Here's how to cut CO2 emissions: make it very costly for corporations to force people to come to offices every day. If we slashed commuting for all white-collar workers worldwide it's estimated we'd save at least 9 million barrels of oil per day (some estimates of savings are nearly twice this) - enormously more than all the airplane flights in the world. But as we never see the big picture, we'll waste billions attempting to do stupid things like build electric aircraft, while still making people waste millions of hours per day commuting to energy-inefficient offices. It's important to remember the concept of "personal carbon footprint" was originally promulgated by the fossil fuel industry as a deflection. It's not a meaningful concept, but it's a great soundbite.