Around a decade ago, the Japanese national airline....Nippon....started this short-lived effort to save on carbon emissions.
Their idea....while you were lining up to board the plane....they wanted you to go over to the bathroom, and try hard to discharge urine.
The idea was, with empty bladders....there would be lighter passengers onboard, and it'd save on fuel and carbon usage.
It was not exactly something that captivated the public. If you did the math and figured 250-odd people on the plane....maybe you'd save around 40 to 50 pounds of urine.
If you studied the concept, it would provoke other thoughts. Like for example....before you board a ferry....should you dump your load of pee? Or if you were on the ground-floor of a building....shouldn't you pee before entering an elevator?
What about city buses? Shouldn't you go behind the waiting point (into the bushes) and pee there....before boarding the bus, thus saving carbon there? What about the trip via your car to four grocery stops....shouldn't you pee before entering the car for each part of the trouble?
I figure in a 365-day 'year', if I aggressively peed when necessary....it might make a world of difference on fuel usage. I'd just call it....'peeing to save the world'.