Urban areas planning for climate change
Climate change changes the world’s weather patterns so not only do cities need to focus on reducing greenhouse gas emissions but to also adapt to future climate change and extremes of weather such as flooding and drought.
I will be focusing on how the city of London in England is planning for climate change. 1. Greening London
The government aims to increase the number of open and green spaces in London which not only improves the look and feel of the city, making it more attractive whilst reducing the impact of noise and air pollution. Greening London also makes the city more resilient to flooding and extreme weather events, and can contribute to a healthy mind and body. The Mayor aims to increase tree cover by five per cent by 2025, therefore achieving one tree for every Londoner and creating a better network of interlinked, multi-functional and high quality open and green spaces. 2. Cleaner air for London
Air pollution is a serious health issue which damages the natural and built environment. Actions being taken to improve air quality include introducing the first ever age limit for black cabs tougher standards for the Low Emission Zone, new cleaner hybrid and hydrogen buses and fitting older buses with equipment including filters to curb pollution. The new bus for London, which will be launched in 2012, will use the latest green technology making it 40 per cent more efficient than a conventional double decker. The Mayor is working to introduce more electric vehicles onto London’s streets. In May this year, he launched Source London, the UK’s first citywide electric vehicle charging network and membership scheme. Additional steps are being taken to tackle pollution levels at some of the busiest roads in central London. This includes utilising dust suppressant technology that prevents particulate matter (PM10) from re-circulating, installing green infrastructure to trap pollutants and a no engine idling campaign to reduce engines running unnecessarily when stationary. 3. Protection against Flooding
London is vulnerable to flooding from a variety of sources, key of which are flooding from the North Sea (tidal flooding), the freshwater Thames and the tributaries to the Thames (fluvial flooding) and from heavy rainfall (surface water flooding). Flood risk in London is principally managed by a system of flood defences (walls, gates and the Thames Barrier) and drainage networks. London is currently very well protected against tidal flooding, but has a lower and much more variable standard of protection against fluvial flooding and a relatively low standard of protection against surface water flooding. The probability of all forms of flooding is projected to increase as sea levels rise and heavy rainfall events become more frequent and intense. A large proportion of London’s infrastructure and housing is located on land that is at risk of one type of flooding depending on its location.
There are three key ways to prevent or reduce the impact of flooding: * Spatial planning – This involves avoiding locating flood-vulnerable land uses in high flood-risk areas and identifying where current developments should be removed or exchanged for less flood-sensitive land uses in the future. However, the pressure for development in urban areas means that it is sometimes necessary to develop in flood-risk areas. The GLA and boroughs are responsible for using the planning process to reduce flood risk. The government’s forthcoming review of the planning system must ensure that spatial planning remains the first step in flood risk management. * Flood defences and drainage systems – A significant proportion of London is protected by flood defences. The Environment Agency has responsibility for maintaining most of the tidal and fluvial flood defences, but some riverside landowners also have responsibility for the flood defences on their land and these have to be maintained to the Environment Agency’s standards by the landowners. * Using the public, or private, realm to store, or redirect floodwater – This involves designing areas to deliberately flood (such as parkland, sports fields, public squares, road spaces, or below ground spaces) so that flooding of more vulnerable land uses can be avoided, or reduced. At present, this option is under-utilised in London and many areas of open space could be designed to flood to reduce the risk to built-up areas. 4. Overheating
It is not possible to prevent hot weather from occurring, but it is possible to limit how much the urban realm intensifies hot weather. * It is possible to design new buildings and infrastructure to minimise overheating in hot weather and therefore minimise all but essential mechanical cooling which would otherwise increase the urban island heat effect. For example, building managers can decide to only cool critical parts of a building. Good design, such as minimising solar gain, fitting shutters or shading and increasing green cover can reduce the effect of overheating and particularly the urban heat island effect. In turn, these will reduce the need for air conditioning.