IATA downgraded its 2020 traffic forecast following a "dismal end to the summer travel season" in the northern hemisphere and now expects it to be 66% below the level in 2019, a statement said.
IATA's previous forecast was for a drop of 63%, but that was before government reimposed travel restrictions in August and the outlook faltered for the rest of the year, it added.
The association, which represents 290 airlines, said that August traffic, which it measures in revenue passenger kilometers or RPKs, plunged by 75.3% from the same period in 2019.
A resurgence in coronavirus cases since then and more government restrictions to deal with them, has prevented a strong rebound.
"A much slower improvement is now expected," the statement added.
"Absent additional government relief measures and a reopening of borders, hundreds of thousands of airline jobs will disappear," said chief executive Alexandre de Juniac.
He called for an international program of COVID-19 tests prior to a flight's departure to give governments the confidence to open borders and passengers confidence to board planes again.
A breakdown of the industry data indicated that domestic flights were attracting more passengers than international services, though in countries such as Australia and Japan, even domestic flights were way down. (READ: European airlines cutting fares to woo back passengers)
IATA has estimated that global traffic will not reach pre-pandemic levels before 2024, and that the sector will earn $419 million less this year owing to the pandemic. (READ: Bailout will keep Air France-KLM afloat for less than year – CEO) – Rappler.com