How does climate warming affect your flight?

How does climate warming affect your flight?

Author, Theo Leggett

Role, BBC international business correspondent

Published 38 minutes ago

Reading time: 5 minutes

At the end of June, when the UK was experiencing one of the hottest heatwaves of the hot summer, towering thunderclouds were gathering over southern England and much of Northern Europe.

It was a Saturday, and thousands of passengers were heading to London's Heathrow and Gatwick airports to catch flights abroad as the holiday season begins. It promises to be a very busy day.

However, what happened next threw travelers into chaos.

Airspace became so congested that many scheduled flights were forced to wait on the ground as air traffic controllers struggled to maneuver planes around the storm. In the end, about 900 flights to and from the two airports were delayed, with some delays lasting as long as 11 hours. Dozens more flights were cancelled.

At airports across Europe, passengers expecting to fly to London also faced long waits and uncertainty.

The weather may have turned cooler in the UK now and passengers may soon forget the experience. But some in the aviation industry believe what happened in June should be seen as a warning sign.

The timing of this incident was clearly unlucky. But some worry that as the impact of global climate change intensifies, such events will only become more common, and weather systems may become increasingly unstable, increasing the likelihood of flight disruptions and driving up costs for airlines, airports and passengers.

Tim Atkinson, an aviation risk consultant and former pilot, said the very busy airspace over the UK and northern Europe means this area is particularly vulnerable.

For example, he believes that all London airports are likely to be affected by storms at the same time, which may have significant consequences in the air and on the ground.

"What we are seeing now is very rapid climate change," he said.

"We are moving from weather activity that renders airports inoperable, but which the system as a whole is largely able to cope with, to a situation where all London airports have the potential to simultaneously lose real-time operational capabilities in a very short period of time and with little warning, in circumstances that are almost impossible to predict."

He believes that if this happens, the disruption to passengers caused by the June incident may be minor in comparison - and may even be life-threatening. But how likely is this to happen?

severe weather activity

Thunderstorms are a matter of great concern to the UK's National Air Traffic Services (NATS) main control center in Swanwick, Hampshire.

When I visited, the weather was hot and humid, the sky was filled with unsettling dark clouds, and the surrounding area was being battered by violent thunderstorms.

At Terminal Control, which manages flights to and from airports in London and southern England, the same storm clouds are being continuously monitored. Crews track their movements using large radar screens while carefully studying weather forecasts.

Air traffic tends to come in waves throughout the day. It was lunchtime so traffic was relatively calm and the storm had yet to affect the main shipping routes. But activity is expected to intensify in the afternoon and crews have begun preparing for what could be a tough few hours.

Stormy weather can reduce available airspace, meaning air traffic must be restricted and rerouted. For example, if a plane is unable to land at a certain airport due to strong winds or other reasons, it may need to fly to another airport.

But this can create problems of its own; if too many unscheduled planes land at an already busy airport, the airport may not have enough infrastructure to accommodate them all.

Planes need fuel and a place to park. Passengers need food and various facilities. Eventually, if there is not enough space, the airport may even be able to deny access to all but emergency flights.

This is exactly the scenario Atkinson describes.

He warned that if Heathrow, Gatwick, Luton and Stansted needed to be diverted at the same time, flights from across the Atlantic and a large number of European flights may be looking for places to land at the same time, while some aircraft's fuel reserves are dwindling.

At the very least, it would cause significant disruption for passengers, who may end up being forced to land hundreds of miles from their destination.

But he believes it could also create "very serious risk events, such as a plane running out of fuel in mid-air."

The law requires planes to carry enough fuel to fly to another airport for an additional 30 minutes if needed.

However, not everyone shares Atkinson's concerns.

Andrew Charlton, a former airline executive who now runs Swiss-based aviation industry consultancy Aviation Advocacy, believes the risk is low.

"You always have to think of the worst-case scenario," he said. "But I also think we need to put the worst-case scenarios into their proper context."

"Yes, we can imagine that. But I'm pretty confident in the industry's ability to deal with the problem and make the right decisions... Of all the things that would wake me up at 3 in the morning... that's not what worries me the most."

Convective weather

Thunderstorms are caused by "convective activity," in which moist air close to the ground heats up quickly and rises rapidly.

As the air rises, it expands and cools, allowing the moisture in it to condense and form large clouds. More heat means more convective energy, potentially causing instability. In addition, for every 1 degree Celsius increase in the earth's temperature, the amount of moisture the atmosphere can hold increases by about 7%, making heavy rain more likely.

It's unclear whether this means there will actually be more thunderstorms across the UK and Europe, as there are many other variables involved beyond the simple factors of energy and moisture.

Some areas of the world may even see fewer thunderstorms. However, research shows that higher latitudes, particularly in the Northern Hemisphere, will see the greatest increase in favorable storm-forming conditions, and storms that do form are likely to be more violent.

The Met Office said: "While we may not necessarily see more thunderstorms overall, the ones we experience may have a greater impact."

Where possible, pilots avoid flying over convective weather. Although aircraft are designed to handle severe weather, storms can create severe turbulence that not only has the potential to damage the aircraft's structure, but can also cause passengers to be tossed around the cabin if they are not wearing seatbelts.

Hail can also cause serious problems, possibly cracking your windshield or causing engine problems. Therefore, no matter how much inconvenience this may cause to passengers, the crew always puts safety first.

The weather radar on board can help the crew see weather conditions up to 320 nautical miles ahead. They can also use real-time weather forecast resources online.

But thunderstorms move quickly, and Prof Guy Gratton, an aeronautics expert at Cranfield University, said the systems were largely "tactical rather than strategic".

In other words, while these systems allow pilots to see storm clouds on a screen from a relatively short distance and request a diversion, they do not allow them to engage in detailed long-distance planning.

As a result, unplanned diversions often occur later in the flight, which likely means more fuel is consumed.

Andrew Charlton said if delays caused by storms become more common, planes may have to carry more fuel in the future in case there are problems ahead.

"Airplanes are going to have to fly farther, and they're going to have to factor in the hypothesis of flying farther," he said.

Fuel is one of the major costs for airlines, and if fuel bills rise, passengers will inevitably end up paying more, he said.

More severe storms could make air traffic management more difficult in busy areas and could lead to more delays and cancellations.

However, some impacts may be mitigated using new technologies.

For example, both Heathrow and Gatwick have moved away from requiring a fixed minimum distance between arriving aircraft and instead have a system that continuously calculates separation time based on wind speed and aircraft type.

In practice, this means controllers can shorten the distance between landing aircraft, especially in strong winds, allowing aircraft to land faster. NATS said the system has successfully improved landing rates and significantly reduced delays.

However, more severe storms may also bring other impacts. For example, greater rainfall increases the likelihood of flooding. In the worst-case scenario, this can paralyze airport operations, which happened when Dubai International Airport was hit by heavy rain in April 2024.

The airport runway was forced to close for a time, and flights were blocked for two days. More than 1,200 flights have been canceled, affecting tens of thousands of passengers.

But even if the runways and taxiways themselves are clear of water and planes are able to fly normally, passengers may still have difficulty catching their flights if roads, railways or parking lots are flooded.

Protecting against such risks can be expensive. Gatwick suffered severe flooding over the Christmas period in 2013 and has spent tens of millions of pounds on mitigation measures in recent years - but these figures pale in comparison to the estimated investment of more than £2 billion in its current expansion plans.

Clear sky turbulence

Clear-air turbulence is also a real problem. It cannot be seen and is becoming more common as the climate warms.

This situation occurs when there is strong air movement high in the sky, but there are no clouds or other visible signs that pilots can avoid. For passengers, this usually means only a minor bump, but occasionally it can be much more serious.

For example, on March 1, 2023, a Lufthansa flight from Austin, Texas to Frankfurt encountered what the airline described as "brief but severe" turbulence.

People on board described the passengers and crew members being thrown around the cabin when the plane suddenly lost altitude. Seven people were taken to the hospital after the plane made an emergency landing in Washington, D.C.

While this type of turbulence is still rare, it is much more common today than in the past and is likely to increase further.

"You know the forecasts are pretty grim: Severe turbulence on many busy shipping routes around the world could double, triple, or more," said Prof Paul Williams, professor of atmospheric sciences at the University of Reading.

He said incidents over the North Atlantic have increased by 55% since 1979.

Still, he believes solutions can be found, including improved predictions and the use of laser-based technology.

sea level rise

In October 2012, Hurricane Sandy arrived near the East Coast of the United States, triggering storm surges and flooding cities.

That means LaGuardia Airport, built on reclaimed land next to Flushing Bay, looks particularly vulnerable.

Airports that may be most at risk include Amsterdam Schiphol, London City, Bahrain International and Newark Liberty International.

Many airports now have some degree of flood protection in place, especially the larger ones. But halting the rise in flooding risks over the next century will mean significant investment in building flood defences, improving runways and even relocating airports.

According to a report by the University of Newcastle, the associated costs could be as high as $57 billion. These costs are likely to ultimately be borne by taxpayers or travelers.

The aviation industry is often criticized for its contribution to climate change.

It is facing a daunting challenge: on the one hand, it is striving to achieve the goal of carbon neutrality by 2050, and on the other hand, it must cope with the expected doubling of the number of global aircraft in the next 20 years.

Yet it is clear that the impacts of climate change will also be borne by airlines, airports and, inevitably, passengers -

"I think the best thing we can do is mitigate the impact," said Andrew Charlton.

"We need to make sure there is enough space in the terminal to accommodate passengers whose flights are disrupted and delayed, and that there are enough hotel rooms and parking spaces, etc."

But ultimately, he said, "unpleasant moments are going to become more frequent."

He believes passengers will have to accept this as part of flying life.