The truth behind airline cabin rubbish and where it ends up
The confines of a plane cabin can often be compared to a rubbish tip as passengers exit after a long-haul flight.
According to the International Air Transport Association (IATA), passengers generated 5.2 million tonnes of waste in 2016. That is roughly an equivalent to 43,000 Boeing 787 Dreamliners, and IATA warns this figure could double within 15 years if the process of dealing with rubbish doesn't change.
The aviation industry spends an estimated US$500 million (NZ$690 million) on cabin waste costs annually. Barely anything is recycled as cabin rubbish is gathered up to be incinerated or buried.
Amongst the leftover meals, crumpled newspapers and discarded cups, unused blankets and headphones are also typically treated as trash.
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"It's disgraceful," said Matt Rance, CEO of MNH Sustainable Cabin Service.
MNH produces reusable blankets and headphones that can be used up to five or six times for airlines such as Emirates, Qantas and Etihad.
At the end of a long-haul flight, MNH collect the items, services them, and sends them back to the airline. Once the products have reached the end of their life, Rance said old blankets are sent to homeless or relief charities, while headset sponges have "weird and wonderful" uses such as lining the floor of equestrian centres to protect horses' hooves.
While Rance concedes changing the habits of airlines is challenging, he's praised the "progressive" carries for coming on board. Cathy Pacific and Qantas have both said they are working alongside companies on redistributing uneaten inflight meals to those in need.
Rance said that his company has a "lonely existence" in the aviation industry, but added that others are trying to do their bit.
OzHarvest at Brisbane Airport distributes uneaten plane meals to the homeless, while Gatwick Airport opened an on-site biomass plant to convert waste into energy.
So why has the industry not opened up to these new initiatives?
"Many countries have very strict regulations on food [or food-contaminated waste] being brought in," said IATA's Chris Goater. "They take a precautionary approach and often it has to be dealt with very strictly." In other words, waste is burnt or buried.
"We're trying to change views on that," he said, "but it's a slow process."
Even the process of recycling can be stifled by regulations which differ between countries.
"You can't have one set of rules for the outbound leg of a flight and another for the inbound leg, it just gets far too difficult for the staff to cope with," Goater explained. "So in the end it just gets thrown away."