Buildings & Cities

Cities are a key place to innovate to reduce greenhouse gases

The world is currently undergoing the largest wave of urban growth in human history.

More than half of the global population is now concentrated in urban areas, a proportion that is expected to increase to nearly 70% by 2050. [33]

Because nearly all the world’s largest cities—and 40% of all other major cities—are located along coasts, these population centers are especially at risk from sea level rise, hurricanes, and flooding. Climate change threatens urban land values as well as important historic landmarks and public resources such as hospitals. Heat tends to concentrate in dense urban centers, increasing health risks.

A worldwide investment of $3.2 trillion in energy conservation would pay for itself within 3 to 5 years, according to the U.N. Foundation. [34]

Challenge

To accommodate rapid urbanization and avoid the worst impacts of climate change, new buildings can be designed to meet zero-emission standards, and existing buildings can be retrofitted to greatly reduce their energy requirements. Areas of focus include accelerating reliance on renewable energy for heating and cooling and deploying resilient infrastructure designed to withstand the impacts of climate change.

40% of GHG reductions required by 2050 could be achieved through energy efficiency, according to the International Energy Agency. [35]

Innovation

Because such a large—and growing—percentage of the world’s population lives in cities, cities are an important place to innovate to reduce greenhouse gases. Several types of innovations offer promise [36]:

Energy demand-reducing innovations that increase the efficiency of existing buildings and new construction through improvements in lighting, insulation, heating and cooling systems, and building automation
Infrastructure resilience innovations that take into account the likelihood of flooding and other climate-related disruptions, including elevated roadways, urban swales, and other natural features that absorb excessive water, and protective barriers—along with novel finance models to support the investments needed to implement these improvements
Energy-sourcing innovations that allow for efficiently transitioning from fossil fuels to renewables to meet building heating, cooling, and lighting loads