There are signs of "fading traffic momentum" at Europe's airports, with airlines becoming more risk-averse and focused on protecting their yields, according to the European arm of Airports Council International (ACI).
Last year, Europe's airports handled 2.34 billion passengers - a record. Over the past five years, passenger numbers at the gateways have risen by 36pc.
"There are signs that the traffic momentum is fading for Europe's airports," warned ACI Europe director general Olivier Jankovec.
"A synchronised slowdown in the global economy and significant geopolitical risks are combining with volatile oil prices, ATM [Air Traffic Management] disruptions and overcapacity to exert downward pressures on both demand and supply," he said.
ACI Europe said that airline bankruptcies, and airport capacity constraints at peak times in particular, are negatively impacting air connectivity. It added that air connectivity in Europe is expanding by 1.2pc this year, with connectivity in the Europe-North America market actually dipping by 0.8pc.
Dublin Airport is seeing expanded connectivity to North America this year, with new routes to cities including Dallas, Calgary and Minneapolis-St Paul.
But Cork and Shannon airports have suffered with a reduction in connectivity to North America. Norwegian has suspended transatlantic services from both airports due to the worldwide grounding of Boeing's 737 Max jets, which the airline used on the routes.
It now looks like the 737 Max faces further delays before its recertification by global aviation safety authorities after the US Federal Aviation Administration said it had detected a new potential risk during simulator tests.
New figures from the Irish Tourism Industry Federation show that passenger numbers at Dublin Airport rose 4pc in May to just under three million, and by 9pc at Cork to 240,000. Both airports are controlled by the DAA.
At Shannon Airport, which is operated by the Shannon Group, passenger numbers fell 6pc to 165,000 in May, and were down 6pc to 603,000 in the year to date.
ACI Europe said that airline hybridisation - with low-cost carriers establishing presences at primary airports and legacy carriers focusing growth on their own low-cost carrier operations - coupled with airline consolidation is putting more competitive pressure on airports.
"We are still far from the concentration levels of the US airlines, but there is little doubt that this is where the European market is going to go - even if at a slower pace," said Mr Jankovec.
"As the European Commission rightly noted last year airports are becoming the battlegrounds for airline dominance," he added, claiming that as a result, airlines are opposed to airport investment.