we have to go and started telecommuting and not always traveling and when i wrote the book with dan spurling, i think the -- we got together in five years of the writing it three times and had a virtual experience writing the book so there wasn't a lot of miles or oil or car trips or airplane trips in the book and i think that is the type of productivity we'll have to think more about. >> what about when it comes to transport and actually moving people? what is this solution. >> the solution is probably choice. right now, we have no choice. if you want to go somewhere you came here and you drove, presumably and if you want to go somewhere, 95% of the time you are driving. and, 98% of the energy moving you in that car is oil so we have no choice in vehicles and no choicen fuels. and that is the biggest problem, we have to really start thinking about different types of cars that are more fuel efficient using different types of fuels like electricity and cellulosic biofuels and then, having different types of mobility options so it's not always a car you have to pick. if you are old or young, o