Ozone Layer Depletion / CO₂ Emissions
One of the ongoing issues (and debates) in US environmental policy is the restriction of carbon dioxide emissions and their contribution to the depletion of the ozone layer. Many scientists contend that increased carbon dioxide emissions, associated with the use of fossil fuels such as coal and oil, are contributing to an increase in global climate temperature.

International agreements such as the Kyoto Protocol are targeted at reducing levels of the greenhouse gases. However the administration of George W. Bush rejected US participation in the Kyoto agreement in 2001, much to the disappointment of European allies (all of whom signed the agreement) and US environmental groups.

Suburban Sprawl
As new families formed after the return of American servicemen serving in World War II, they began to leave the overcrowded cities for the growing suburbs ringed them. The initial wave of suburban growth of the 1950's was exemplified by areas such a Levittown, Penn. (pictured right). The planned, cookie-cutter sameness of the Levittown houses offered quick, affordable housing to a growing American middle-class. The new construction of highways via the Eisenhower Federal Highway Bill offered the new suburbanites an eased commute into the urban business centers.

As suburban growth has continued seemingly unchecked for half a century, many have begun to question the impact these communities are having as they stretch further and further into the countryside. The associated issues surrounding continued suburban growth have been termed sprawl. The main issues focus on encroachment on wild lands, depleting water resources and the associated costs of extending power, sewage and municipal services to these more far-reaching, less densely populated regions. The city of Denver, Colorado serves as a classic example of the sprawl issues. Suburban growth around Denver has stretched into the outlying forested areas (making these areas susceptible to forest fires), water resources are stretched thin as new communities are built even amid tight regulations on water usage, and the associated costs of the new municipalities services have increased property tax rates for all of the greater Denver area.

Forest Fire and Wilderness Management
The first few years of the 21st century have seen some of the largest and most costly forest fires ever in the western states (Oregon, California, Arizona, Colorado). The resulting debate over forestry policy has been critical of past fire prevention efforts. For the greatest part of the past century forestry official (within the Department of the Agriculture) have actively worked to prevent and contain forest fires. Recently a policy of prescribed burns has been attempted, either setting or allowing controllable fires in an effort to thin fuel within the forests in order to make a larger wide-spread fire less likely. Logging restrictions and a ban on roads in federal forest lands have been criticized for contributing to the problems by allowing a build up of burnable materials. Compounding these issues has been the growth of suburban sprawl (see above) onto the edges of the once unoccupied forest lands, making these communities susceptible to fire damage and placing a greater demand on the forestry service to contain blazes. Future programs look to increase logging on federal lands and perhaps restrict the growth of communities along the edges susceptible forests.

Alternative Energy Resources
For much of American history we have been nearly entirely dependent upon fossil fuels (oil, gas, coal) for energy. However as use of fossil fuel resources have been proven to contribute to air pollution (ex. smog), acid rain and global warming (via depletion of the Earth's ozone layer), development of alternative energy sources has become a priority. Many also advocate energy sources as a way of reducing American reliance on imported oil.

The most commonly discussed alternative energy resources are those deemed to be renewable such as solar, wind and geothermal. Solar power (via the energy found in sunlight) has grown in Southwestern US and new windmill farms are slated for construction in New York State along the shores of Lake Ontario. Both of these resources are considered renewable due to the fact that no resource is used up in the power production process.

Other initiative as electric and hybrid automobiles (those running on traditional gasoline, supplemented with electric powered motors) and fuel cell technology (power cells that generate power by a chemical process that uses no fossil fuels) are being developed in order to curb fossil fuel use as well as reduce harmful emissions. States like California have lead these cleaner fuel initiatives, with programs such as the one that requires 10% of California cars sold be zero-emission (nonpolluting) by the year 2003.