Ireland has been accused of not being "brave enough" to require its airlines - Ryanair and Aer Lingus - to pay taxes.
According to calculations from environment NGO, Opportunity Green, Ireland is leaving €760 million on the table last year due to its low aviation taxes, an European campaign group has said.
Due to the country's low levels of taxation on the aviation sector, Ireland is losing €760 million in revenue.
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If no action is taken by government and the aviation sector here grows as projected, the tax gap could be €950 million by 2025.
Ireland had a tax on all departing flights from 2008 to 2014 but exact figures on the amount of tax collected from this was never released.
Opportunity Green and Transport & Environment (T&E) analysed the revenues that could have been raised from air travel pricing if the sector didn't benefit from tax exemptions.
For example, Ireland does not have a taxation on kerosene - the plane fuel that is exempt from carbon taxes.
Ireland also doesn't have ticket taxes or VAT on aviation while carbon prices are only on flights within Europe.
In the EU, long-haul flights are exempt from the carbon emissions scheme.
At European level, governments missed out on more than €34 billion in revenue due to low levels of aviation taxes.
Head of Opportunity Green, Aoife O'Leary said: "Ireland is failing to reach its climate targets purely because it is not brave enough to require Ryanair and Aer Lingus to pay taxes.
"Aviation is the most carbon intensive form of transport and yet Ireland still failed to include aviation in its new Long Term Strategy on climate."
Transport is Ireland's second-most polluting sector.
The government's sectoral emissions ceilings want to see the sector reduce it's emissions by 50 per cent by 2030.
Minister for Transport, Eamon Ryan, recently said he would like to see aviation taxed to finances the Loss and Damage Fund.
"Eamon Ryan recently pointed out the injustice of aviation going untaxed while climate vulnerable countries require support to deal with the devastating impacts of climate change in their countries," O'Leary said.
"Ireland must ensure aviation pays its fair share of taxes.
"There is a clear opportunity to reduce pollution from aviation and achieve Ireland's climate goals, all while supporting those most at risk from climate disaster."
