The Head of Planning was in attendance to provide the Panel with information on how planning could take into consideration the potential impact of new development on air quality. In addition, information in relation to using tree planting to absorb pollutants was presented by the Senior Area Care Manager.
In terms of air pollution and the planning service there were two ways in which interaction took place. When an application was made for development, the location to source of air pollution had to be taken into consideration. For example, building office or residential accommodation next to a main road. Applicants would need to demonstrate that a scheme could be accommodated without detriment to the inhabitants of those premises and air quality surveys would be part of the process. With regard to the developments themselves, some would lead to increased traffic movements, and other recognised sources of air pollution to different degrees including heat and light sources, which needed to be mitigated.
One of the ways of mitigating potential air pollution was through design and development so that good access to open spaces, recreation, facilities and public transport were included to minimise the use of private cars. Particularly in larger developments, the inclusion of significant landscaped areas and woodland planning. Trees had a role to play in capturing carbon as well as the physical and economical elements they provided.
Middlesbrough Council was currently in the process of developing a new Local Plan which and a number of policies would be included to mitigate air pollution. Following direction from Central Government, for the first time reference was made to the inclusion of electric car charging points in homes. As more and more people bought electric cars it was anticipated that Developers would look to provide them in residential homes as well as town centre office developments.
When trees were removed as part of a new development they were not necessarily replaced like for like but more planting might be required to make the development more attractive. Usually if a tree died within five years it would be re-planted but unless there was a Tree Preservation Order (TPO) on it, replacement could not be enforced. Future developments were more likely to contain clumps of trees or an area of woodland rather than planting close to houses. It was also important to specify native species that would not dominate. In the past when trees where included in developments they had been planted within the curtilage of properties so that the Council did not have to maintain them. However, this also meant that the house owners could remove them.
In terms of woodland planting there was also a better mortality rate rather than planting on verges. Native species always survived better than foreign ones although they also played an important role in planning. They could be hybridised more easily so as to avoid potential issues such as sticky deposits.
There were an estimated 100,000 trees in Middlesbrough which included: 14,000 verge planted, 10,000 in parks in cemeteries, 10,000 in open spaces and 65,000 in woods and copses. Approximately 26% of Middlesbroughs tree stock were species highly recommended by the Woodland Trust for absorbing pollutants including carbon dioxide, nitrogen dioxide, sulphur dioxide and particulates. Recommended species included: Elm (Ulmus), Common Ash (Fraxinus), Limes (Tilias), Maples (Acer), T Oaks (Quercus)
and Ginkgo (Ginkgo).
Middlesbrough Council had the following highway trees:
Maples 1507 10.7%
Limes 1357 9.6%
Ash 784 5.6%
Elm 38 0.2%
Turkey Oak 10 0.07%
Ginkgo 0 0%
It was highlighted that trees could also help pollution by other means. London Plane had microscopic Velcro-like hooks on the underside of their leaves that captured airborne pollutants. Others such as Maples and Limes secreted a sticky mildew substance that could also help trap airborne pollutants.
A standard tree could absorb 13 pounds of CO2 per year and became most productive at carbon absorption at around ten years old. A standard large tree could supply enough oxygen for four people each day. About 28% of all oxygen was produced from plants, including rain forests. The greatest percentage of oxygen was actually supplied by marine life.
Due to historical austerity measures, Middlesbrough Council did not have a policy of planting trees. However, when requests were made to plant on Council land, this was not usually refused. A standard tree from a local supplied cost between £120 and £160 to plant and this rose to £250 to cover planting and maintenance costs. Middlesbrough was a compact area with about 1% tree cover overall. The aim was to increase that figure through future developments not only for improved air quality but also ecological benefits. It was also highlighted that where sites were earmarked for development in the Local Plan, it might not necessarily be a good idea to plant there in the interim as established woodland could become a barrier to future development.
It was important for the Council to work with community groups, schools and Woodlands Trust to continue tree planting. The Woodland Trust would provide grants to anyone to plant up to 100 trees. The Council actively encouraged more tree planting and worked with groups including the Green Space Forum headed by Natural England, Fairy Dell and the Friends of Bluebell Beck.
1. The information provided was received and noted.
2. The Senior Area Care Manager would provide a Ward-by-Ward breakdown of the number of trees planted in Middlesbrough.