The International Air Transport Association (IATA) reported that global cargo volumes are rising significantly, with worldwide cargo tonne-kilometres "much improved" at -13.5% year-on-year in July.
However, IATA noted that traffic varies "tremendously" by trade lane, ranging from +4% for Asia Pacific-North America to -30% for Europe-North America.
The US-China trade, meanwhile, decreased 0.8% in July, as US-Germany trade decreased 13%.
IATA said the variation relates partly to demand but is mainly due to differences in capacity caused by the lack of bellyhold capacity from widebody passenger aircraft.
Prior to the coronavirus crisis, freighter aircraft accounted for 75% of North Pacific traffic, compared to only 42% for the North Atlantic and 29% for the within Asia market.
Now the figures are 90% for North Pacific, 75% for North Atlantic and 63% for within Asia, due to the redeployment of fleets and elevated utilisation of freighters.
"Clearly a major problem for airlines responding to the demand for air cargo is a lack of the right sort of aircraft in the right place," IATA said.