* Miles driven: This is the biggest factor. A car driven 10,000 miles a year will produce far less CO2 than one driven 25,000 miles a year.
* Fuel efficiency: Cars with better gas mileage (miles per gallon or MPG) produce less CO2 per mile driven. A hybrid or electric vehicle will produce significantly less than a gas-guzzling SUV.
* Type of fuel: Gasoline produces more CO2 than some alternative fuels (though the CO2 emissions associated with the production and transportation of the fuel must also be considered).
* Driving style: Aggressive driving reduces fuel efficiency and increases emissions.
* Vehicle maintenance: Properly maintained vehicles tend to be more fuel-efficient.
There's no single answer. However, a rough estimate for a gasoline-powered car in the US driven an average of 15,000 miles per year might be in the range of 4 to 6 metric tons of CO2. This is a very broad range, and the actual amount could be significantly higher or lower depending on the factors listed above. A fuel-efficient car driven less would be at the lower end, while a large SUV driven extensively would be at the higher end or beyond.
To get a more precise estimate for a specific car, you can use online CO2 emission calculators. These calculators typically require you to input the car's make, model, year, and annual mileage. The EPA's website (epa.gov) is a good resource for this type of information, as are many other websites dedicated to fuel efficiency and carbon footprint calculations.
