Dubai International Airport retained the <a href="https://www.thenationalnews.com/business/2022/02/22/dubai-remains-worlds-busiest-international-hub-with-291-million-passengers-in-2021/" target="_blank">title </a>of the <a href="https://www.thenationalnews.com/business/aviation/2022/01/06/dubai-retains-title-as-worlds-busiest-international-airport-in-december/">world's busiest international hub</a> for passengers in 2021, as air travel demand continues to recover, rankings by the Airports Council International (ACI) show. Istanbul, Amsterdam, Frankfurt and Paris followed Dubai as the top five busiest airports by international traffic, the trade association for airports worldwide said on Monday. Dubai, which does not have a domestic market, recorded a 12.7 per cent increase in passenger traffic year on year to 29.1 million in 2021. “The ACI World passenger traffic rankings tell the story of an encouraging trend of recovery, with most of the recurrent busiest airports pre-Covid-19 back at the top,” ACI World's director general Luis Felipe de Oliveira said. “Although we are cautious that recovery could face multiple headwinds, the momentum created by reopening plans by countries could lead to an uptick in travel in the second half of 2022." Global airlines and airports, emerging from the two-year Covid-19 pandemic that shattered air travel demand, are now facing <a href="https://www.thenationalnews.com/business/2022/04/07/global-airlines-expect-airfares-to-rise-faster-as-fuel-prices-spike/" target="_blank">steep rises in jet fuel costs</a> and <a href="https://www.thenationalnews.com/business/2022/04/07/global-airlines-expect-airfares-to-rise-faster-as-fuel-prices-spike/" target="_blank">staff shortages </a>as they try to resume operations as travel rebounds. Hartsfield-Jackson Atlanta International Airport topped the rankings by overall passenger traffic last year, returning to the list with a 76.4 per cent year-on-year increase in traffic of 75.7 million travellers, ACI data showed. The rankings are based on the preliminary compilation of 2021 global data from airports around the world, and take into account their domestic and international markets. Dallas/Fort Worth International Airport, Denver International Airport, Chicago's O'Hare International Airport and Los Angeles International Airport rounded off the top five. Eight of the top 10 airports for passenger traffic are in the US, with the two remaining in China, per ACI estimates. Guangzhou Baiyun International Airport and Chengdu Shuangliu International Airport were the two Chinese airports on the top 10 list. China's international borders stayed shut last year and the country's domestic traffic fell as a result of its zero-Covid policy that led to strict travel restrictions, dampening demand. Orlando International Airport recorded the biggest improvement, jumping to seventh spot in 2021 from 27th position in 2020. Orlando, home to Walt Disney World and Universal Studios Florida theme parks, benefited from soaring leisure travel in the US. "All top 10 airports have a significant share of domestic traffic, the traffic segment that has been leading global recovery," ACI said. The total number of global passengers in 2021 is estimated to be nearly 4.5 billion, representing an annual increase of about 25 per cent and a drop of more than 50 per cent from 2019, before the pandemic, ACI said. Passenger traffic at the top 10 busiest airports accounted for almost 10 per cent of total global traffic, it said. This represents an increase of almost 52 per cent from 2020 but a drop of 29 per cent from 2019. Global air cargo volumes, meanwhile, increased nearly 15 per cent year on year to an estimated record 124 million metric tonnes in 2021, ACI data revealed. "The gain can be attributed to the continued increase in demand for online consumer goods and pharmaceutical products," the trade body said.