National Geographic : 2009 Mar
desktop calculator, laptop computer, printer, clock radio, cable TV box, camera battery recharger, carbon monoxide detector, cordless phone base, smoke detector. What were they all doing? A study by the Lawrence Berkeley National Laboratory found that "vampire" power sucked up by electronics in standby mode can add up to 8 percent of a house s electric bill. What else had I missed? "You can go nuts thinking about everything in your house that uses power," said Jennifer orne Amann, author of Consumer Guide to Home Energy Savings, who had agreed to be our group s energy coach. "You have to use common sense and prioritize. Don t agonize too much. Think about what you ll be able to sustain a er the experiment is over. If you have trou- ble reaching your goal in one area, remember there s always something else you can do." AT THIS POINT WE LEFT HOME for a long weekend to attend the wedding of my niece, Alyssa, in Oregon. While we were gone, the house sitter caring for our two dogs continued to read our gas and electric meters, and we kept track of the mileage on our rental car as we drove from Portland to the Paci c coast. I knew this trip wasn t going to help our carbon diet any. But what was more important, a er all, reducing CO emissions or sharing a family celebration? at s the big question. How signi cant are personal e orts to cut back? Do our actions add up to anything meaningful, or are we just mak- ing ourselves feel better? I still wasn t sure. As soon as we returned home to Virginia, I started digging up more numbers. e United States, I learned, produces a h of the world s CO emissions, about six billion metric tons a year. That staggering amount could reach seven billion by 2030, as our pop- ulation and economy continue to grow. Most of the CO comes from energy consumed by buildings, vehicles, and industries. How much CO could be avoided, I started to wonder, if we all tightened our belts? What would happen if the whole country went on a carbon diet? Buildings, not cars, produce the most CO 0.3 PASSENGER & FREIGHT RAIL 8.9 MILLION BARRELS OF PETROLEUM USED PER DAY IN 2006 4.9 CARS 4.0 LIGHT TRUCKS 2.5 MEDIUM & HEAVY TRUCKS 1.2 AIRPLANES 0.7 SHIPS & BOATS TRANSPORTATION TOLLS CO AMOUNTS MEASURED IN METRIC TONS SEAN MCNAUGHTON, NG STAFF SOURCES: ENERGY INFORMATION ADMINISTRATION, ANNUAL ENERGY OUTLOOK 2008; DEPARTMENT OF ENERGY, TRANSPORTATION ENERGY DATA BOOK, EDITION 27 Left: Today's internal combustion engines are inefficient at converting fuel to motion. Cars waste up to 85 percent of the energy from the fuel in their tanks, losing a big chunk as heat. Cars and light trucks consume the lion's share of petroleum used for transportation in the U.S. Modest changes in efficiency and driving habits could add up to significant fuel savings. If we drove our cars 20 fewer miles each week, we could reduce their CO2 emissions by 107 million tons each year, a 9 percent decrease. If we improved our cars' gas mileage by 5 miles a gallon, we could cut their CO2 emissions by 239 million tons each year, a 20 percent decrease.