Japanese Airline All Nippon Airways (ANA) is asking its passengers to use the restroom before take off in an effort to be more eco-friendly. ANA’s logic is that empty bladders lead to lighter passengers and lighter aircrafts, which allows the airline to use less fuel, cutting costs and helping the environment in one fell swoop. The experimental policy started on October 1 and will last for at least one month. If the strategy proves successful and is well-received by passengers, it could become permanent. ANA hopes to reduce its carbon emissions by five tons over this 30-day period.