Latest UN projections expect the world’s population to grow by 2.9 billion – equal to another China and India – in the next 33 years, and possibly by a further three billion by the end of the century. By then, says the UN, humanity is expected to have developed into an almost exclusively urban species with 80-90% of people living in cities.
Whether those cities develop into sprawling, chaotic slums – with unbreathable air, uncontrolled emissions and impoverished populations starved of food and water – or become truly sustainable depends on how they respond. Many economists argue that population growth is needed to create wealth, and that urbanisation significantly reduces humanity’s environmental impact. Other observers fear cities are becoming ungovernable – too unwieldy to adapt to rising temperatures and sea levels, and prone to pollution, water shortages and ill health.
Many cities are already investing in clean transport and water, sewage, renewable energy, planning, wellbeing and good housing for all. Others face what seem like insurmountable problems.
Projections suggest cities will swell at an astonishing pace – but whether that means our salvation or an eco-disaster is by no means certain.