The looming threat of a global trade war and soaring fuel prices are casting a “long shadow” over airline passenger growth.
The warning was issued by Iata despite a rise in demand in June.
Latest global passenger traffic figures show that demand rose by 7.8% in the month, up from 6% in both April and May.
June capacity increased by 6.5%, and the load factor rose by a single percentage point to 82.8%.
The first six months of 2018 produced demand growth of 7%, down from 8.3% growth recorded in the first half of last year.
The aviation trade body’s director general and chief executive Alexandre de Juniac said: “The first half of 2018 concluded with another month of above-trend demand growth, which is a good indicator for the peak summer travel season in the northern hemisphere.
“But the looming prospect of a global trade war is casting a long shadow.
“Additionally, rising cost inputs – fuel prices have soared by approximately 60% over the past year – are reducing the stimulus of lower fares.”