Tony Blair is opposed to clawing back any of the aviation industry's annual �9bn subsidy or introducing new taxes to limit airlines' impact on the environment, he told a parliamentary committee today. The PM told the Commons Liaison Committee he didn't believe 'restrictions on air travel at an international level' would cut passenger numbers, which are scheduled to double by 2020 and triple by 2030 � and could be responsible for as much as 60 per cent of all greenhouse gas emissions by 2050. Environmentalists across the EU have condemned what is being seen as a U-turn on UK environment policy, warning the PM's decision will hasten damaging climate change. Euro-MP Caroline Lucas, who is currently drafting a report for the European Parliament examining aviation's impact on climate change, said the only way to rein in aviation's greenhouse gas emissions was to reduce demand by a range of economic and fiscal measures. Dr Lucas said: "This is an extraordinary abrogation of duty: and one which finally puts the lie to this Tony Blair's much-hyped 'green credentials'. "Aviation is the fastest growing source of greenhouse gases, already responsible for more than five per cent of all the EU's emissions, with passenger numbers set to triple in the UK by 2030.