Counting the Family Carbon - NYTimes.com Which has the lower carbon footprint - our life in the New Jersey suburbs or our life in a cabin in the woods of Maine? We recently hit the halfway mark for our year in the woods, so I now have enough data to answer the question. As a social scientist at the Nature Conservancy, I collect data compulsively. It's not my only compulsion, but it's on par with drinking fine beers. Sadly, the two do not mix well - unless I'm counting beers. Since we moved from Australia to New Jersey nearly six years ago, I've carefully collected data on how many miles we drive each year, how much household electricity and natural gas we use each month and how far we travel by air. In Maine, I collect data on miles driven, firewood consumption, diesel fuel used for our backup generator, propane for the stove, water heater and back-up heaters, and the air miles flown when one of us travels for work or pleasure. To convert the data to carbon dioxide emissions is tedious, so I looked at online carbon footprint calculators. A number of them are aimed at fund-raising and education and end with a "suggested contribution" and banal advice like urging you to switch to compact florescent lights, while not providing much in the way of actual data crunching. I needed a calculator that could use my data with a greater degree of precision. The best carbon calculator I found is at www.carbonfootprint.com. It allowed me to enter multiple fuel sources and even the type of car we drive by model and year. Inputting firewood was not possible, but there was a place for "wood pellets" so I converted a cord of our firewood to the wood-pellet equivalent based on B.T.U."s. B.T.W., one ton of wood pellets equals 66 percent of a cord of beech. So how does our carbon footprint living in a New Jersey suburb compare with that of living in a cabin in the woods of Maine? The first surprise was that our carbon emissions in Maine are three times higher than our emissions at home in New Jersey. In Maine this year, we are on track to generate 17 metric tons of carbon per person (85 tons for the family) - close to the United States per-capita average of 20 tons per year. In New Jersey, we generated an average of 5 tons a year per person. Several studies have examined urban and rural per-capita carbon emissions, and we are not that unusual. Urbanites tend to have smaller carbon footprints than people in rural areas. The major difference is transportation. In New Jersey, we drove an average of 8,051 miles a year over the last five years. In Maine, we drove 10,162 miles from July to December, and we are likely to drive about 20,000 miles in our year in the woods over all (excluding the New Jersey-to-Maine miles). In Maine, we are 5 miles from the post office and 19 miles from the grocery store. In New Jersey, the mail is delivered and we can walk to the grocery store. Even though we heat with wood in Maine, which has a minimal carbon footprint, and much of our electricity comes from solar, the difference is not enough to offset the extra miles driven. About 66 percent of our Maine carbon footprint comes from cars. A gallon of gasoline weighs 6.3 pounds, but when it is burned, it produces 20 pounds of carbon dioxide. The third surprise was how much carbon dioxide our family of five generates regardless of where we live. Carbon emissions are measured in carbon dioxide-equivalent metric tons, and one metric ton equals 2,204 pounds. Even living a carbon-thoughtful life, we generate a minimum of 24.6 metric tons or 54,234 pounds. Every year. That's a lot of carbon. The third surprise was that we could drop to two metric tons per person in New Jersey - the worldwide target to combat climate change - if we lived just as we did before but with two changes: adding solar panels to our roof and driving a hybrid. It's doable and would not negatively impact our quality of life. From a climate change perspective, we are better off living in an urban area or a suburban area with decent mass transit. But carbon is only part of the story. Our rural Maine life is in many ways more environmentally sustainable than our suburban New Jersey life. In Maine, we're solar-powered and wood-heated and buy local food whenever possible. It's a modern version of an old life that is very much sustainable. In New Jersey, not even the grass on our lawn is environmentally sustainable. Carbon dioxide emissions matter greatly, but lowering them to a sustainable level is only one step toward living a life that, as a landmark 1987 report put it, "meets the needs of the present without compromising the ability of future generations to meet their own needs."