There is no cut-and-dry answer to this question. The answer depends on everything from the type of vehicle or plane to the number of passengers and distance traveled. Ultimately, emissions from jets include not just carbon but other pollutants as well. In many cases, the environmental impact can be more significant for flights than for car trips. According to the International Council on Clean Transportation (ICCT), driving tends to be better for the environment when compared to flight on a passenger miles per gallon (PMPG) basis.