How many cars are in the world?

According to a report from Ward's Auto, the number of cars worldwide reached approximately 1.015 billion as of 2010, notes Daniel Tencer for The Huffington Post. This number incited a lively debate on what the drastic increase in number of vehicles means for the world's economy and environment.

The United States has the largest population of cars by a large margin, with about 239 million cars, or 1.3 people per vehicle. China has the second largest number with 78 million vehicles, or 6.75 people per vehicle. It has the largest amount of growth, jumping 27.5 percent on an annual basis, and accounts for half the world's total growth in number of vehicles, notes Tencer.