Global Warming 101

Leonardo says that Americans make up 5 percent of the world's population, yet consume 25 percent of the world's energy and oil, making us the leading contributor of global warming emissions. He says that as concerned citizens, we need to take responsibility for the everyday actions that contribute to the problem—from the types of cars we drive to the way our energy is produced.

Dr. Oppenheimer agrees. He says that producing electricity by burning coal is the first largest contributor of global warming emissions. The next biggest chunk is from driving gasoline-fueled automobiles. In fact, cars are responsible for more than one-third of all greenhouse gas emissions.

It's estimated that Americans use more than 380 million gallons of gas every day. According to experts, if everybody bought the most fuel-efficient car available, the United States would save approximately 1.47 billion gallons of gasoline each year!

So what are the most fuel-efficient cars on the market today? Three hybrid cars: the Honda Insight, Honda Civic Hybrid, and Toyota Prius. What are some different options besides buying a hybrid car? Cars like the Ford Focus, Toyota Eco, or Chevy Aveo get great gas mileage and emit fewer emissions.