Portsmouth Most Vulnerable to Extreme Heat in Britain

Portsmouth, Leicester, Exeter, Bristol, and Nottingham are identified as the British cities most vulnerable to extreme heat by the end of the century, as global warming intensifies the urban heat island effect. This projection comes from an analysis conducted by Ordnance Survey (OS), in collaboration with the Met Office and the data analysis company 4 Earth Intelligence. The research developed a heat vulnerability index for all cities across Great Britain, assessing their susceptibility to rising temperatures.

Portsmouth, a coastal city in southern England with a population of approximately 208,000 residents, has been identified as the most vulnerable to extreme heat both currently and in future projections. The urban heat island effect describes how built-up areas, characterized by concrete and asphalt, absorb and retain more heat than surrounding rural areas, leading to significantly higher temperatures within cities. This phenomenon is exacerbated by climate change, which is causing global temperatures to rise.

The OS heat vulnerability index considers various factors to determine a city's susceptibility to extreme heat. While the specific methodologies and data points used in the index are detailed in the full research, the identified cities are expected to experience the most pronounced warming. This increased heat poses significant risks to public health, infrastructure, and the environment within these urban centers. For instance, higher temperatures can lead to heatstroke, exacerbate respiratory and cardiovascular conditions, and increase energy demand for cooling.

The collaboration between OS, the Met Office, and 4 Earth Intelligence highlights the growing need for data-driven approaches to understand and mitigate the impacts of climate change on urban environments. The Met Office, the United Kingdom's national weather service, provides crucial climate data and projections, while 4 Earth Intelligence contributes expertise in data analysis. Ordnance Survey, responsible for mapping and geospatial data in Great Britain, leverages its comprehensive datasets to inform this critical research. The findings underscore the urgency for cities to develop and implement adaptation strategies, such as increasing green spaces, improving building insulation, and establishing early warning systems for heatwaves, to protect their populations and infrastructure from the escalating threat of extreme heat.