Climate change
The emissions arising from constructing, heating, cooling and servicing buildings are recognised as significant factors that contribute to global climate change. Climate change in turn presents a number of risks to buildings and the built environment in general, with many revolving around the water environment and cycle. The effects of climate change therefore provide further incentive for Integrated Water Management.
Climate change projections for Hertfordshire forecast an increase in average temperatures and an increase in the number of extreme weather events. Hertfordshire County Council commissioned a Climate Change Risk Assessment using the latest UK Climate Projections (UKCP09). The headline messages from the Risk Assessment are provided in the Climate Change Adaptation module, but key findings included:
- General precipitation - More variable patterns of rainfall and snow, which is anticipated to result in drier summers, increased rainfall during the winter, and more frequent severe weather.
- Extreme rainfall - More intense rainfall falling in winter months. Towards the end of the century rainfall on the wettest day in winter could increase from 2009/10 levels by up to 56%.
Both of these may result in increased flooding episodes, particularly in urban areas.
Less rainfall is expected during the summer months; however, a prolonged period of dry, hot weather causes the ground to dry, which reduces its ability to allow water to infiltrate quickly enough when a short but heavy rainfall event does occur. The resulting excess water run-off can lead to flash flooding, particularly where there are also impermeable man-made surfaces. For instance, the hot summer of 2006 triggered thunderstorms and torrential rain which caused localised flooding across England. The town of Royston, North Hertfordshire suffered from flash flooding that blocked roads and caused damage to properties.
More information on reduction greenhouse gas emissions from the built environment, and on how to adapt the built environment to climate change impacts can be found in the Energy and Climate Change Adaptation sections of the Climate Change module.