photo from here
ANA, a japanese airline is asking its passenger to go to restroom before boarding its planes. This is an abnormal request by All Nippon Airways, is part of its "e-Flight" promonation program to offset CO2. The program "e-Flight" also includes using recycled paper cups and plastic bottles instead of glass.
"This flight is a so-called 'eFlight.' The idea behind the operation is to think about the Earth in the sky above. Fuel reduction by lightening the weight of the aircraft will lead to restrain the carbon dioxide emission, which is one of the causes of global warming. Thank you for your understanding.", the airline announced before flying.
ref : cnn.com