Carriers were accused of failing to face up to these vital challenges in a BBC Panorama expose on Monday night (11 November) which asked: “Can flying go green?”.

Ahead of the show, the BBC called out British Airways for its practice of “fuel tankering” – operating aircraft with excess fuel to avoid filling up at destination airports.

The primary benefit of fuel tankering is to save money, but it comes at the expense of increasing carbon emissions owing to aircraft having to carry additional weight.

BA, though, said tankering was not exclusive to BA and was a sector-wide practice, employed to mitigate fluctuations and disparities in fuel costs in different countries and at different airports, and for operational reasons such as where turnaround times are too tight to adequately refuel upon arrival.

The show assessed a number of developments within aviation that could make flying greener such as new fuels, electric aircraft, and more stringent enforcement of preventative climate change action set out in international agreements.

However, despite investment by the likes of IAG and Virgin Atlantic in alternative fuel technology and production – particularly bio-fuels, and initiatives like easyJet’s partnership with Wright Electric to develop a battery-powered aircraft or Pipistrel’s electric aircraft, which featured in the show – many of the solutions are yet to become scalable or cost-effective.

Carbon offset programmes, meanwhile, have grown in popularity in recent years, with some efforts already being levied by the likes of Ryanair on air fares, albeit optionally.

IAG last month pledged to achieve net-zero carbon emissions by 2050 and has vowed to offset all emissions from BA’s domestic flying programme next year by investing in carbon offsetting projects around the world. Activist travel company Responsible Travel branded the move “the worst case of greenwashing”.

Qantas on Monday announced it was immediately doubling the number of flights it would offset, while offsetting all emissions arising from Project Sunrise, its effort to put non-stop flights from Australia’s east coast to London and New York on a commercial footing.

Offsetting ’not working as climate tool’

Professor David Lee from Manchester Metropolitan University, who has written extensively on aviation and climate change with a particular focus on fuel and emissions, told Panorama it would be decades rather than years before a reliable supply of renewable fuel would become available for deployment throughout commercial aviation.

Andrew Murphy, aviation manager at environmental NGO Transport and Environment, branded carbon offsetting “the most flawed climate tool”.

“We have 20 years’ experience globally of trying to make offsetting work,” said Murphy. “We’ve had windfarms that we were going to build anyway [and] trees that ended up being burned down. It’s not working as a climate tool.

“But at the same time, the aviation industry is increasingly seeing offsetting as essentially its get out of jail card for climate policy.”

The International Civil Aviation Organization, however, said offsetting was just one of numerous measures states and the industry were pursuing to limit emissions.