This century will be remembered as the urban century. Our generation will witness the most significant urban growth in human history. By 2050, there will be 2.4 billion more people in cities, a rate of urban growth that is equivalent to building a city with the population of London every seven weeks. Humanity will urbanize an area of 1.2 million km2, larger than the country of Colombia. Cities have been called humanity’s greatest invention, a way of living that can bring many benefits, including increased economic productivity and innovation, greater opportunities for education and individual enhancement, and more efficient use of natural resources and energy. The urban century thus holds enormous opportunity for humanity. However, the Urban Century also presents a challenge to the global environment, both directly through the expansion of urban area and indirectly through urban energy and resource use.
Urban growth is one of the main global issues that the Convention on Biological Diversity (CBD) must address to meet its ambitious goals. Governments must envision a positive natural future for our urban century, a future in which sustainable urban growth occurs in appropriate places while nearby nature is protected, restored, and enhanced. Nature in and near cities is crucial not just for maintaining biodiversity but also for ensuring human wellbeing, which depends on the benefits that nature provides.
This report presents a business-as-usual scenario, which assumes that current urban growth trends continue, and quantifies the impact that urban growth could have on biodiversity and human wellbeing. This report also quantifies the significance of natural habitat for climate mitigation and adaptation. We end by highlighting solutions that can help avoid the negative impacts forecasted under our business- as-usual scenario—ways that governments at all levels can plan and implement a positive natural future for our urban century.