You recycle. You take public transportation to work. You even gave away your air conditioner. Before you gloat over your low-carbon lifestyle, however, make sure your choices really are making a difference. Tally up your impact on global warming using a carbon calculator.
These online programs tabulate your personal annual carbon emissions when you enter data such as your heating bill, recycling efforts, miles flown per year, and eating habits. They crunch the numbers using national stats and the latest scientific research. Algorithms are run. Out pops the number of tons of CO2 you produce annually—your carbon footprint.
There are a variety of calculators out there, measuring everything from the energy it takes to make, operate, and dispose of a single appliance, to how much carbon you create while at work. Some calculators measure carbon as well as other factors to determine your ecological footprint–the number of global acres your lifestyle uses–or how many planets it would take to sustain earth’s population if we all could live like you.
We’ve assembled a variety of the best sites below. Remember, every calculator weighs lifestyle choices differently, and no one calculator can analyze all possible variables—thus you’ll get a range of results from different calculators. Still, nothing gives you pause like a pie chart showing that you churn out more carbon in a year than Chad. The country.
The dashboard-style design of Conservation International’s calculator is a cinch to navigate and includes options for simple or detailed calculations. The quiz is divided into household, driving, and travel sections. Each time you enter data, your carbon load is adjusted real-time.
Cool feature: Choose to calculate your personal annual footprint or the carbon you’ve used for a specific event or a trip.
Not so hot: It doesn’t account for your use of public transportation, your eating organic produce, or measures you’ve taken at home to use fewer resources, such as recycling and installing low-flow showerheads.
The Nature Conservancy’s efficient calculator, which can be found by clicking the link at the bottom of its website’s homepage, has questions grouped by home energy use, driving and flying, food and diet, and recycling and waste. It asks—and explains why it asks—about seemingly benign habits like composting and checking your car’s tire pressure.
Cool feature: As you answer each question, color-coded bar graphs reflect your results and compare them with national averages.
Not so hot: Many questions are qualitative instead of quantitative; For example, one asks how well you’ve tried to heat and cool your home efficiently, instead of tabulating your actual heating and cooling bills.
The Inconvenient Truth site offers a quick and simple way to estimate your annual personal CO2 emissions from transportation and home energy use—the two areas that account for most individual CO2 pollutants. It considers the location and size of your home and your monthly payments for electricity, heat, and gas.
Cool feature: It factors in the percentage of energy you use that is