The eco footprint concept is an interesting one. It is an index that measures how much an entity (e.g. country, city, person) consumes, and then assumes that if everyone in the world consumes at the same rate, N-number of planets would be needed to support life on earth. Obviously... we only have one planet... so the implication is pretty clear!
Personal Footprint Quiz -- I scored 22* (typical American: 24) -- this level requires 5 planets.
* 22 acre (hectare) of biologically productive space with world-average productivity [FAQ]
It brought me to a "Take Action" page that breaks down what actions can be taken and re-calculates my footprint. E.g. if I...
- Shorten my shower by 10 minutes, reduce my clothes dryer load by 30%, convert 25 CFL lightbulbs, reduce my thermostat by 4 F (I ilke it extra warm at 72F), use central heating 5 instead of 6 months per year (ok, I like it REALLY warm... I came from the tropics), my score goes down by 1 (acre).
- Reducing my driving by 20 miles/week saves 0.3 (acre)
That's not bad... these are the habits I can change fairly easily, within the next 2 months. I picked only lowest hanging fruits from all the items in the list. We can all do that... pick the easiest change that makes a difference.