Charging for toilets, weighing passengers and flying with a lone pilot: Ryanair's combative boss Michael O'Leary is renowned for backing unusual ideas, but some passengers may feel that even he has overstepped the mark with his latest comments – denying the existence of global warming.
In an interview with The Independent littered with expletives, the chief executive of Europe's largest airline branded the scientific consensus that man-made pollution is heating up the planet with potentially grave consequences for the future of humanity as "horseshit".
He agreed the climate was changing but denied it was caused by man-made emissions of carbon dioxide, such as those from his planes. "Nobody can argue that there isn't climate change. The climate's been changing since time immemorial," he said.
"Do I believe there is global warming? No, I believe it's all a load of bullshit. But it's amazing the way the whole fucking eco-warriors and the media have changed. It used to be global warming, but now, when global temperatures haven't risen in the past 12 years, they say 'climate change'."
"Well, hang on, we've had an ice age. We've also had a couple of very hot spells during the Middle Ages, so nobody can deny climate change. But there's absolutely no link between man-made carbon, which contributes less than 2pc of total carbon emissions [and climate change]."
He suggested scientists had invented and perpetuated the theory in order to gain research grants. "Scientists argue there is global warming because they wouldn't get half of the funding they get now if it turns out to be completely bogus," he said.
"The scientific community has nearly always been wrong in history anyway. In the Middle Ages, they were going to excommunicate Galileo because the entire scientific community said the Earth was flat... I mean, it is absolutely bizarre that the people who can't tell us what the fucking weather is next Tuesday can predict with absolute precision what the fucking global temperatures will be in 100 years' time. It's horseshit."
He mocked global warming campaigners, describing the United Nations as "one of the world's most useless organisations", its Intergovernmental Panel on Climate Change (IPCC) as "utter tosh", and US politician Al Gore as someone who "couldn't even get fucking re-elected" after a boom.
Of air passenger duty in Britain, which will rise by between £1 and £30 in November, Mr O'Leary said: "When they introduced it the Treasury said: 'We will ring-fence this money and use it for global climate change initiatives'.
We've written to them once every six months – they never answer the letter – saying: 'What do you use the money for?' It's a straight-forward tax scam... My average fare is £34. I pay passenger tax of £10: I pay 33pc of my revenues in these aviation taxes.
"Aviation gets a crap deal. This is the great historical justification among environmentalists for taxing air travel: 'They don't have tax on fuel'. The only reason we don't pay tax on fuel is that governments can't tax it because you'll upload fuel somewhere else if they tax it."
To date, the US, UK, Germany, Japan, India, and China have all agreed on the existence of global warming, but have failed to agree binding emission targets to limit it. More than 2,500 scientists contributed to the IPCC's fourth assessment report in 2007, which warned that freak weather events such as flooding and drought will intensify, threatening agriculture and the livelihoods of millions.
Greenpeace issued a light-hearted response to Mr O'Leary's comments. "Personally, I wouldn't trust 'O'Really' to tell me the price of a seat on his own airline, but to be fair his position does have the support of such intellectual heavyweights as Nick Griffin, Sarah Palin and George W Bush," said Joss Garman, a Greenpeace spokesman.
O'Leary's views: A rebuttal
O'Leary "The climate has been changing since time immemorial. Do I believe there is global warming? No, I believe it's all a load of bullshit."
Dr Emily Shuckburgh, of the British Antarctic Survey "Over tens of thousands of years, the orbit of the Earth about the Sun slowly varies, and with it the amount of solar radiation that reaches the Earth's surface. When the orbit is such that the radiation dips low enough, it triggers an ice age. Since the Earth has not suddenly jumped into a different orbit in the past century, a different mechanism must explain the recent increase in global temperatures."
O'Leary "It used to be global warming but now, when global temperatures haven't risen in the past 12 years, they say 'climate change'."
Dr Shuckburgh "It is wrong to say global warming has stopped in the past 12 years. The weather changes day to day, and even when the temperature is averaged globally and over a full year, there are still considerable variations from year to year. When this is taken into account, no reduction is found in the global warming trend of 0.15-0.20C per decade."
O'Leary "There's absolutely no link between man-made carbon – which contributes less than 2pc of total carbon emissions, most of it is naturally emitted – [and] climate change."
Dr Shuckburgh Vast amounts of carbon are exchanged each year back and forth between the land, oceans and atmosphere – some 200 GtC/yr [GigaTons of Carbon per year] are naturally emitted and 200 GtC/yr are naturally reabsorbed. Man is now emitting more than 8GtC/yr, about half of which remains in the atmosphere. The impact has been significant. Before the Industrial Revolution, carbon dioxide levels were about 280ppmv [parts per million by volume]. Man-made emissions have increased that to nearly 390ppmv.
O'Leary "The same [scientific] community was telling us in the mid-1970s the world was heading into a new ice age. I mean, it is absolutely bizarre that the people who can't tell us what the weather is next Tuesday can predict with absolute precision what the global temperatures will be in 100 years' time."
Dr Shuckburgh Of course it is not possible to predict with precision the weather in 100 years. But we can characterise – to within a range – the long-term climate trend that underlies the chaotic weather.
O'Leary "The IPCC [ Intergovernmental Panel on Climate Change] is a load of utter tosh."
Dr Shuckburgh The facts are that errors in the IPCC's fourth assessment report were identified and acknowledged, and the fundamental findings of the report were unaltered. This valuable scrutiny has strengthened, not discredited, the conclusions.
O'Leary "The only [IPCC economic growth scenario] that gives rise to this inexorable rise of man-made CO2 emissions linked to climate change... is 7pc compound economic growth into infinity. That's already been torn up in the last two years. We've already had a worldwide decline."
Dr Shuckburgh Carbon emissions do not have to rise inexorably for there to be climate change. If we stopped all emissions now, which is impossible, the temperature would increase for many years due to the emissions we have already made. Moreover, current CO2 emissions, even with the global recession, are in the mid to upper range of IPCC scenarios.