If we are to manage the speed and scale of urban growth, as well as the ensuing social, economic and environmental challenges, innovative solutions and research must originate in cities themselves, says an editorial in Nature Geoscience.
City leaders have many reasons to facilitate innovation, says the editorial. But decisions must be backed both by research into the impacts of global change on urban areas and by mitigation strategies at the city level.
By 2070, 70 per cent of the global population will live in megacities, and demand for food and clean water access will be unprecedented. Yet urban environments also help foster human ingenuity — and this is where innovative solutions to future problems are most likely to be found.
The editorial says that city dwellers in developing countries in Asia and Africa currently experience extreme poverty, poor sanitation and a lack of access to clean water. With the number of megacities set to increase, the number of people living in poverty will undoubtedly rise.
Cities, according to one estimate, release more than 70 per cent of energy-related carbon emissions, and produce huge amounts of industrial wastewater and sewage causing eutrophication and acidification of coastal waters.
But their ability to deal with rising temperatures is impaired by, for example, their built-up environment. This stores daytime heat for release at night, which seals the surface from moisture exchange — a phenomenon known as urban heat effect. In addition, their frequent proximity to river deltas makes them vulnerable to sea-level rise. And although white roofing, for example, may help to lower city temperatures, its effect on global temperatures is less certain.
The editorial argues that "research conducted in cities, and on the topic of cities" will help meet the problems of the twenty-first century as well as aiding ten million or so inhabitants to have access to food and clean water.