|Surface temperature of London at 21:30 on 7 August, 2003 showing the signature of the urban heat island during the killer heatwave. Click to enlarge. Source: NASA|
Boris Johnson, the Mayor of London, launched the London Climate Change Adaptation Strategy—one of the first comprehensive climate change adaptation strategies produced by any major city worldwide. The launch of the strategy comes weeks after the UK Government’s chief scientist advised that the UK needs to adapt to increased average global temperatures of four degrees Celsius.
Expected results of climate change for London include warmer, wetter winters and hotter, drier summers, with more extreme weather (heatwaves, tidal surges and heavy rainfall) and rising sea levels. These changes will increase the risk of heatwaves, floods and droughts, which will affect the prosperity of the city and the quality of life of Londoners.
Adaptation is a dynamic process. As the climate changes, so we must prepare for the impacts and opportunities that will occur. Measures that manage the impacts of our climate today may not provide the same level of protection or opportunity in the future, and so new measures will be needed as different thresholds are reached. There is therefore, no steady state of being ‘adapted’. There is considerable evidence to suggest that we are not actually very well adapted to our current climate—as the impacts of extreme weather regularly highlight.
Adapting to climate change is not about drafting lots of new policies. It is concerned with understanding how climate change may affect the world around us and then routinely integrating that understanding to make better decisions. Decisions about spatial planning and development, social justice, value for money and public safety will all be affected, positively or negatively, by climate change. Decisions with long-term implications will tend to be more affected by climate change as their outcomes will experience more climate change. It is essential that decisions taken today do not constrain adaptation options in the future.—London Climate Change Adaptation Strategy
There are three key high-risk climate impacts for London: heatwaves, floods and drought.
Heat. 600 people died in the 2003 heatwave. A large proportion of London’s population is vulnerable to heat and much of London’s development and infrastructure is not designed for high temperatures.
It is not possible to prevent a heatwave, and as heatwaves do not have a defined physical boundary (like a floodplain), the consequences are felt city-wide.
While it is not possible to prevent a heatwave, it is possible to reduce vulnerable people and asset’s exposure to high temperatures and to reduce their sensitivity. Examples are managing London’s urban heat island through an ‘urban greening program’; designing new, and adapting existing buildings and infrastructure to minimize the need for cooling as far as possible; ensuring that where cooling is still required, low-carbon, energy efficient methods are used; ensuring that recommendations in the Heatwave Plan are implemented.
Flood. 15% of London currently lies in the ‘high’ risk flood zone, including 1.25 million people and extensive public infrastructure. Risk is increasing because of new development on flood plains.
The Mayor will work with the Environment Agency to plan the next generation of tidal flood defences; encourage the restoration of London’s rivers to provide flood storage; and improve the permeability of London’s urban landscape through an urban greening program.
Flood defences can reduce the probability of a flood, but there is always the risk that they might fail and therefore a residual risk exists to the people and assets behind the defences. The Mayor will review the London Strategic Flood Response Plan to identify the key assets at risk. The Mayor will promote flood resilient design for development at highest risk and raise public awareness through an information campaign.
Drought. As with a heatwave, a drought cannot be prevented, but its impacts can be managed.
The Mayor’s Water Strategy proposes a hierarchy of actions: reduce water loss through better leakage management; improve the efficiency of water use in development; use reclaimed water for nonpotable uses; develop water resources that have least environmental impact. The Mayor will work with London Resilience Partnership to review the London Water Shortage Plan.
The potential climate impact on London’s transport network is also significant, the report notes, aside from the immediate impact of flooding on underground and overground rail and other surface transport or high temperatures causing discomfort and danger to passengers. Fluctuating soil moisture content, for example, can cause ground instability on clay soils, cutting embankments and water mains, while thermal expansion of tracks leads to speed restrictions and rail buckling, and melting binder in road material.
The combined effects of climate change could make travel on all forms of transport more uncomfortable and less predictable in the future. The emphasis of the Mayor’s transport policies is to encourage people to use public transport, walk or cycle rather than using their cars, through making public transport accessible, affordable and efficient and walking and cycling pleasant and safe. Anecdotal evidence suggests that extreme weather—high temperatures, rainfall or storminess—discourages people from using public transport, so unless steps are taken to manage the impacts of extreme weather on the transport network, the changing climate could make achieving the Mayor’s ambitions of getting people out of their cars and onto public transport more difficult.—London Climate Change Adaptation Strategy
Transport for London (TfL) is tasked with preparing an adaptation plan for delivering the London Adaptation Strategy across their transport systems. The TfL adaptation plan will:
Undertake a climate impacts risk assessment to identify challenges and opportunities for each of the modes and the integration between the modes;
Improve the resilience of the existing network to the impacts of climate change;
Ensure major procurement contracts (including design, construction and maintenance) consider the impacts of climate change; and
Ensure passenger safety.
We need to concentrate efforts to slash carbon emissions and become more energy efficient in order to prevent dangerous climate change. But we also need to prepare for how our climate is expected to change in the future.
The strategy I am launching today outlines in detail the range of weather conditions facing London, which could both seriously threaten our quality of life—particularly that of the most vulnerable people—and endanger our pre-eminence as one of the world’s leading cities.
London is not unique—all major cities such as New York and Tokyo are at risk from climate change. By producing this strategy, we put London in a position of strength.—Boris Johnson
The Mayor launched the strategy at a visit hosted by the Environment Agency to the Thames Barrier—London’s most famous example of a structure designed to manage the threat of extreme weather.
This strategy will now be open to consultation with the Greater London Authority bodies—the London Development Agency, Transport for London, London Fire and Emergency Planning Authority, Metropolitan Police Authority—and the London Assembly although wider comment from organizations are invited. The Mayor will consider the responses submitted by these bodies and then publish a second version of the strategy for public consultation. The Mayor’s intention is to publish the public consultation draft of the London Climate Change Adaptation Strategy in 2009.