50 3.5 3.9 4.4 5.0 5.9 7. 1 8.8 11.8 45 40 35 30 25 20 15 Reduce your greenhouse gas emissions by choosing a car with better gas mileage. MPG A n n u a l T o n so fG H G At Sunny Middle School, Ms. Addison’s class is investigating how greenhouse gases (GHGs) contribute to global climate change. They wrote their research on note cards: • Greenhouse gases cause climate change by trapping heat on the planet. • Greenhouse gases contribute to smog and air pollution, which can cause respiratory diseases, like asthma. • Extreme weather, disruptions to the food supply, and increased wildfires are also caused by greenhouse gases. “Where do greenhouse gases come from?” Mia asked. “One of the most common greenhouse gases is carbon dioxide, also known as CO2. People release CO2 into the atmosphere when we burn fossil fuels (like coal and natural gas) for energy and transportation,” Ms. Addison answered. The class examined the graph to the right. The source for the largest percentage of CO2 emissions for a typical household was vehicles. The students conducted some research and found: > Highway vehicles release about 1.7 billion tons of GHGs each year. > Each gallon of gasoline burned creates 20 pounds of GHG. > A typical vehicle releases 6 to 9 tons of GHG into the atmosphere each year. For their group project, Mia and Ichiro researched hybrid cars that combine gas and an electric motor. “Awesome, so it consumes less fuel and emits less CO2 into the environment,” Ichiro said. “While hybrid cars are better for the environment, I’m seeing that some people are hesitant to buy one because of the higher purchase price,” Mia noted. They found the graph to the right, which shows the miles per gallon (MPG) and the annual tons of GHG produced by 8 different types of cars. If each gallon of gasoline burned created 20 pounds of GHG, and the price of gasoline was $2.454 per gallon, how much money was saved annually on gas by the car that got 40 miles per gallon when compared to the car that got 20 miles per gallon? Provide your answer to the hundredths place. Note: 1 ton = 2,000 pounds
