More people now live in cities than in rural areas
Although migration from rural to urban environments is increasing, cities are not great places to live in a warming world.
Higher urban temperatures are likely to increase the impact of air pollutants from traffic and industry – already a major problem in many cities. Increased sunlight could also lead to more ground-level ozone, which is associated with a wide range of respiratory conditions.
Living in an area suffering from high levels of air pollution could even shorten the life expectancy of the most vulnerable by up to nine years.
In addition, because in cities vegetation has been replaced by buildings, roads and other heat-absorbing infrastructure, urban areas tend to get considerably hotter than surrounding areas – known as the urban heat island effect. As well as increasing the risk of heat-related illnesses, higher temperatures promote the spread of many infectious diseases. The influx of migrants from rural areas can lead to overcrowding and put pressure on health infrastructure and other public services. The spread of shantytowns – makeshift settlements of poor people on the edges of cities in the developing world – creates sanitation problems, increasing the spread of infectious disease.
- Climate change, air pollution and extreme events leading to increasing prevalence of allergic respiratory diseases (2013)
- A report by the UK House of Commons’ Environmental Audit Committee on air quality