Environmental regulators are ultimately hurting business and trampling on European competition, Ryanair CEO Michael O'Leary told CNBC on Tuesday.
Speaking on Squawk Box Europe, O'Leary called existing greenhouse gas regulations "absolute bloody nonsense," and criticized taxes on the travel industry as a misguided move.
"If you can stand it up, and you're actually going to make some contribution, then fine. Taxing air travel simply because you want to be seen to do something … it does nothing for the environment," O'Leary said.
"Ultimately all it does is reduce European competitiveness," he added.
However, Chris Hope, a climate change researcher at Cambridge University, told CNBC in a phone interview that taxes on greenhouse gases did the exact opposite.
"It makes countries which impose these taxes more competitive. With the added revenue, they can reduce other taxes. They can reduce income taxes or payroll taxes, and they have a choice. But it will stimulate economies," Hope said.
O'Leary's comments come as global leaders gear up for COP21, the global climate change conference set to take place in Paris from November 30 to December 11 this year. It's expected to deliver a legally binding agreement between over 190 countries that would aim to keep global temperatures from rising more than 2 degrees Celsius.
But O'Leary wasn't so optimistic.
"They'll come up with some bogus and rubbish statement at the end of it. Will it make any difference? No...The Europeans will find some way to reduce our competitiveness as a result of it. And the Russians, the Indians, the Chinese will laugh at us," he said.
"Unless you can get the Russians and the Chinese and the Indians on side, frankly Europe is simply sitting there, appealing to some middle class angst and raising taxes," he added.
Action from Europe, though, could be the catalyst that gets emerging markets on board, Hope said.
"If we're able to have strong climate change policies in place, showing that economies grew more with them than without them, and by reducing other distortionary taxes, there's every indication that India and China, would see it in their own best interest to do so, too," Hope explained.
"But it really does fall to us to be the demonstrator on this, and be the leaders that show that it does work," Hope added.