• percentage of the Earth’s surface covered by cities

• percentage of the Earth’s surface covered by rainforests

• number of miles of highway laid down in Florida each day

• percent by which global energy use is projected to increase annually over the next 15 years

• factor by which an average home generates more greenhouse-gas pollution than an average car

• percent by which use of oil grew each year between 1990 and 1998

• factor by which the volume of oil transported throughout the world has grown since 1981

• number of hours a jet ski engine must operate to produce as much air pollution as a 1998 car driven for 130,000 miles

• number of weeks worth of thrown-away glass bottles and jars that it would take to fill both of New York City’s 1,350-foot-tall Twin Towers

1 — Worldwatch Institute
2 — Natural Resources Defense Council
3 — National Wildlife Federation
4 — World Resources Institute
5 — Alliance to Save Energy
6, 7 — Worldwatch Institute
8 — California Air Resources Board
9 — Environmental Defense Fund