Climate and science.
According to a new report, UK airlines have missed all climate targets since 2000.
The aviation industry has its own goals.
The UK aviation industry is committed to reducing its greenhouse gas emissions.
The charity behind the research wanted to know if airlines could be relied upon to tackle their role in causing emissions that lead to climate change.
Companies set grand-sounding targets with a lot of fanfare. They talk about them for a couple of years, then the targets sink without trace, according to Possible.
Since 2000, airlines have set environmental goals. Greener fuels to power airplanes or making fuel more efficient are some of the targets.
The only company that met a target was EasyJet. The fuel burn per passenger kilometre was reduced by 3%.
It may have missed other goals, including a plan to build a plane that would emit 50% less CO2 than its current planes. In 2009, the company appeared to drop the target and the ecoJet was never built.
The ecoJet was a prototype concept that was used to urge the industry to produce planes that reduce carbon emissions. A spokesman for EasyJet said that the company's ultimate ambition is to achieve zero carbon emission flying.
Virgin Atlantic said that 10% of its fuel would be biofuel by 2020. The target was not mentioned again. Virgin Atlantic will use 10% alternative fuels by 2030.
The charity claims that Richard Branson did not deliver on his promise to fight global warming.
Virgin didn't reply to the request for comment.
There are no good alternatives when it comes to technological solutions because the industry is inherently high-carbon. The volume of flights has grown faster than efficiency has improved.
The chair of the industry body, the sustainable aviation Coalition, told the news organization that technology improvements mean growth in passengers no longer means growth in emissions and that the industry continues to innovate to reduce emissions further and faster. Decarbonising aviation is a huge challenge, but the solutions are real and being implemented.
Mr Murray said that the findings undermine the government's plans to drastically reduce the UK's greenhouse gas emissions.
The Jet Zero strategy is likely to rely on airlines decarbonising in order to tackle the role of aviation in climate change. The industry would use technology to fix its emissions problem.
It is a very high-risk strategy. The government is putting all its eggs in the basket of aviation meeting their own goals, but their track record is terrible, according to Mr Murray.
The government believes that we can keep flying and still reach net zero by the year 2050.
It says that innovation will save the day. The policy is called into question by this report.
The government will need an alternative strategy if the aviation industry can't find ways to make planes more efficient.
If you want to manage demand, you should make it more expensive to fly often.
A small number of people do most of the flying. Only 15% of people take all flights.
The public supports a frequent flier levy.
The tax on the first flight in a year could be little or no.
The Climate Change Committee blamed the government for failing to reduce demand for flying.
The report ignores the historic investment in technology, fuel and market-based measures which will help us reach Jet Zero without the need for further taxes, according to a Department for Transport spokesman. The funds will be used to accelerate sustainable aviation fuel and to develop zero-carbon and low emission aircraft technology.
Making sustainable transport like high-speed rail or ferries more affordable and accessible should be prioritised by the government.
One scheme he runs encourages employers to give workers extra holiday days to allow them to travel abroad by train or ferry, which has a lower carbon footprint but can take much longer than flying.