War zones causing airlines to drive up carbon footprint

Airlines have burnt through 13 per cent more jet fuel to avoid Russia and Ukraine's air space during the war in Europe, dealing a blow to air travel's efforts to cut its environmental footprint.

Carbon emissions from flights from Asia to Europe were up by more than a sixth due to tit-for-tat airspace closures linked to the war, a study revealed on Wednesday. The impact dwarfed that of Middle East airspace closures linked to armed conflicts in Syria, Libya and Yemen.

Russia's vast territory, spanning 11 time zones, is off limits to most US and European carriers under a ban imposed by the Kremlin in retaliation at western sanctions. Russian airspace is still used by domestic flights as well as some Middle East and Asian airlines. Russian aircraft are similarly banned from flying over UK and EU territory.

Commercial flights over Ukraine have also been suspended since the February 2022 Russian invasion, forcing many flights to reroute. Insurers in London have held talks about getting air traffic back off the ground, but European regulators continue to advise against using Ukraine's airspace because of the risk of attacks and of civilian aircraft being mistaken for warplanes.

Flight paths are designed to optimise fuel use but the detours due to political tensions put a “major obstacle” in the way of more efficient and environmentally friendly air travel, University of Reading meteorologists said. They said the extra journey time caused by the war in Ukraine amounted to about 1 per cent of all flying emissions in 2023, as airlines took longer journeys south of Russia or over the Arctic.

“The affected flights make up about 1,100 flights per day, but the extra distance they must fly has a notable impact on aviation's overall carbon footprint,” said Nicolas Bellouin, a meteorologist who co-wrote the study. “These detours added 8.2 million tonnes of CO2 to global aviation emissions in 2023.”

During the war's first two years about 1,800 flights a day were affected by the need to avoid Ukrainian and Russian airspace, according to the study. By contrast, no more than 100 flights a day had to be rerouted to stay out of Libyan, Syrian or Yemeni territory.

The three Middle East closures added about 0.2 per cent to global emissions in 2023 – while trips that circumnavigated Russia and Ukraine contributed five times more. “These flights are among the longest flights worldwide and, even though they account for a small percentage of the flights, they account for a disproportionally large fraction of the emissions,” the study said.

Fuel consumption was 13 per cent above the norm for all affected flights, and higher still when planes have to plot routes with stronger headwinds, such as on the way from Asia to Europe, where flights churned out almost 17 per cent more CO2. Members of the International Civil Aviation Organisation have a 2050 net zero target for flying.

The study, Airspace restrictions due to conflicts increased global aviation’s carbon dioxide emissions in 2023, is published today in the journal Communications Earth & Environment.