If left unabated, man-made climate change will undoubtedly cause unprecedented environmental disasters, but there is also increasing evidence indicating that our economies will suffer, too. Adding to this, a new study published in Environmental Research Letters reveals that climate change will alter the North Atlantic winter jet stream, leading to longer transatlantic flights. Ultimately, this is estimated to add millions of dollars to airline fuel costs every year.
Jet streams are narrow, fast-flowing air currents within the upper atmosphere that typically flow from west to east. Pilots of passenger planes take advantage of this when flying eastwards by entering the jet stream and significantly reducing their flight time.
These jet streams are fueled by differences in air temperature within the atmosphere. In the winter, the temperature difference between the sunless Arctic and the sun-soaked subtropical regions is far greater than in the summer, which produces a stronger jet stream. Human-induced warming is only intensifying this winter temperature difference, as the subtropical and tropical regions are warming faster than the polar regions.
Dr. Paul Williams, lead author of this new research, wanted to know how this could influence transatlantic flight times. For this study, cutting-edge climate change models were combined with an industry standard flight path algorithm – the type used to calculate the speediest routes across the Atlantic Ocean. The concentration of atmospheric carbon dioxide was doubled (compared to pre-industrial levels), which is the concentration that’s predicted to become a reality at some point this century.
The North Atlantic winter jet stream will only strengthen as climate change intensifies. Gajus/Shutterstock
Remarkably, this had a notable effect: The winter jet stream would be so strong that eastward flights from New York to London would take four minutes fewer to complete. This effect is already being observed in the real world: A flight from New York to London in January last year took a record-setting time of just five hours and 16 minutes, due to an unusually powerful jet stream current.
Flights heading the opposite direction would, as ever, have to try to avoid the jet stream – but under Williams’ simulations, each flight would take five minutes and 18 seconds longer. Overall, the speed boost given to the plane by the jet traveling eastwards is less significant than the speed reduction given to a westward-bound jet. Therefore, under this particular scenario, each round trip will take an extra one minute 18 seconds.
This residual round trip time means that planes will be in the air for an extra 2,000 hours each year. This will burn an extra 32.7 million liters (7.2 million gallons) of jet fuel, at a cost of $22 million a year. Additionally, an extra 72,000 tonnes (about 79,370 tons) of carbon dioxide will be released into the atmosphere each year, contributing to an increased warming effect.
“The aviation industry is facing pressure to reduce its environmental impacts, but this study shows a new way in which aviation is itself susceptible to the effects of climate change,” Dr. Williams said in a statement.