Why scaling up sustainable urban growth is critical for the planet

In 2010, we quietly crossed a global threshold: The majority of the world went from living in rural areas to living in cities. As with foreign direct investment flows and the rise of atmospheric carbon-dioxide concentrations, this shift is a reminder that we live among imperceptible but significant megatrends.

By 2050, it is estimated that 70 percent of all people will live in cities, and the infrastructure needs to accommodate them and sustain this growth are massive, requiring a delicate balance of social, environmental, and economic considerations. As we have seen, urbanization can take multiple paths -- sometimes resulting in cities that thrive, and other times creating cities with multiple tiers of poverty and disparity.

These trends make the case for sustainable urban growth appealing: We need to invest in sustainable infrastructure now because the lead times are long, the capital expenses high, and the systems that enable a lower per capita social and environmental footprint today will have exponential savings tomorrow. While the logic is sound, the growth of sustainable infrastructure has not kept pace with the need.

Over the past few weeks, I’ve had a chance to speak with several individuals in the private sector who are at the forefront of infrastructure development and who have shared their views on the challenges that business faces and what needs to change to make sustainable urban growth attainable.

Megacities: The future of urban growth

  • In 25 years, half of the world's population will live in emerging market cities.
  • Of the 25 fastest-growing major cities, seven are in China, six are in India, and none is in developed countries.
  • Per capita economic activity increases 10 percent with every 5-percentage-point increase in urban population.
  • By some estimates, cities are responsible for 80 percent of global carbon-dioxide emissions.

City focus

The conversation about opportunities to create sustainable cities has intensified over the past couple of years. One such effort, the CDP Cities project, allows cities to report carbon inventories in a similar model to the organization’s widely used corporate climate disclosure platform. CDP Cities usefully built off the C40 Cities project, led by a group of like-minded city mayors with a long-term vision for energy reduction. Similar to the corporate-reporting platform, CDP Cities is a way to identify and manage risks and opportunities while creating the accountability to demonstrate improvements to a variety of stakeholders, including investors.

Next page: Ranking cities by environmental factors