What you can do

A beginner's guide to treading lightly

By EWEN CALLAWAY

Each morning Virginia Wilson spends about a half-hour biking to her job at Stanford.

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The ride gives her a chance to organize her day and get some exercise, but Wilson, an administrator in the planning office, says she also sees her commute as part of an effort to help the Earth. “I think we need to watch our carbon footprint,” says Wilson, referring to the amount of carbon dioxide gas a person generates.

Nearly everything we do produces carbon dioxide, the biggest contributor to human-influenced climate change. Driving a car, heating a home, even using a computer can deepen your carbon footprint. But with growing concern over the effects of climate change, many like Wilson have taken steps to reduce their burden on the planet.

Cool tips: Ways to reduce carbon emissions

  • Join an effort to push business and government leaders to address climate change.
  • Adjust the thermostat 2 degrees cooler in the winter and 2 degrees warmer in the summer.
  • Annual reduction in carbon emissions is about 2,000 pounds per household.
  • Unplug unused electronics — 1,000 pounds.
  • Air dry clothes — 700 pounds.
  • Wrap water heater in a $10 insulating jacket — 220-1,100 pounds.
  • Reduce garbage by half a trash bag per week through measures such as composting, recycling and avoiding excess packaging — 1,100 pounds.
  • Install energy-efficient compact fluorescent light bulbs on three frequently used lights — 300 pounds.
  • Plant shade trees and paint your house a light color in a warm climate or a dark color in a cold climate — 4,800 pounds.

For more information:

www.stopglobalwarming.org— More ways to reduce your carbon footprint

transportation.stanford.edu— Stanford commute calculator

www.eere.energy.gov/greenpower— U.S. Department of Energy list of utilities offering renewable energy

www.ucsusa.org— The Union of Concerned Scientists’ routes for taking personal and political action

Since the 19th century, humans have added huge amounts of carbon dioxide to the Earth’s atmosphere, increasing the levels of the greenhouse gas by a third. Most scientists agree that the extra carbon dioxide is already changing the climate. Increased temperatures have likely caused oceans to rise, glaciers to melt and hurricanes to intensify. According to the leading scientific authority on global warming, the Intergovernmental Panel on Climate Change, global temperatures in 2100 could be up to 11.5 F higher than in 2000. The hotter temperatures will cause more air pollution, reductions in water supply due to melting snowpack, and diminishing crop yields.

But there is hope, says Amy Luers, PhD, a climatologist with the Union of Concerned Scientists and former postdoctoral fellow at Stanford’s Freeman Spogli Institute for International Studies. “A lot of the most severe impacts can be avoided through reduction of greenhouse gases.”

Stanford social worker Jane Rothstein takes the same attitude with carbon reduction as she does with other health interventions, such as improving diet or reducing stress. In addition to leading classes on stress management and nutrition, she teaches people how to live greener. “It’s a matter of learning to do it in a patient, gradual way,” says Rothstein.

But where to start? “At least 40 percent of our carbon dioxide output in California is from automobiles,” says Rothstein. Each gallon of gasoline a car burns puts pounds of carbon dioxide into the atmosphere, and the average car emits 12,000 pounds per year. The Stanford transportation office has a Web-based calculator that estimates how much carbon and money you can save by driving less. Changing the air filter in your car (saving 800 pounds per year) and keeping your tires inflated (saving up to 250 pounds per year) also help.

Energy use at home is a large part of the carbon footprint, and efficient energy use can make a difference. Another option for some is choosing carbon-free energy. Many utility companies offer energy from carbon-free sources to customers willing to pay a (usually small) premium.

To keep global temperatures from rising more than 4 degrees F by 2100, the United States must limit its carbon emissions to 92 billion tons during the entire 21st century. Averaged out, that gives each U.S. resident an allowance of just three tons of carbon per year — compared with the 23 tons the average resident now produces. And unfortunately, right now carbon emissions are rising, not falling. It’s time to reverse the trend.

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