How extreme weather is hitting airlines

Storms, wildfire smoke and heat that reduces aircraft lift have disrupted flights this summer

Claire Bushey in Chicago and Philip Georgiadis in London | Financial Times | August 17 2021

Some airlines and airports have started to plan for a future where severe weather jolts flight schedules more frequently, as climate change increases the likelihood of extreme heat and big storms.

This month, storms forced the cancellation of more than 300 flights at both Chicago's O'Hare airport and Dallas/Fort Worth airport in Texas. In July, eight flights in Denver were cancelled and another 300 delayed due to smoke from forest fires burning in the US Pacific Northwest. Extreme heat affected take-offs in Las Vegas and Colorado earlier this summer.

The disruptions are in line with a trend: weather-related flight cancellations and delays have increased over the past two decades in the US and Europe, regulatory data shows. While it is difficult to link any individual storm or heatwave to climate change, scientific studies have found they will become more frequent or intense as Earth grows warmer.

The International Civil Aviation Organization, the UN standard-setting body, found in a 2019 poll of member states that three-quarters of respondents said the airline industry already was experiencing some impact from climate change.

"It is something that is absolutely on our minds, as far as how we're going to be able to continue to run the flight schedule, especially with the growth that we have planned for the future," said David Kensick, managing director of global operations at United Airlines. "With climate change, we are seeing some of that weather that's hard to predict, so we need to be better at dealing with it."

Airlines contribute about 2 per cent of global carbon-dioxide emissions globally, though counting other substances spewed from aircraft, some studies indicate their climate impact is bigger.

The potential impacts of climate change on the industry are far-reaching. In the short term, intense weather conditions present an operational headache. Forced flight diversions and cancellations add costs to an industry that haemorrhaged billions of dollars during the pandemic.

In the longer term, airlines believe changing wind patterns will alter flight routes and fuel consumption. It will probably take longer to fly from Europe to the US as the jet stream above the north Atlantic changes, for example.

"Aviation will be a victim of climate change as well as, in many people's eyes, a villain," said Paul Williams, professor of atmospheric science at the University of Reading in the UK.

The number of delays attributed to bad weather in European airspace rose from 3.5m in 2003 to a peak of 6.5m in 2019, according to data from Eurocontrol, although some of that can be attributed to industry growth. As a share of overall delays, weather rose from 23 per cent to 27 per cent over the same period.

The share of US flights that were cancelled because of weather increased from approximately 35 per cent in 2004 to 54 per cent in 2019, according to the Federal Aviation Administration.

Mark Searle, global director for safety at the International Air Transport Association, said airlines had adapted over the years to the changing climate.

"There is an evolving situation, but it is not like going off a cliff edge," he said. "We are managing it pretty darn well."

For airports, that can mean preparing for rising seas. Singapore Changi Airport's new passenger terminal was constructed 5.5 metres above mean sea level. Avinor, the operator of airports dotted along Norway's coastline, has mandated that all new runways must be built at least 7m above sea level.

For airlines, it means turning to technology. American Airlines and United have improved their ability to predict the proximity of lightning, allowing work on the tarmac to continue for longer ahead of a brewing thunderstorm without endangering ground staff.

At several hubs, Chicago-based United Airlines also added self-parking systems to allow planes to taxi to the terminal even when storms prevent ramp agents from guiding them to gates.

Severe weather demands extra staff. Carriers are forced to pay overtime as gate agents and call centres facce extra demand from passengers trying to rebook. Airlines will need to weigh up paying more overtime, instituting extra work shifts, or letting passengers endure the fallout.

"There's going to be extra cost either way if - and this is a big if - the airlines decide they're going to address it," said Jon Jager, an analyst at the aviation data firm Cirium.

While passengers typically blame airlines, the rules of the US, UK and EU do not require airlines to compensate passengers for weather-related problems. "Mother Nature gives the airlines a little bit of a get-out-of-jail-free card," Jager said.

Disruptions come not only from storms, but from extreme heat. Aircraft struggle to take off in high temperatures because hot air is less dense, meaning the wings are able to create less lift. The hotter the temperature, the lighter a plane must be to take off, particularly at airports with short runways or at high altitudes.

Williams, the atmospheric scientist, published a paper that found that for an Airbus A320 taking off from the Greek island of Chios, the payload has decreased about 130kg a year for three decades - roughly equivalent to one person and their luggage.

Iata is in talks with its members over adopting new climate change pledges later this year. The industry's current targets, set in 2009, include halving 2005 emissions by 2050 and carbon neutral growth after 2020.

But there is a belief across many parts of the industry, particularly in the US and Europe, that tougher targets, including a net-zero pledge, are needed.

"We think that we should probably go further, so we are working on that," Alexandre de Juniac, Iata's outgoing chief executive, told the Financial Times earlier this year.

Williams said the aviation industry's approach to climate change appeared to be shifting.

"Historically, there have been lots of climate change sceptics in the aviation sector, but I've noticed a change," he said. "The sector is much more honest now."