This resource offers 3 different carbon footprint calculators. The individual calculator asks for car, transit, and home energy information based on your zip code. The calculator gives you the results instantly and then tells you what the trade off would be in terms of planting trees. For example, “Your carbon footprint is 5,784 lbs of CO2. That’s equivalent to planting 67 urban trees.” This is a great tool for an activity regarding individual carbon footprints. There are also business and event calculators.
Terrapass is a mission-driven business with a social goal to reduce the greatest amount of carbon emissions possible through education, online tools, carbon offsets, and renewable energy. They have received extensive recognition as the leading provider of carbon offsets in terms of quality and transparency.