City-scale integrated assessment of climate impacts, adaptation and mitigation

Transcription

1 City-scale integrated assessment of climate impacts, adaptation and mitigation J.W. Hall, R.J. Dawson, S.L. Barr, M. Batty, A.L. Bristow, S. Carney, A. Dagoumas, A. Ford, C. Harpham, M.R. Tight, C.L. Walsh, H. Watters, A.M. Zanni Tyndall Centre for Climate Change Research, UK. ABSTRACT Worldwide, cities are faced with the challenge of designing and implementing the transition to a state in which their greenhouse gas emissions are drastically reduced and they are well adapted to the impacts of climate change. There is increasing understanding of the synergies and conflicts in the objectives of mitigation and adaptation. These interactions are no more vivid than in urban areas, where they play out through land use, infrastructure systems and the built environment. Urban decision makers need to understand the implications of these interactions and the potential influences of future global changes. With these decision makers in mind, the Tyndall Centre for Climate Change Research has for the last three years been developing an Urban Integrated Assessment Facility (UIAF) which seeks to simulate socio-economic change, climate impacts and greenhouse gas emissions over the course of the 21 st century. The research is focussed upon London, UK, a city that has taken a lead role in the UK and globally with respect to climate protection. In this paper we describe the concept and various components within the UIAF and summarise some of the insights that have been garnered from this novel integrated analysis. INTRODUCTION Responding to climate change by mitigating greenhouse gas emissions and adapting to the impacts of climate change is placing new and complex demands upon urban decision makers. Against a background of rapid socio-economic change, decision makers are now called upon to develop strategies for climate change mitigation and adaptation. Targets for mitigation of greenhouse gas emissions are now urgent and imply major reconfiguration of urban energy systems, transport and the built environment. Meanwhile, adaptation of urban areas requires integrated thinking that encompasses a whole range of urban functions. The climate drivers that adaptation is responding to will 1

2 amplify over a period of decades but manifest themselves most vividly in the form of intermittent extreme climate shocks of windstorms, floods, droughts or heat waves. The timescales scales of change and the variability associated with the change signal are quite out of step with most political decision making processes. Mitigating and adapting to climate change in urban areas involves complex interactions of citizens, governmental/non-governmental organisations and businesses. This complexity can inhibit the development of integrated strategies (which may involve demand management, land use planning and construction of new civil infrastructure) whose combined effect is more beneficial than the achievements of any single agency or organisation acting unilaterally. There is increasing understanding of the synergies and conflicts in the objectives of mitigation and adaptation (McEvoy et al., 2006). These interactions are no more vivid than in urban areas, where they play out through land use, infrastructure systems and the built environment. Without sensible planning, climate change can induce energyintensive adaptations such as air conditioning or desalination, driving higher emissions. Urban decision makers need to understand the implications of these interactions and the potential influences of future global changes. If they can test, through simulation, alternative policies and assess them from a multi-attribute point of view, they are more likely to avoid the mistakes of the past. Whilst the objectives of mitigation and adaptation are clear and well aligned with the broader aims of sustainable development, the process of designing transitions to sustainability in urban areas is much more complex. In practice these objectives will achieved by a myriad of local actions set within a broad policy framework. On the other hand, certain large scale infrastructure and planning decisions are essential elements within the portfolio of measures that need to be put in place as part of a transition strategy. We therefore regard cities as complex adaptive systems over which decision makers with responsibility for urban development have only partial control. Because of strong path-dependent processes, the present urban configuration can only be understood in the context of past development and so, by the same token, future 2

3 development options are modulated by existing development on the ground and development trajectories. It is our contention that the processes of influence and interaction within urban areas are so complex that they increasingly defy the ability of individual decision makers to assimilate all of the relevant information and reached strategic decisions. Whilst the aspiration for integrated responses to the challenges facing urban areas is widely articulated, in practice the complexity of integrated approaches may inhibit effective decision making. There is therefore a need for methods and tools that can help to facilitate and inform integrated assessment. Quantified integrated assessment is one such approach and is the subject of this paper. Integrated assessment has been applied to a wide variety of different systems and at a range of different spatial and temporal scales. Here our attention is upon cities and the timescale of appraisal is taken as being up to a century into the future. Our interest is in long term processes of change and on how climate-related drivers inter-play with other drivers (for example demographic and economic) over these timescales. This extended timescale coincides with the typical time frame for assessment of climate change policy. An extended time-frame is also motivated by the long life of infrastructure systems and the extended legacy of planning decisions. It is these major planning and design decisions that we are seeking to inform so as to avoid decisions with consequence that are materially regrettable or foreclose the opportunity for alternative actions in future. Of course on this timescale there are major uncertainties, so the integrated assessment approach has to be set within an appropriate uncertainty framework. If we are to understand processes of change on extended timescales, then it is usually also necessary to analyze them on extended spatial scales. Here our analysis is on the scale of whole cities, as it is on that scale that patterns of spatial interaction are most vivid. However, framing the city in this way brings inevitable boundary problems. Thus we seek to represent the economic and transport interactions between the metropolis and the surrounding region and nation. In fact to analyze water resources and flooding we must examine the whole of the surrounding river basin, together with inter-basin 3

4 transfers where they exist. Other aspects of urban climate require a nested approach to downscaling from the global climate. The boundaries that we set are therefore multiple and non-coinciding, though they all have a certain rationale. The approach we describe in the following is work in progress. A first phase of development, which is now approaching completion, has set in place all of the main components that are required for an integrated assessment of mitigation and adaptation in urban areas. The work is now being used in practice to help inform decision making in London. However, there is almost endless scope for refinement. Some of the most promising possibilities are mentioned at the end of this paper. What has been show so far is that it is both possible and informative to look at cities in a quantified integrated way over a timescale of decades. Furthermore, this analysis is proving to be of value in stimulating more integrated thinking about cities and informing complex decision making problems. THE TYNDALL CENTRE URBAN INTEGRATED ASSESSMENT FACILITY In response to the challenges set out above, in 2005 the Tyndall Centre for Climate Change Research launched a research programme on climate change in cities, which is developing a quantified integrated assessment model for analysing the impacts of climate change on cities and their contribution towards global climate change in terms of their greenhouse gas (GHG) emissions. On the scale of large cities it is meaningful to think about climate impacts, adaptation and mitigation in the same quantified assessment framework. This is a scale at which strategies for mitigation and adaptation can be usefully designed and assessed. It is increasingly also the scale at which individual civil servants in city administrations are being given responsibility for climate protection. Yet urban climate mitigation and adaptation policy and behaviour can hardly be divorced from its global context. A nested approach, in which a wide range of global climate, economic and demographic scenarios are taken as the boundary conditions for the integrated assessment, has therefore been adopted. The overall structure for the integrated assessment is shown Figure 1. Each element is descried briefly now and in more detail in the following sections. At the top of the figure 4

5 are the socio-economic and climate scenarios that form the boundary conditions for the analysis. A process of down-scaling generates climate scenarios at the city scale as well as economic and demographic scenarios for the urban area. This provides the boundary conditions for the city scale analysis, in this case study of London. These boundary conditions drive scenarios of regional economy and land use change, ensuring that whilst they are influenced by local policy, these scenarios are also globally consistent. It is at the level of land use modelling that the analysis becomes spatially explicit. The spatial resolution of analysis may vary according to the process or impact being considered, which may require additional downscaling. Thus, for example, analysis of spatial interaction takes place at a ward-scale, but is then downscaled to a 100m grid to enable analysis of climate impacts. Within the bounds of a given global scenario, national or city-wide economic, transport and land use policy can be tested, which does not necessarily have to coincide with the global scenario trajectory. Scenarios of land use and city-scale climate and socio-economic change inform the emissions accounting and climate impacts modules. Emissions accounting and climate impacts assessment are informed by scenarios of economic and land use change, whilst being consistent with scenarios of climate change. Adaptation and mitigation scenario developed within the integrated assessment must be consistent both internally and within the broader context of global change scenarios (e.g. the technologies that may be adopted to mitigate transport emissions at a city scale cannot exceed the assumed level of technological advancement in the global scenario). The integrated assessment considers a finite number of scenarios of global climate change, but allows a more diverse range of city-scale scenarios to be explored. The final component of the framework is the integrated assessment tool that provides the interface between the modelling components, the results and the end-user. To maximise the number of policy questions that can be tested, the models must be implemented such that results are rapidly computed. This can be achieved using a number of approaches including: use of rapid and/or low-complexity models, pre-running a wide range of scenarios and storing the outputs in a database and the construction of model emulators. 5

6 The framework set out in Figure 1 is intended to be generic for climate impacts and GHG emissions analysis at a city scale. The component models presented in subsequent sections are also generic in that they can, and in most cases have, been demonstrated on other case study sites. Figure 1 Overview of the integrated assessment methodology for greenhouse gas emissions and climate impacts analysis at a city scale GREATER LONDON AND THE THAMES GATEWAY London is the capital city of the United Kingdom and has been a settlement for around two millennia. It has a wide and diverse cultural, social, economic, environmental and built heritage and is one of the most culturally diverse cities in the world with 29% of the population from ethnic minorities, speaking almost 300 languages (ONS, 2003). The population is currently approximately 7.2million and is expected to be over 8.1million by 2016 (GLA, 2004). The London Plan (GLA, 2004) is the strategic plan developed by the Greater London Authority (GLA) setting out an integrated social, economic and environmental framework for the future development of London for the next years. The plan provides the London-wide context within which individual boroughs (local administrative authorities, of which there are 33 in London) must set their local planning policies. The general aims for London are to: Accommodate growth within current boundaries without encroaching on open spaces; Make London a better city to live in; Strengthen and diversify economic growth; and Increase social inclusion and reduce deprivation. Improve accessibility through use of public transport, cycling and walking (i.e. reduce use of cars, though airport, port and rail infrastructure are likely to be increased); 6

7 Make London a more attractive, well-designed green city through improved waste management, re-use of brownfield sites, increased self-sufficiency and improved air quality. Figure 2 Zones of development in London and the Thames Gateway The London Plan sets our areas that are targeted for development, with an emphasis upon development of previously developed land and upon certain areas that are targeted for regeneration (Figure 2). The metropolitan area of London extends beyond the boundaries of the GLA. Of particular significance is the zone of development east of London known as the Thames Gateway (Figure 2), which includes many previously industrialised areas that are now under-developed but benefit from being quite close to central London and from good transport links. In the UK, the southeast of the country stands out as being particularly vulnerable to climate change and also, because of the concentration of population and transport activity, a focal point of greenhouse gas emissions. The southeast of England is the most water scarce region in the UK, having lower than average rainfall and a very large demand (Environment Agency, 2007). Isostatic subsidence means that southern Britain has and will experience faster relative sea level rise than in the north. The southern North Sea has always been subject to storm surges, and whilst the evidence for future changes in surge processes is ambiguous, when superimposed in increased mean sea level, the risk of surge flooding will increase (Evans et al., 2004). Because of its geographical location in the warmer part of the UK and very widespread urbanisation, London does suffer from urban heat and associated air quality problems (London Climate Change Partnership, 2002). The London Underground metro system was not designed for these hot conditions and is particularly problematic. Responding to these challenges requires a portfolio of measures that may involve reversal of entrenched patterns of demand and development. The need to adapt to climate change may conflict with the demands of mitigation (Klein et al., 2003). Thus, for example, intolerable urban temperatures increase energy demand for air conditioning, which in turn also increases heat emissions into urban areas, exacerbating 7

8 the problem. Action to tackle climate change needs to be set in the broader context of sustainability, including issues of resource use, human wellbeing and biodiversity (Najam et al., 2003). It is clear that both mitigation and adaptation will involve putting together portfolios of measures in a strategic way. Only some of those measures are actually in the power of the GLA to influence. Many relevant instruments (such as duties on fuel, utility pricing and the generation mix for national grid electricity generation) are in the hands of central government or privatised utilities and industry regulators. Local planning decisions meanwhile are administered by the London boroughs. However, the GLA s strategic planning responsibility does provide opportunities to reduce emissions and climate vulnerability through land use planning. Responsibility for the roads and public transport (via Transport for London) provides strategic responsibility and opportunity for dealing with transport emissions and local air quality. Flooding in urban areas is subject to rather complex administrative arrangements in the UK (Pitt, 2008), but responsibility for tidal flooding and flooding from the river Thames and its tributaries rests with the Environment Agency. Similarly, water resources are planned and managed by negotiation between the privatised water utilities, the water regulator (OFWAT) and the Environment Agency. Amidst this rather complex institutional landscape it is necessary to put together various coalitions of stakeholders in support of initiatives in particular sectors. This involves developing common understanding of various intersection problem domains. At the same time a strategic approach is required if there is to be a realistic prospect of achieving high level objectives for mitigation and adaptation. The integrated assessment under development in the Tyndall Centre for Climate Change Research is intended to quantify these issues so as to provide evidence to inform policy decision making. The following sections describe, with the help of some indicative demonstration datasets and outputs, how the integrated assessment is being constructed and what its capabilities will be when it is completed. 8

9 ELEMENTS OF THE INTEGRATED ASSESSMENT Regional economic modelling A regional economic model is used to provide the quantified economic scenarios that are the starting point for analysis of vulnerability and greenhouse gas emissions. The Multisectoral Dynamic Model (MDM) (Barker and Peterson, 1987; Junankar et al., 2007) has been adopted for the integrated assessment in London. This is a coupled macro-economic model in the sense that it models the whole economy, but is multisectoral, so predicts output from and employment in 42 different industrial sectors. The version of the model used in this assessment contains each of the regions in the UK (including Greater London) as well as the rest of the world. MDM is a model of growth and fluctuations over the medium and long term, so is well suited to the task of providing internally consistent scenarios for the purposes of integrated assessment. The model is dynamic, providing intermediate results at timesteps over the simulation period. It takes as its inputs baseline projections of long term growth and population, as well as past observations of the relationships between different industrial sectors. MDM has been used since the 1980s to provide economic forecasts for the UK economy, so has benefited from a process of ongoing testing and validation. Providing projections for the timescale used in this analysis is obviously particularly testing, so the outputs of the type shown in Figure 3 should be taken as being scenarios. These scenarios do however have the attraction of providing internally consistent projections, which account for inter-sectoral interactions and temporal dynamics. These provide inputs to the land use model and the emissions accounting models described below. Figure 3 Employment projections for London, comparing outputs from the MDM model (labelled Tyndall ) and figures used by the GLA. Industrial activity has been aggregated into 5 sectors. 9

10 Land use change modules Future vulnerability to climate change and demand for greenhouse-gas emitting services are closely linked with land use patterns in the urban area. Moreover, spatial analysis of greenhouse gas emissions can help to target mitigation action and may also be a requirement for analysis of air quality and anthropogenic heating contributions to the urban heat island. Central, therefore, to the UIAF are modules for development of scenarios of land use change over the coming decades. The starting point for this analysis is the current configuration of domestic and commercial land use, along with census data. The evolution of land use from the current configuration into the future is analysed on the basis of a number of drivers and constraints. The multi-sectoral employment scenarios discussed above are disaggregated to provide spatial scenarios of future employment. Access to employment provides the main driver for development of new residential property. Generalised travel cost has been analysed for five modes (road, bus, rail, light rail, underground metro) to and from each of the 801 wards (see for example Figure 4). The generalised travel costs have been modified to represent planned transport infrastructure investment (including Crossrail, a new east-west underground mass transit link) and also to incorporate various scenarios of transport infrastructure development looking further into the future. These travel costs are incorporated in a spatial interaction model, alongside information on existing land use and land available for new residential development, in order to develop future distribution of employed population and their dependents. Figure 5 illustrates the projected change in residential population at a ward scale for a high growth scenario. In practice, patterns of commercial and residential land use will be constrained by planning policies, which may, for example, prevent development on recreational land. On the other hand, planning policy may actively seek to promote development in particular areas, for example brown field sites of previously developed industrial land. These additional constraints and attractors can be applied to the spatial interaction model, with varying degrees of policy effectiveness. Figure 6 illustrates a population change scenario subject to existing constraints upon land use and attractors for specified regeneration zones. 10

11 Figure 4 Example of generalised travel costs by car (in minutes) from Heathrow ward. Note the influence of the congestion charging zone in central London on travel cost. Figure 5 Projected population change to 2100 at a ward scale (high economic growth, unconstrained development) Figure 6 Projected population change to 2100 at a ward scale (high economic growth, constrained development) The spatial interaction model described has been developed at the scale of wards, across the whole of London (and the Thames Gateway). This keeps the analysis of interactions to a manageable 801 zones (633 for London and 168 for the Thames Gateway). However, for climate impacts analysis, it is necessary to higher resolution scenarios. A module that disaggregates land use proportions at ward scale onto a spatially explicit 100m grid has therefore been developed. This module combines a series of weighting and constraint functions. The weighting functions seek to locate residential properties near to existing residential development, transport links and schools, whilst applying any local planning constraints. Figure 7 shows the results of the disaggregation algorithm for one ward in east London (South Hornchurch) under two different scenarios population change. In both cases, development on brownfield sites is encouraged. Figure 7 Two scenarios of disaggregated residential development (blue grid boxes) in 2020 in the South Hornchurch ward. Red boxes denote existing residential land cover. Left hand panel is for low economic growth. Right hand panel is for high growth. Climate impacts and adaptation analysis The climate impacts analysis currently focuses on the three most important potential impacts of climate change in London: flood risk, water availability and heat waves. Analysis of each of these risks involves consideration of both the probability and consequences of harmful climate-related events. Scenarios of relevant climate variables are based upon existing GCM and regional climate model outputs, which are further downscaled as necessary. Analysis of flood 11

12 risk is based upon analysis of surge tides in the Thames estuary and flood flows in the river Thames. For the time being flooding due to extreme rainfall within the urban area (pluvial flooding) and flooding in the tributaries of the tidal Thames have not been analysed. Surge tide frequency will increase due to projected changes in regional timemean sea level (which is projected to be in the range in 2095). Potential for increasing frequency of cyclonic events that lead to surge tides in the southern North Sea has been hypothesized (Lowe and Gregory, 2005) but recent analysis by the Met Office Hadley Centre indicates no significant trend in surge frequencies over the 21 st Century. Analysis of fluvial flood frequency has made use of downscaled regional climate model scenarios, propagated through a hydrological model of the Thames catchment. A similar approach has been used to assess water availability under different scenarios of climate change. Analysis of heat in the urban area is based upon a combination of existing temperature measurements in the urban area and a new version of the Met Office Hadley Centre s regional climate model, which includes the effects of the urban land surface. Figure 8 shows the pattern of maximum daily temperatures (now and in the 2050s), averaged over the summer (June, July, August) season, which clearly illustrates the amplification of temperatures in central London and around Heathrow airport. The model includes scenarios of anthropogenic heat emissions from the urban area. Figure 8 Daily maximum temperature for London averaged over the summer season (June, July, August): present day (left) and 2050 (right) The impacts of climate change will often be felt in terms of the changing frequency of damaging extremes. Climate impacts are therefore typically measured in terms of changing average annual losses, which involves integrating over the extreme value distribution of the climate variable(s) of interest. These distributions are combined with damage functions (for example relating flood depth and duration to economic damage). These metrics of vulnerability will change in future, due to changes in the economy and land use. The economic and land use modelling describe provides insights into how vulnerability will change looking into the future. 12

13 Figure 9 provides projections of the number of people at risk from tidal flooding, under different development scenarios. Efforts to prevent development in the floodplain are clearly effective at limiting the growth in flood risk, but are probably unrealistic because so much of the land that is available for development is located in the floodplain. Interestingly, the two planned development scenarios give a greater increase in flood risk than the unconstrained development scenario, because of the emphasis in planned development upon redevelopment of brown field site, which in many instances are located in the floodplain. Figure 9 Tidal flood risk in London (expressed as expected annual damage) for different scenarios of land use change Having established a platform for development of future scenarios of climate impacts it should be clear how this can then be used to test adaptation options. These can include measures to reduce the probability of harmful events (for example by provision of new water supplies of water) or measures to reduce the impact should harmful climatic events occur, for example through changes to building design to make them more comfortable during high temperatures. Emissions accounting Alongside projections of climate impacts, the integrated assessment is also designed to provide projections of greenhouse gas (GHG) emissions. The estimation of greenhouse gas emissions is based upon the same demographic and economic projections that have been described previously. The emissions accounting tool associates GHG emissions with various levels of economic activity and population (Figure 10). These can be further disaggregated spatially based upon existing and future patterns of spatial development. Figure 10 Projections of GHG emissions for London based upon a baseline economic growth scenario with no new mitigation policies Special modules have been developed for generation of GHG emissions scenarios from personal and freight transport. Various policies in relation to infrastructure (loading 13

14 bays, preferential lanes, consolidation centres, capacity) regulation (delivery restrictions, road user charges, low emission zones), technology (bio-fuels, hydrogen, electrical vehicles), efficiency (driver behaviour, delivery servicing plans) and modal switching have been tested. In general these demonstrate that whilst technological and efficiency measures can help to mitigate growth in GHG emissions, substantial reductions in GHG emissions are only achievable by constraining demand. The accounting methodology is coupled with a scenario analysis tool to enable users to explore the impact of different scenarios of energy demand, technology change and portfolios of the methods of energy generation used to supply the city. A key feature of the emissions accounting analysis is the ability to explore the cumulative emissions reductions necessary in order to achieve a given emissions reduction target. SUPPORTING DECISION MAKING The analysis described above has been brought together in an integrated assessment tool. The purpose of the tool in the first instance has been to enable the research team to conveniently generate and display results, as part of the testing and verification of model. Figure 11 shows a screen shot from the user interface. It can be used to display maps and graphs of variables of interest. Figure 11 Screen shot from the user interface of the assessment tool Besides providing a convenient tool for generating research results, the integrated assessment tool is now being used to provide new scenarios for the GLA. To this end an extended range of scenarios and policy options are being developed. CONCLUSIONS The Tyndall Centre s Urban Integrated Assessment Facility (UIAF) brings together long term projections of demography, economy, land use, climate impacts and GHG emissions within a coherent assessment framework. It thereby provides the basis for examining at the scale of whole urban systems the effect of adaptation and mitigation decisions, with a particular emphasis upon decisions with an extended legacy. The UIAF is now being used to help inform decision making surrounding the new London Plan. 14

15 There are inevitable limitations to the number of process and interactions that can be included in a broad scale assessment of the type described here. However, tackling mitigation and adaptation at a system scale does provide the potential to understand system interactions in a way that is not achievable in sector specific assessments. In this paper we have illustrated the implications of land use planning decisions in relation to climate vulnerability, in particular in relation to flood risk. We have presented in outline the water resources and temperature assessment modules. The GHG emissions assessment for London shows projections of steadily increasing emissions from industry, domestic and transport sources unless vigorous measures are set in place to mitigate emissions. The feedback of climate impacts into the economy and land use have been targeted as priority area for future research. These two aspects will be address in the UK Engineering and Physical Sciences Research Council funded project ARCADIA (Adaptation and Resilience in Cities: Analysis and Decision making using Integrated Assessment) which is now under way. ACKNOWLEDGEMENTS The research described in this paper was funded by the Tyndall Centre for Climate Change Research REFERENCES Barker, T. and Peterson, W. (Editors), The Cambridge Multisectoral Dynamic Model of the British Economy. Cambridge University Press, Cambridge. Environment Agency, Water for the Future: Managing water resources in the South East of England A discussion document, Environment Agency, Bristol. Evans, E.P. et al., Foresight Flood and Coastal Defence Project: Scientific Summary: Volume I, Future risks and their drivers, Office of Science and Technology, London. GLA, The London Plan, Greater London Authority London. Junankar, S., Lofsnaes, O. and Summerton, P., MDM-E3: A short technical description, Cambridge Econometrics, Cambridge. Klein, R.J.T., Schipper, E.L. and Dessai, S., Integrating mitigation and adaptation into climate and development policy: three research questions, Tyndall Centre for Climate Change Research. 15

16 London Climate Change Partnership, London Climate Change Partnership: A Climate Change Impacts in London, Evaluation Study, Final Report. Lowe, J.A. and Gregory, J.M., The effects of climate change on storm surges around the United Kingdom. Philosophical Transactions of the Royal Society London, 363(1): McEvoy, D., Lindley, S. and Handley, J., Adaptation and mitigation in urban areas: synergies and conflicts Municipal Engineer 159 (4): Najam, A., Rahman, A.A., Huq, S. and Sokona, Y., Integrating sustainable development into the Fourth Assessment Report of the Intergovernmental Panel on Climate Change. Climate Policy, 3(S1): S9-S17. ONS, Focus on London (D. Virdee, T. Williams (Eds.), Office of National Statistics, Newport. Pitt, M., Learning Lessons from the 2007 Floods, Cabinet Office, London. 16

17 Figure 1 Overview of the integrated assessment methodology for greenhouse gas emissions and climate impacts analysis at a city scale 17

18 Figure 2 Zones of development in London and the Thames Gateway Figure 3 Employment projections for London, comparing outputs from the MDM model (labelled Tyndall ) and figures used by the GLA. Industrial activity has been aggregated into 5 sectors. 18

19 Figure 4 Example of generalised travel costs by car (in minutes) from Heathrow ward. Note the influence of the congestion charging zone in central London on travel cost. Figure 5 Projected population change to 2100 at a ward scale (high economic growth, unconstrained development) 19

20 Figure 6 Projected population change to 2100 at a ward scale (high economic growth, constrained development) Figure 7 Two scenarios of future residential development (blue grid boxes) in Red boxes denote existing residential land cover. Left hand panel is for low economic growth. Right hand panel is for high growth. 20

21 Figure 8 Daily maximum temperature for London averaged over the summer season (June, July, August): (left) and 2050s (right) Figure 9 Population at risk from tidal flood risk in London for different scenarios of land use change 21

22 Figure 10 Projections of GHG emissions for London based upon a baseline economic growth scenario with no new mitigation policies Figure 11 Screen shot from the user interface of the assessment tool 22