Cities, pollution and climate change: to what extent can green infrastructure help?
1Urban policies on mitigating climate change and atmospheric pollution need to focus primarily on pollution sources (traffic, transport systems, heating, etc.) rather than the so-called ‘sinks’ (solutions in the form of reservoirs capable of absorbing or countering contaminants but which have a very limited capacity).
2Urban parks, street trees and plants on buildings can act as areas and corridors of clean, cool air in cities and are particularly important due to the lack of available land in urban population centres. Most of these elements serve multiple functions for the three ‘ecosystem’ services in question: air quality, local temperature and carbon sequestering.
3To improve human health in cities it is essential to improve air quality and thermal comfort, aspects on which urban green infrastructure can provide good support at a local level.
4With regard to the mitigation of and adaptation to climate change, local and metropolitan authorities need to foster carbon offsetting beyond their urban boundaries, as this is a challenge on a global scale. Green infrastructure can be employed to impact on transport systems and pollution sources (power stations, large industrial companies, etc.) that are located at a distance from urban population centres.
In urban areas, priority is usually given to infrastructure that contributes to improving the quality of the environment and the health and wellbeing of the urban population. This infrastructure is focused, for example, on air purification, noise abatement and urban temperature control. However, the extent to which green infrastructure can provide these ‘ecosystem’ services effectively depends on numerous structural, functional and environmental conditions.