The agreement brings the aviation industry - one of the fastest-growing emitters of greenhouse gases - into Europe's Emissions Trading Scheme for the first time.

And it is being hailed as a major advance in helping meet EU international obligations on cutting carbon dioxide emissions.

The European Commission said it was a significant step in the fight against climate change - but acknowledged that it would eventually mean higher air ticket prices for travellers.

``Fully passing on costs to customers would mean that by 2020 airline tickets for an [average] return journey could increase by €4.60 euros to €39.60 depending on the journey length,'' said the Commission's impact assessment report on the controversial plan.