The International Civil Aviation Organization has developed yet another tool for calculating your carbon footprint. The ICAO Carbon Emissions Calculator allows you to estimate how much carbon is spewed into the air thanks to your air travel. For instance, my family and I are traveling to Milwaukee, Wisconsin this weekend for a friend's wedding. Four passengers flying from Denver to Milwaukee in economy will generate about 655.15 kg (or 407 miles). (I admit I feel guilty.) Nothing works as well as reducing travel or energy usage altogether, but at least I'll be able to easily offset my travel using Live Neutral, TerraPass, or Carbon Fund.