Does Peeing Before Boarding an Airplane Really Save Carbon Emissions?

Airport Bathroom Image

Image Source: Specialkrb
Dear Pablo: Can Airlines really save fuel by asking their passengers to empty their bladders before boarding?

Although their website makes no mention of it, Japan's All Nippon Airways (ANA) has been widely reported to be trying an experiment for the month of October: they are asking their passengers to "lighten the load" by visiting the restroom before boarding.An article by the UK's Daily Mail estimates that the average weight saved per flight is just over 60 kg (or as one reader commented: Assuming a take-off weight of 140,000 lbs and 160 passengers (a Boeing 737), the weight saved would amount to .11% of the takeoff weight). During the one month-long trial period, and over 42 flights, the weight savings will add up to over 2600 kg and will save an estimated five metric tons of greenhouse gas emissions (maybe more if the take into account the Radiative Forcing Index).

Silly Stunt or Legitimate Emission Reduction Effort?

Is this just a silly stunt to get attention in the media, including from this writer, or is it a legitimate attempt to reduce greenhouse gas emissions? Well, with the urgency of addressing climate change, every little emission reduction counts. But is there more effective "low-hanging fruit" to be tackled by the airline industry first? One commenter to the Daily Mail article pointed out that, just by reducing the amount of fuel carried by 50 gallons, it would save the airline more weight, and greenhouse gas emissions than asking everyone to go pee first. The problem with this is that pilots are already being forced to fly with seriously low fuel levels, dramatically increasing the number of low-fuel emergency landings. So maybe that isn't the best idea.

How Else Can Airlines Cut Emissions?

But there are some opportunities to cut weight and fuel use that are being explored. Switching to LED lighting and other, more energy efficient technologies aboard the airplane can reduce fuel use. It has also been shown that flushing the lavatory toilet requires 1 liter of fuel, so why not install lavatory-sized waterless urinals? Also, Lufthansa has for years shifted its in-flight snack services on regional flights to the airport waiting area. This allows the airlines to carry only what passengers actually intend to consume.

What Is The Rest Of The Airline Industry Up To?

How any of these initiatives will play into the new emissions reduction goals of the airline industry is not yet known but they will have to come up with some innovative solutions in order to meet them. The International Civil Aviation Organization (ICAO) has recently come up with the following goals:
  • Improving fuel efficiency by an average of 1.5% annually to 2020
  • Stabilizing emissions from 2020 with carbon-neutral growth
  • A 50% net reduction in carbon emissions by 2050 compared to 2005

The Greatest Irony About It All

What is ironic is that the airline that is saving 5 tons of greenhouse gas emissions in October by asking its passengers to pee before boarding is creating many more greenhouse gas emissions through their newly announced helicopter airport transfer for First Class passengers. Helicopters, of course, are one of the least efficient means of transportation from an environmental perspective.
Pablo Päster is a weekly columnist for, an experienced greenhouse gas engineer and the Senior Environmental Program Manager at Hara Software. Send your questions to Pablo(at) and connect to his RSS feed.

Additional Resources on Air Travel:
Air Travel and Climate Change: Take the Train
Air Travel TreeHugger Style
Nature Air - The World's Only Zero Emission Airline?
Does Peeing Before Boarding an Airplane Really Save Carbon Emissions?
Although their website makes no mention of it, Japan's All Nippon Airways (ANA) has been widely reported to be trying

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