Image copyright Reuters Image caption Etihad is the first major airline to take a single-use plastic-free flight

Attention has turned in recent months to how much plastic can be found in our oceans - but what about the plastic in our skies?

The Abu Dhabi-based Etihad Airways recently revealed that it uses some 27 million single-use plastic coffee cup lids every year.

That revelation was enough to encourage Etihad to take action and, on 22 April, it became the first major airline to make a long haul flight with no single-use plastics on board.

To achieve this feat - which coincided with World Earth Day - it needed to replace no less than 95 different single-use plastic items.

Among the replacements were edible wafer coffee cups and blankets made from recycled plastic bottles. Where suitable replacements could not be sourced, the items were not loaded.

"There is a growing concern globally about the overuse of plastics, which can take thousands of years to decompose," Tony Douglas, the group's chief executive, explained.

"We discovered we could remove 27 million single-use plastic lids from our in-flight service a year and, as a leading airline, it's our responsibility to act on this, to challenge industry standards and work with suppliers who provide lower impact alternatives."

Image copyright Getty Images Image caption Airlines are aiming to reduce their reliance on single-use plastics

The future - or a publicity stunt?

So are we looking at a future of air travel without disposable plastic? Or is this a one-off publicity stunt?

"Anything that reduces the impact of air travel on the planet has to be welcomed, and Etihad is making a bold move in the right direction," Simon Calder, senior travel editor at The Independent, told the BBC.

However, Mr Calder had reservations about how seriously both airlines and customers are about reducing the impact that flying has on the environment.

"Airlines like to stage publicity stunts to try to emphasise their green credentials," he said.

"But if airlines - and travellers - were really serious, they would not, respectively, supply or demand extremely luxurious on board products."

Mr Calder pointed to "The Residence" - a three-room "suite in the sky" offered by Etihad that comes complete with butler service - as one of the most harmful services offered by airlines.

Etihad says it is committed to improving its environmental policies beyond the Earth Day flight, pledging to reduce single-use plastic usage by 80% across the entire organisation by the end of 2022.

But Mr Calder said that the aviation industry and its customers still had a long way to go on all matters "green".

"And while I would love to think that air passengers seek out the lowest-impact aircraft and airlines, the evidence is that they don't - otherwise British Airways would not be keeping on its 25-year-old fleet of gas-guzzling Boeing 747s," Mr Calder added.

"BA has the highest number of any airline, and intends to keep flying them until the end of 2022."

Despite Etihad being the first major name to scrap single-use plastic for a long-haul flight, Hi Fly, a Portuguese charter airline, was the first to fly plastic-free in December.

Ryanair has also pledged to scrap single-use plastic by 2023 and hopes to gain the title of "the greenest airline", while Alaska Airlines has stopped using plastic straws.

Media playback is unsupported on your device Media caption The metal box that accidentally discovered the history of ocean plastics.

Is it enough?

Julian Kirby, a lead campaigner on plastics for Friends of the Earth, said that while plastic reduction by big businesses should be welcomed, there should be greater efforts made.

"Plastic pollution has an enormous impact on our environment and wildlife, so every company should be taking steps to pull the plug on non-essential single-use plastic," Mr Kirby told the BBC.

"If Etihad Airways can fly without single-use plastics on Earth Day - why can't it do so every day?" he said.

Mr Kirby pointed out that plastic consumption was fairly low down on the environmental problems the aviation industry is causing.

"Of course aviation's main impact isn't plastic pollution - it's climate change," he added.

"If planes continue to pump more pollution into our atmosphere the world will struggle to prevent catastrophic climate change."