Cities

Housing and automobiles in the United States generate almost 40% of the nation’s carbon dioxide emissions. Emissions vary with an area’s population density and weather patterns.  These in turn affect automotive and transit use, home heating, air conditioning and electricity usage.

Plastic trash is a potential — and plentiful — fuel source, but up to the present many regions of the United States have been reluctant to adopt waste-to-energy technologies. Among the reasons are the availability of relatively cheap land for trash disposal, recyclers who viewed such programs as potential threats, and resistance by local homeowners.

Train and subway stations play a significant role in both transit networks and the urban environment. While numerous studies have examined stations’ effect on property values, the results have been mixed: Some show a negative impact, others insignificant differences, and some indicate positive effects.

More than half the world’s population now lives in urban settings, and by 2050 the percentage is expected to rise to 70%. Because cities will be home to so many, it’s essential to better understand the health benefits and risks of urban living.

Automotive transportation, one of the largest sectors of the U.S. economy, has numerous societal benefits but also many downsides — pollution, fatalities, congestion. Getting the price individuals pay for driving to reflect its true cost to society is one of the most significant challenges of public policy.

Once part of the urban fabric of the United States, streetcars declined as the automobile rose during the 1930s and 1940s. In the last several decades, however, streetcars have returned to popularity — more than 40 new systems are in planning, construction or operation.

In the quest for increased energy efficiency and smaller carbon footprints, many individuals are now making more conscious consumer choices, looking for greener alternatives in everything from household appliances to hybrid vehicles. However, the basic structure of homes, as well as the areas in which they were built, may represent deep challenges to achieving real cuts in personal and family energy consumption.