British Airways boss Willie Walsh has hit out at a central plank of industry efforts to counter environmental criticism.

The BA chief executive said the industry made a “massive mistake” by repeatedly asserting aviation accounts for just 2% of global greenhouse-gas emissions. This is the airlines’ contribution to worldwide carbon-dioxide emissions, according to the Intergovernmental Panel on Climate Change, although climate scientists now estimate aviation contributes nearer 3%.

Walsh told industry leaders at an Aviation and Environment Summit in Geneva: “It was a massive mistake to try to play down the impact of aviation – the biggest mistake the industry has made. I do not buy into this 2% – it is not trivial, it is a massive amount.”

He added: “Some of the criticism levelled at our industry is fair. Compared with other industries, we seem to have got away free. The perception that aviation has a free ticket must be addressed.”

Walsh told the summit, organised by the industry’s Air Transport Action Group, that agreement on a worldwide emissions trading scheme at the inter-governmental climate conference in Copenhagen at the end of the year was essential.

“There is a real risk to our industry if we are not seen to make progress at Copenhagen,” he said. “We will suffer at the hands of politicians who see us as fair game for taxation.”

The European Union plans to include airlines in a regional emissions trading scheme from 2012. Most carriers are opposed, although BA has supported the move as a step towards a global scheme.

Walsh warned that progress on reducing airline emissions would not be easy and called for competition on the issue to be put to one side.

“We have to be realistic – the industry faces its greatest-ever crisis,” he said. “There is a tendency to compete on the environment, but let’s not do that.”

That call was echoed by Swiss International Air Lines chief executive Christoph Franz, who said: “It is no good [airlines] arguing ‘we are clean and they are the dirty guys’.”

But he warned: “This industry is structurally not profitable enough and if we have no money, there will be no green aircraft even if the technology is available. The industry has to become more profitable to be able to afford it.”

In the meantime, the BA boss sees little hope of the UK government abandoning Air Passenger Duty on air fares, despite industry lobbying. ABTA repeated its call for APD to be scrapped last week following the Dutch government’s removal of its aviation tax.

n Representatives of the world’s 49 poorest countries have called for a $6 levy on every flight to help states adapt to climate change. The proposal was presented at United Nations climate talks in Bonn this week and could go forward to the Copenhagen conference.