Automobile travel is a significant contributor to CO2 emissions ? especially when you consider the sheer volume of cars; however, when comparing the effects of an auto to those of other forms of transportation it sometimes become the most efficient mode - especially when you load that Prius with four people.

Remember - when you travel you have choices in rentals - check with your agency
How we calculate CO2 emissions from your car
WWe use the the year, make and model of your car to calculate the CO2 emissions for your trip. Alternatively, you can just enter the MPG from your particular vehicle. From that we use a simple formula to determine your CO2 emissions for that trip depending on whether you have gas or diesel power.