4.54 Billion Years
Provider: Women's Health
In the past century, the planet's average temperature has risen from 57°F to 58.3°F. That's like a human's running a constant fever of 99.9. A recent report from the United Nations Intergovernmental Panel on Climate Change, the group of 3,750 climate scientists who won the Nobel Peace Prize in 2007, predicts that the temperature will rise an additional 3.2 to 7.2 degrees by the year 2100, largely because of carbon dioxide emissions. On the low end, that's like your having a 103-degree fever.
Adjusting your home thermostat by just three degrees—a bit cooler in the winter and a bit warmer in the summer—can reduce CO2 emissions by half a ton per year. A programmable thermostat (look for one with the Energy Star label) reduces emissions even more by automatically adjusting the temp while you're asleep or away.
Mother Earth is breathing in a lot of secondhand pollution. The concentration of CO2 in the atmosphere has increased, from about 280 parts per million (ppm) in pre-industrial times to 383 ppm in 2007, mostly as a result of our burning fossil fuels such as coal, oil, and natural gas. Without changes in the way we generate electricity, power cars, and heat homes, scientists predict, CO2 levels will reach at least 550 ppm by 2100.
The average American generates 7.5 tons of CO2 annually. Figure out your share with an online carbon calculator
, then strive this year to reduce your contribution by 10 percent—more if you can. An easy start: Keep your tires properly inflated. That will instantly improve gas mileage by 3.3 percent, and every gallon of gas you don't use is about 20 pounds of CO2 out of the air.
In the past few years, the speed at which the Arctic ice sheet is melting has increased at an alarming rate. It is believed to be half the size it was in the 1950s, and many scientists think the Arctic could see its first ice-free summer as soon as 2030. Like an enormous ice cube melting in a glass of water, sea-ice melt doesn't directly affect global ocean levels. It does, however, make the water at the top of the world warmer. This can cause land-based ice masses to thaw—and when that water runs into the ocean, sea levels rise. The melting of Greenland's ice cap, Antarctic glaciers, and other land-based ice has already contributed to the 6.7-inch global sea-level rise on record for the 20th century. The IPCC predicts that if fossil-fuel use continues as projected, sea levels will rise another two feet by 2100.
Adopt a penguin. Your $50 donation to the nonprofit Defenders of Wildlife (changingthepresent.org
) will actually help the Washington, D.C.-based group lobby for higher fuel-efficiency standards and the development of alternative fuels for vehicles. (Cars and trucks are responsible for nearly a quarter of Americans' greenhouse gas emissions.)
The earth supports at least 1.5 million species. But the planet's biodiversity is decreasing. In the oceans, an estimated 90 percent of large fish have disappeared since the 1950s. In the African and Asian forests, 114 of the world's 394 primate species are threatened with extinction. In the United States, we've seen bird numbers decline and honeybee populations collapse. A recent UN report found that current biodiversity changes are the fastest in human history. In fact, of the vertebrate species that have been well studied, 23 percent of mammals, 12 percent of birds, and more than 30 percent of amphibians are endangered.
Humans have a strong track record of pulling endangered species back from the brink—just look at the bald eagle. Join the effort by supporting the World Wildlife Fund (wwf.org
) or Conservation International (conservation.org
), where your donation helps protect disappearing bee habitats (and your food supply—the little stingers pollinate about a third of all the fruits and vegetables you eat).