academics engaging with policymakers.

‘Public and policy engagement is a really important part of what we do and it was fantastic to engage with Parliament – seeing MPs understand the value of academic research.’