Climate activists branded yesterday’s agreement to halve airline emission by 2050 as “complete greenwash”.

Greenpeace said the package did not go far enough and that it was a cynical effort to avoid new taxes that threaten to erode into the industry’s profits.

Vicky Wyatt, aviation campaigner at Greenpeace, said that the majority of cuts would be achieved through a carbon-trading regime rather than a real reduction in the industry’s emissions.

International pressure has been mounting to use a tax on aviation to fund programmes designed to assist developing countries to tackle climate change as well as protect them from its worst effects.

Speaking on behalf of the International Air Transport Association, BA Chief Executive Willie Walsh said the proposals represented “the most environmentally effective and practical means” of cutting the 2-4 per cent of global emissions produced by passenger aircraft.

Giovanni Bisignani, the director-general of IATA, said that the industry was opposed to “punitive taxes that fill government coffers but do little or nothing to effectively manage aviation’s emissions”.

IATA also announced other measures designed to help to cut the industry’s emissions, including a proposal for 10 percent of the world’s aircraft fuel to be derived from biofuels by 2017.

Kati Ihamaki, vice-president for sustainability at Finnair, which has been closely involved in drafting the proposals, said they would boost greener technologies, including more efficient engines and lighter aircraft.

They would also mean that in future airlines would be encouraged to operate aircraft more efficiently, including slower flight speeds, greater use of prevailing winds and even fly in formation to help conserve fuel, she said.

A shake-up in air traffic control systems would help to reduce emissions by encouraging the use of more direct routes between cities, she added.

Vicky Wyatt told The Times that the announcement was “little more than an elaborate conjuring trick designed to make the public think that BA is serious about climate change while it carries on with business as usual. The focus must be on reducing demand for flights.”

Government figures suggest that without action to curb aviation emissions they could increase fourfold by 2050 to 2.4 gigatonnes.