How many trees does it take to absorb the emissions from your car's commute? How much land does it take to feed and raise the beef you eat for dinner? How much space on earth does your trash take up?
The city of Santa Monica has taken up the task of answering those questions in "Santa Monica's Ecological Footprint, 1990-2000," released in March. The report measures the amount of land used to produce everyday products and services like electricity, transportation, garbage disposal and housing. That land use is called the ecological footprint, and it can be measured individually or citywide.