In the UK and around the world there is a growing awareness of the role that cities have to play in mitigating and adapting to climate change.
Cities are concentrations of vulnerability to the harmful impacts of climate change. They are also responsible for the majority of the world’s emissions of greenhouse gasses.
50% of the world’s population lives in cities, a number that is set to increase to 60% by 2030.
For all of these reasons, cities are on the front line in responding to the threats of climate change.
A wide variety of measures are now being considered and piloted. These include schemes to:
- transform urban energy systems
- reduce transport emissions
- retrofit buildings
- conserve water
- build resilience to flooding
- prepare for heat waves
These individual policies need to be implemented as part of an integrated strategy. This will steer cities towards low carbon and well adapted futures.
To do this, we need to understand the processes that are driving long term change in cities and the ways in which they interact.
We recognise demographic, economic, land use, technological and behavioural changes alongside climate change as drivers that will shape the future of cities.
Find out more about:
Urban Integrated Assessment Facility
The Tyndall Centre for Climate Change Research has developed an Urban Integrated Assessment Facility (UIAF). This simulates the main processes of long term change at the scale of whole cities.
The UIAF couples a series of simulation modules within a scenario and policy analysis framework.
It's driven by global and national scenarios of climate and socio-economic change. These feed into models of the regional economy and land use change.
Simulations of climate, land use and socio-economic change inform analysis of carbon dioxide emissions (focussing upon energy, personal transport and freight transport) and the impacts of climate change (focussing on heat waves, droughts and floods).
Integrated assessment tool
The final component of the IUAF is the integrated assessment tool. This provides the interface between the modelling components, the results and the end-user. It enables adaptation and mitigation options to be explored within a common framework.
We've analysed demographic, economic and land use changes. This work has quantified how socio-economic changes determine how hard it will be to reduce emissions. It has also shown how severe impacts of climate change may be.
We've quantified the synergies and conflicts between adaptation to climate change and mitigation of carbon dioxide emissions. For example, we've examined the contribution that urban energy use makes to the urban heat island.
We have used the UIAF to begin to understand how policies can be devised that yield benefits in relation to a number of objectives and avoid undesirable side-effects.
Throughout the course of the we have worked with stakeholders in London. These have included the Greater London Authority, Transport for London, the Environment Agency and Thames Water.
This has helped to understand the problems facing decision makers in London and demonstrate how the UIAF can help to analyse solutions.
We've used datasets that are available in all UK cities. The approach could be used to develop and assess responses to climate change elsewhere in the UK.
Economic drivers of long term changeEconomic drivers of long term change
A multi-sectoral regional economic model has been used to generate long term projections of employment and Gross Value Added in London.
Our base line simulation shows employment in London growing by about 800,000 by 2030. This is driven by demographic changes and changing working practices.
Business and financial services, along with science-based services are expected to grow most rapidly. Heavy industry is diminishing.
Land use changeLand use change
Future patterns of land use between now and 2100 have been simulated for all of London and the Thames Gateway.
The new land use model simulates the effects of changes in employment, the transport network and land use planning policy.
We have simulated four alternative land use futures for London:
- A baseline case, which applied current policies and trends in future.
- ‘Eastern axis’ in which employment opportunities, transport infrastructure development and a preference for lower density living stimulate substantial population growth in east London and the Thames Gateway.
- ‘Centralisation’ in which employment and population growth is concentrated in central London, with a corresponding increase in density.
- ‘Suburbanisation’ in which employment remains strong in central London, but expands into the suburbs, focused on existing hubs (eg Croydon).
To steer land use change away from the baseline towards alternative futures requires major shifts in land use planning, transport connectivity and capacity, and employment opportunities.
Carbon dioxide emissionsCarbon dioxide emissions
We've analysed various scenarios of carbon dioxide emissions. This has included energy use, personal transport and freight transport.
Growth in population, economic activity and mobility are potentially strong upward drivers of emissions.
We've analysed portfolios of emissions reduction policies that are currently under consideration. We've found that more radical policies are required in order to meet the GLA’s target for 60% emissions reductions by 2025.
Their success depends on the availability of carbon-neutral electricity supply and on progressive physical changes to urban form and function.
Heat wavesHeat waves
A new land surface scheme has been introduced into the Hadley Centre’s Regional Climate Model. This is to represent the urban heat island effect.
We used a weather generator adapted from UKCP09. We found that by the 2050s, one third of London's summer may exceed the current Met Office heat wave temperature threshold.
We have analysed the potential for different spatial patterns of development to reduce the risk from heat waves.
- UKCP09 rainfall scenarios for the Thames and Lee catchments
- catchment hydrology models
- imulation of the water resource management system
London is very vulnerable to changes in the surface water regime. This will be increasingly stressed by climate change and population growth.
New storage facilities can maximise exploitation of the surface water resource. On their own they are insufficient in the long term.
They need to be accompanied by vigorous demand management and provision of new resources from desalination or inter-basin transfers.
A model of flooding in the tidal Thames floodplain was used to simulate the effects of sea level rise and changing flows in the river Thames.
This was combined with our simulations of land use changes. These have a profound effect on the magnitude of increase in flood risk in future.
The ‘Eastern Axis’ land use scenario leads to a three-fold increase in flood risk by 2100.
The risk doubles for the ‘Suburbanisation’ scenario.
We have tested the effectiveness of various options to improve flood defences and enhance resilience to flooding when it occurs.
Find out what projects we've been part of.
- Earth observation to capture heatwave dynamics
- Establishing a Long Term Urban Research Facility
- An open source framework for urban modelling
- Transport Analysis for Climate Impact Assessment
- Climate Change Preparedness of UK Urban Areas
- Community Resilience to Extreme Weather
- CityCAT: Urban flood model
- LAYERS – material flows for E-tech elements
Integrated analysis of risks of coastal flooding and cliff erosion under scenarios
R. J. Dawson, M. E. Dickson, R. J. Nicholls, J. W. Hall, M. J. A. Walkden, P. K. Stansby, M. Mokrech, J. Richards, J. Zhou, J. Milligan, A. Jordan, S. Pearson, J. Rees, P. D. Bates, S. Koukoulas, A. R. Watkinson
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Engineering Cities: Tyndall Centre
This report introduces the Tyndall Centre Urban Integrated Assessment Facility and a case study on London.
Download the report (PDF: 1.9 MB).
Non-structural flood management in the Thames Estuary
Richard J. Dawson, Tom Ball, Jonathan Werritty, Alan Werritty, Jim W. Hall and Nicolas Roche
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