A little surfing led me to several carbon footprint calculators [1], 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 [2] called the Carbon Zero Calculator [3] created by The Conservation Fund [4].
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.