by Gavin Haines, The Telegraph, October 4, 2017
It’s an inconvenient truth that jetting off to foreign shores for your holidays directly contributes to the very climate change that, according to some scientists, could have a considerable impact on aviation.
From longer flight times and more expensive plane tickets to an increase in turbulence, here are seven ways a warming planet could impact air travel.
1. More turbulence
Bad news for nervous flyers. Passenger jets will be buffeted by up to three times more turbulence in future decades, according to a new report.
Scientists had already noticed that so-called clear-air turbulence (CAT) was on the rise, but the new study by the University of Reading is the first to come up with a comprehensive mathematical model predicting long-term global conditions. It estimates that by 2050 the rate of inflight injuries will have almost tripled in line with the increased volume of turbulence.
“Air turbulence is increasing across the globe, in all seasons and at multiple cruising altitudes,” said Paul Williams, Professor of Atmospheric Science at Reading, who led the new study. “This problem is only going to worsen as the climate continues to change.”
The research team called for better forecasting systems so passengers can get seated and belted in time. They could soon have their wish. Boeing is preparing to test new laser technology that could allow pilots to detect clear-air turbulence up to 10 miles away.
That’s not far when you consider that the cruising speed of a passenger jet is about 550 mph; it basically gives the pilot 60 seconds to react. However, that’s just enough time to change course slightly or tell the cabin crew to batten down the hatches.
2. More delays and cancellations
In June American Airlines was forced to cancel dozens of flights from Phoenix, Arizona, because it was too hot. With the mercury rising to 120F, the airline said some smaller jets were simply unable to leave the tarmac. Why? Well, hot air is thinner, which makes it harder for planes to generate enough lift to leave the ground.
“When you get in excess of 118F or higher, you’re not able to take off or land,” Ross Feinstein, a spokesman for American Airlines, told the New York Times. Researchers warn disruptions like these are likely to become more common as the planet warms.
3. Longer flights
Climate change is not just making turbulence more common; according to 2015 study, published in the journal Nature Climate Change, rising temperatures are also increasing flight times.
Scientists linked a small increase in return journey times of long-haul flights with an increase in the variation of the jet stream, the high altitude air that flows from west to east.
Just one minute’s extra flight time would mean jets spend approximately 300,000 hours longer per year burning roughly a billion additional gallons of jet fuel, they said, thus adding to the problem.
“Upper level wind circulation patterns are the major factor in influencing flight times,” said Kris Karnauskas, associate scientist at Woods Hole Oceanographic Institution in Massachusetts. “Longer flight times mean increased fuel consumption by airliners. The consequent additional input of CO2 into the atmosphere can feed back and amplify emerging changes in atmospheric circulation.
“We already know that as you add CO2 to the atmosphere and the global mean temperature rises, the wind circulation changes as well – and in less obvious ways.
“The airline industry keeps a close eye on the day-to-day weather patterns, but they don't seem to be concerned with cycles occurring over a year or longer.”
4. More expensive tickets
Damage and delays caused by turbulence is estimated to costs US airlines alone between $150m ($113m) to $500m (£377m) annually. Therefore, if cases of severe air turbulence increase – and if planes have to burn more fuel to counter fiercer winds – passengers could reasonably expect to pay more to fly.
5. More weight restrictions
Until new technology becomes available, there is little pilots can do to avoid lumps and bumps in the skies: clear air turbulence is not visible to the naked eye, isn’t detectable on radar and can’t be accurately forecasted. However, according to Steve Allright, a British Airways pilot, one thing they can do is cruise at higher altitudes, though there are restrictions preventing them from doing so.
“Our endeavours to fly at an altitude that has been reported as smooth may be prevented by several constraints such another aircraft occupying that level, or the weight of the aircraft at that time,” he said.
If planes need to fly higher to avoid turbulence then they would need to be lighter, which means the weight of the aircraft – and possibly passengers' luggage, or even passengers themselves – could invite greater scrutiny.
6. Airport closures
The world's major airports were not built with global warming in mind – they simply needed to be far from big towns and tall mountains, so coastal areas and river deltas were often chosen. These low-lying sites, however, are vulnerable to storm surges and rising sea levels.
Climate change scientists predict that sea levels could rise by as much as six feet this century. But if they rise by just a fraction of this, hundreds of aviation hubs around the world will be threatened. Some countries are taking steps to combat the risk. Norway, for example, has pledged to build all future runways at least 23 feet above sea level.
7. Longer runways
As outlined above, warmer temperatures mean planes have a tougher time taking off and during heatwaves airports with short runways are the first to face problems. Back in 2013, 15 passengers were removed from a Swiss flight to Geneva after the plane was deemed too heavy to take off from London City Airport, whose single 4,900-foot runway is one of the smallest in the country.
Unless airports like London City lengthen their runways, this sort of thing could become a far more regular occurance in future.