Which Is Greener: Flying Or Driving To Your Destination?

Few transport methods are truly green, requiring the input of fuel at some point in the process to generate the energy required to move.
Flying is often derided as one of the worst, given the spectacular amounts of fuel aircraft can burn through. But are they any worse than cars? Indeed, could they be better for those cross-country trips?
The University of Michigan's Transport Research Institute has drawn up a report looking into exactly this scenario, and has come up with a surprising conclusion--for the most part, it's greener to fly than drive.
In fact, for cars to be a more efficient means of moving people about, average fuel economy of light-duty vehicles would have to increase by around 50 percent, or average passenger numbers would need to double.
In the report, Making Driving Less Energy Intensive Than Flying, author Michael Sivak analyzes the amount of energy needed to transport a person in the U.S. a given distance, either in a light-duty vehicle or on a scheduled airline flight.
While automobiles have generally become more efficient over the decades, the airline industry has leapfrogged road transport as the greenest way of moving people about.
Popular Mechanics cites a table in the report showing the energy intensities of flying between 1970 and 2010.
Back in 1970, airline travel used twice the energy per passenger to move people about. But by 2000, energy use per passenger had decreased below that of driving, and today it's 57 percent less energy-intensive.
To restore the balance, according to the report, the current fuel economy of the entire fleet of light-duty vehicles would have to increase from 21.5 mpg to 33.8 mpg, or average passenger numbers would have to increase from 1.38 persons to at least 2.3.

                                                                                             Full article Here