Approximately one third of the world’s energy use takes place inside buildings. This has earned the building sector the dubious honor of being the Earth’s biggest contributor to greenhouse gas (GHG) emissions. What’s more, the construction industry consumes more than one third of the planet’s resources and generates huge quantities of solid waste. Clearly, any attempt to improve resource efficiency must take buildings into account.
If today’s building sector has an oversized ecological footprint, there is considerable hope for reducing it in the green future. Improving energy efficiency in buildings through greener construction methods and retrofitting existing structures can make an enormous difference in reducing GHG emissions. Moreover, many of these improvements can be realized at a low cost, using existing technologies. Green construction can also have a positive effect on productivity, public health, and even employment: according to estimates, every US $ 1 million invested could result in ten to fourteen jobs.
Cities are growing quickly, especially in developing countries. Urban areas are now home to some 50 percent of the planet’s population, use a good 60 percent of available energy, and account for an equal share of carbon emissions. Rapid urbanization is affecting water supplies, public health, environment, and quality of life, especially for the poor. Fundamental changes in urban development will have to take place in order to build a sustainable future.
Fortunately, the very density of cities may turn out to be their strongest advantage. Characterized by proximity, variety, and density, cities can be fertile ground for collaboration between local and national governments, civil society, private partnerships, and academia—all of whose input will be essential to the greening of our urban areas. With the right policies, practices, and infrastructures in place, cities can be green models for efficient transport, water treatment, construction, and resource use.
UNEP’s Sustainable Buildings and Climate Initiative (SBCI) is a partnership of major public and private stakeholders in the buildings sector working to promote sustainable building policies and practices worldwide.
Other UNEP work on buildings and cities includes the following projects: