Ryanair says it will be bringing in a new levy of 25 cent per passenger for all bookings made from next Tuesday January 17.
The airline has blamed the new levy on the EU's emissions trading scheme (ETS). Ryanair claims the scheme - which it has labelled an "eco-loony" tax - will cost it €15m to €20m this year.
Last month, the EU's highest court ruled that the EU could make all airlines flying to or from European airports pay to offset their carbon emissions from January 1.
From January 1, the EU set a cap on the amount of carbon dioxide airlines can emit. Carriers now have to buy emissions permits to land or take off in the EU under the ETS.
The EU said airlines would receive 85% of their emissions allowances free of charge in 2012, a figure that will drop to 82% a year between 2013-2020. The EU admitted last year that the scheme could prompt airlines to push up fares.
