Over half of the world’s population live in urban areas and this percentage is continually on the rise. Cities and towns are already responsible for over 70% of the world’s energy-related carbon emissions. The city of London is home to 8.17 million residents and hosts 800,000 commuting workers per day (2011 data) leading to heavy energy demand (152,000 GWh of energy was consumed by the city in 2008). The urban heat island effect means that cities are generally warmer than rural areas and take longer to cool down overnight. During heatwaves, such as summer 2003, the temperature difference between the urban and rural areas becomes significant and energy demand for air conditioning dramatically increases. Climate model projections indicate that extreme temperatures will become a regular occurrence by the 2050s. We need to transform London’s ageing urban infrastructure to withstand the 21st century climate, but improvements must be made with energy efficiency and the urban climate in mind.
Changing the urban environment to suit a warmer climate is not a one-way process. Buildings in urban areas don’t just withstand local climate: they change it. This interaction is not generally recognised by engineers and planners working to transform urban infrastructure, partly because the science on which design standards are based does not incorporate understanding of urban climate. Sustainable design of new structures and adaptation of existing buildings for a warmer future needs both legislation and standards – but policy cannot be formulated without evidence. Planning for sustainable cities on the basis of local climate has been hampered by lack of representative data. This is partially due to the difficulties of making representative full-scale measurements in urban areas with traditional, ground-based methods. ACTUAL delivers a platform for the development of remote sensing techniques to provide a cutting-edge solution to the problem.
The research theme over the first five years is the sustainable adaptation of buildings to a warmer London climate. Three interlinked research strands will exploit ACTUAL data within this theme:
- Improving urban climate simulation
- Assessing the effect of building layout on city ventilation
- Developing tools to optimise urban renewable energy generation.
The results of this research will be disseminated amongst engineers, meteorologists, local authority policy makers, and engineering consultants. A Virtual Urban Environment (City-VUE) is currently in development to engage these communities and also to provide much-needed education to schools and the public in the area of urban climate.