In a famous ad, Apple asked people to "Think Different." We are now at a point in the natural history of the planet when it is essential to act different. There is no better time to begin than on Earth Day.
In 1970, the first Earth Day led to sweeping changes in public policy. It created a new constituency that demanded the Clean Air Act and the Clean Water Act to protect public health, and the Endangered Species Act to protect other living things.
In 2012, with the most polarized Congress in history, vital national legislation cannot even get a hearing. Consequently, the greatest immediate environmental opportunities today do not involve Washington, DC. They involve smart, sustainable choices by the private sector, states and cities, and individuals.
A good place to start is real estate.