A couple of days ago I was flying back from New York to London and as soon as we took off, I heard the magical phrase: “Please keep your seatbelt fastened during the whole flight. We expect a bumpy ride”. The pilot was right – it was so bad that I couldn’t sleep, watch any movies, not to mention complete any work I had planned to do. To be honest, I was sure we would crash, so I’m happy just because I can write this blog post today.
This adventurous trip reminded me of one of seminars I attended during my first year of Mathematics of Planet Earth program. I should have paid more attention to Dr Paul Williams from the University of Reading, who claimed that due to climate change we can expect more turbulence while flying over the Atlantic Ocean.
Most of us associate global warming with increased temperatures on the ground. However, as the above mentioned atmospheric scientist reported, it also makes the jet stream even stronger.
According to the Met Office, jet streams are ribbons of strong winds around 9 to 16 km above the Earth’s surface (so right below the tropopause). They move weather systems with the speed of up to 200 mph. The temperature difference between tropical and polar air masses is their main cause. Meteorologists care about jet streams a lot because waves and ripples formed along them can dramatically deepen Atlantic depressions while moving towards Europe.
Jet streams make flights from America to Europe faster than westbound journeys. Indeed, my flight ticket to the USA states that the journey lasted 8 hours 27 minutes while on the way back it took 7 hours 10 minutes. The pilot could have done even better, because the record on this route belongs to Boeing 777 operated by British Airways that in January 2015 landed at Heathrow after 5 hours and 16 minutes. They took advantage of the jet stream that brought heavy rainfalls and winds to the UK.
While jet streams work in favour of passengers travelling to the capital of the UK, they also make flights towards Big Apple longer. Especially because these winds are getting stronger due to climate change causing increased differences between temperatures of troposphere and stratosphere. The stronger the jet streams become, the shorter the eastbound and the longer the westbound flights. The problem is that quicker journeys from America won’t compensate for the increased flight time against the wind. Williams estimates that each airplane flying over Atlantic will spend extra 2000 hours in the air, which means millions of gallons of jet fuel burnt. This will lead to the emission of 70 million kilograms of carbon dioxide, about as much as annual emission from 7100 average British households. It’s a vicious cycle: climate change causes more carbon dioxide burnt, which causes climate change, which causes…
The increased time spent in the air isn’t the only unfavourable effect of the climate change on aviation. Research shows that passengers should expect more turbulence incidents. Every year hundreds of people suffer injuries due to unexpected “bumps” during the flight. In 2016 videos such as the one taken on the flight from Abu Dhabi to Jakarta went viral. During this flight turbulence was so strong that 31 passengers and crew members had to seek medical help after landing in Indonesia. Such incidents make me think that my flight wasn’t as traumatic as I believed!
Jet stream is one of the common causes of the clear-air turbulence, a turbulence not associated with a cloud. This type of turbulence can be dangerous because radars aren’t able to detect it; this is why it’s usually unexpected not only forpassengers, but also pilots. And Dr Paul Williams with Dr Manoj Joshi (University of East Anglia) pointed out that we have to prepare for more such surprises as the level of carbon dioxide in the atmosphere increases.
Apart from obvious discomfort and dangers, increased turbulence leads also to considerable financial loss. Williams’ report states that airlines spend millions of dollars to repair damage caused by turbulence. Moreover, sometimes airlines have to find longer routes avoiding notoriously turbulent areas, which leads to even more money spent and more pollutants emitted. For us, passengers, it means delays as well as longer flights.
So fasten your seat belts – just in case. And have a safe flight!