Environment / Pollution

Image courtesy of Salem Krieger/Veer

Two and one-tenth pounds of carbon dioxide. That is our best estimate of what is emitted into the atmosphere when we harvest trees, turn the freshly milled paper into your individual copy of DISCOVER, get it into your hands, and see it to its final resting place. For comparison, this is the same amount of CO₂ produced by twelve 100-watt lightbulbs glowing for an hour or a car engine burning 14 ounces of gasoline.

As a publication that keeps a close eye on the state of the planet, DISCOVER decided it was time to look in the mirror and take stock of our own contribution to the greenhouse-gas problem. That means accounting for greenhouse-gas emissions due to all the processes from harvesting, milling, and printing to shipping, recycling, and stowing in landfills: looking at every step of the magazine’s life cycle.

To define the scope of our analysis and set the standards for our calculations, we turned to the Greenhouse Gas Protocol, a widely used emissions accounting tool for businesses and governments. (It was created by the World Resources Institute and the World Business Council for Sustainable Development, a coalition that gathers information on how to make businesses greener.) We then got cracking on the numbers, with an immediate objective in mind: to buy carbon dioxide offsets to make this issue carbon neutral.

From the Office
Before an issue of DISCOVER can exist as a physical object, it needs to be conceptualized, reported, written, edited, fact-checked, copyedited, designed, and supplemented with advertisements. That requires 35 people to make their way to our New York offices every workday. We surveyed all our staff (see “Personal Mark,” below, for a breakdown of two staff members’ out-of-office footprints) for commuting mileage, mode of transportation, business travel, and messenger trips needed to do their jobs. From there we used government emissions estimates for subways, buses, cars, and air travel to determine that DISCOVER’s staff puts out 5.4 tons of carbon dioxide getting around each month.

Then there’s the office itself. Heat and air-conditioning keep it habitable throughout the year. Its energy-using devices—computers, fluorescent lights, printers, and (of course) the fridge and coffeemaker—allow us to do our work. We looked up a month’s electricity and natural gas usage for the entire building where we lease our offices and estimated our respective portions to be 9,091 kilowatt-hours (the average single-family home uses 1,000 kilowatt-hours per month) and 589 therms, the equivalent of burning about 58,900 cubic feet of natural gas. Using emission rates from the EPA for electricity generation in our region and natural gas emission figures from the Department of Energy, we determined that our office’s energy use adds another 8.7 tons of CO₂ to the total.

To the Northern Forests
Once the magazine is ready for printing, we notify our paper supplier, who has paper shipped from a mill in Quebec to our printing plant in Jonesboro, Arkansas. It is a behemoth shipment: Printing a million or so copies of DISCOVER every month takes over 348,000 pounds of paper, according to Bill Branch of Quebecor World, which handles our printing and distribution. The shipment makes the 1,450-mile journey by truck in some months and by train in others. We split the difference, assuming that it travels half the time by road and half by rail. Using greenhouse-gas figures for truck and rail from the Greenhouse Gas Protocol (and assuming tractor trailers running at six miles per gallon of gasoline), we found that moving this monthly 174-ton load kicks out 13.7 tons of CO₂ .

Making paper is an emission-intensive process on its own. Each magazine begins as a tree in the forests of Quebec (fir, spruce, or pine), which is harvested and transported to a sawmill. Chips and sawdust from here make their way by boat to a paper mill (pdf) in Quebec, where the wood fibers are separated, creating pulp, and bleached white. Water is mixed with the pulp to form a slurry, which is then spread into a thin sheet, pressed to squeeze out the liquid, and dried.

To calculate the impact of these processes, we consulted the results of the Paper Task Force, a joint project of the nonprofit group Environmental Defense, Duke University, and several large corporations. Part of their work details the CO₂ emissions per ton of paper for a variety of different products, including the lightweight coated stock used for magazines. The quantity of that paper DISCOVER uses every month releases 614 tons of carbon dioxide—making it the single largest source of emissions in the production chain. Even so, this takes into account only the manufacturing process. Harvesting and transporting the trees to the mill bumps up the CO₂ count another 22 tons. Add the magazine inserts (those little cards that offer subscriptions)—which amount to 8 tons of 50-percent-recycled content—and we gain another 20 tons.

From the Mill to the Presses
At the printing plant, the footprint continues to grow. By looking at the plant’s total annual utility use and the fraction of yearly operations needed to print a single issue of DISCOVER, David Hakenewerth, a manager at Quebecor’s Jonesboro facility, determined that producing one month’s edition of the magazine consumes 63,364 kilowatt-hours of electricity and 1,704 therms of natural gas. According to government carbon dioxide emission rates for the region’s electricity and fuel, these processes account for another 52 tons of CO₂ . But this does not include the ink, a product whose footprint is not nearly as well studied as paper. Evaluations of two other printed products came up with the same emissions estimate. Ink accounted for about 1 percent of the total greenhouse-gas emissions for both products. Assuming the same holds true for DISCOVER, ink would bring an additional 9.6 tons of CO₂ to the emissions calculation.