Image from the Rainforest AllianceEver since I saw An Inconvenient Truth, I've been a bit obsessed with the amount of damage that I am personally inflicting upon the environment. In the movie, Al Gore quantified the impact of reducing CO2 emissions so deftly that I've wished for a little gadget to monitor the exact size of my carbon footprint on a daily basis. Nothing feeds my obsessions like cold, hard data.

A little surfing led me to several carbon footprint calculators, which determine the exact amount of emissions we're responsible for each year. My favorite turned out to be one that I found one via the New York Times called the Carbon Zero Calculator created by The Conservation Fund.

It turns out that I am personally responsible for about 31 tons of CO2 emissions per year. To offset one year of damage will take no less than 23 trees and a period of 70 years. To undo 70 years of damage will apparently require a full-blown forest consisting of about 1,600 trees.

To reverse all the havoc that I wreak, I can donate $125 to the Fund -- the amount that apparently absolves me of my crimes against nature. That's the cost to plant 23 trees, which works out to a very reasonable $5.21 per tree. Obviously, it's a bargain, but I immediately found myself trying to get a better deal.

I rationalize that since I planted four trees (well, actually more like three trees and one really big shrub) earlier this year as part of a landscaping project, it'll take approximately 19 trees to clear my conscience. This simultaneously buys me a guilt-free existence and saves me about $20.

Call it creative math, but I welcome a discount when it comes to settling my tab with the universe.