Flights to USA from UK will be longer due to climate change, shorter coming back

Flights to the USA will be longer from the UK and shorter coming back, due to climate change. A flight from London to New York will take up to five minutes longer, while the return trip will be four minutes shorter if carbon dioxide levels double, says a scientist from the University of Reading. His research has been published in the journal Environmental Research Letters.

A stronger jet stream will mean that a London-New York round trip flight will be 1 minute longer overall.

We tend to think that climate change only affects air temperature at ground level. However, what happens at 35,000 feet – an air passenger airplanes’ cruising altitude – is also affected.

Longer westward flights due to climate changeDr. Paul Williams with a New York-bound BA airplane in the background. Flying from London to New York will take longer, but the journey back will be quicker. (Image:

Dr. Paul Williams, a Royal Society University Research Fellow in the Department of Meteorology at the University of Reading, said:

“Transatlantic aircraft may be in the air for an extra 2,000 hours each year, adding $22 million to airline fuel costs, and increasing carbon dioxide emissions by the equivalent of 7,100 British homes.”

“Apart from potentially raising ticket prices, passengers will have a significantly increased chance of being on a record-breakingly fast eastbound flight across the Atlantic. However, they will also have a significantly increased chance of experiencing delayed arrivals in North America.”

Super-busy transatlantic route to get more congested

The transatlantic route is incredibly busy, with approximately 600 flights along the North Atlantic flight corridor each day. With airplanes spending an average of 1 minute longer on a round trip, that busy corridor will become even more congested and more polluting.

The additional 7.2 gallons of jet fuel burnt as a result of changes in the atmosphere would mean 70 million kg of CO2 (carbon dioxide) more being emitted each year.

Dr. Williams said:

“Airlines are constantly monitoring the wind patterns, and using some complicated mathematics to calculate the fastest routes. I have used those same mathematical routing algorithms, but instead of applying them to today’s winds, I used winds generated from climate model simulations.”

“We can crank up the carbon dioxide in the model, look at the effects on the winds, and then see how the flight routes are modified.”

Climate change and the speed of flightsExpect many eastbound flight time records broken and more delays on the journey back.

What’ll happen if CO2 levels double?

Dr. Williams modelled flight times for two decades under a doubling of CO2, comparing them to aircraft flight times calculated from daily winds from a control run of the climate model under conditions that existed before the industrial revolution.

The average tailwind to London at average flight cruising altitudes would be 15% faster from 21.4 m/s to 24.6 m/s, Dr. Williams calculated.

The cruising speed of an airplane would be faster eastbound and slower westbound. In winter, a westbound journey from London to New York would be five minutes longer, while the same eastbound journey would be four minutes shorter. This would mean overall, one minute longer for the round trip.

Dr. Williams explained:

“Car journeys must take place along the network of roads, but plane journeys are obviously not constrained in this way. Planes are free to vary their route from one day to the next.”

“They do this to benefit from wind patterns and reach their destinations as quickly as possible. We know that climate change is altering the winds at high altitudes. However, very little was known about the impacts on flight routes and journey times.”

More eastbound speed records will be broken

The chance of a winter eastbound flight taking less than 5 hours 20 minutes will double, Dr. Williams found, with the probability increasing from 3.5% to 8.1%, his model calculated.

The current record for a passenger (non-Concorde) flight from New York to London stands at 5 hours and 16 minutes, when an unusually fast jet stream helped the plane along on 8th January, 2016.

North Atlantic JetstreamThe North Atlantic jetstream, which moves eastward, will be travelling at a higher speed because of climate change. (Image:

For Westbound crossings, however, the likelihood will double that a flight will last more than seven hours – rising from 8.6% to 15.3%. There will be an increased risk of flight delays.

Dr. Williams said:

“We have previously studied how aircraft turbulence will respond to climate change. We projected large increases in both the amount and strength of clear-air turbulence on transatlantic flights. Looking at the impacts of climate change on flight routes was a natural next step.”

Other studies have looked at what the effects of warmer, less dense air are on lift and take-off weights, and whether it’s worth redirecting airplanes away from ice-supersaturated air to avoid contrail formation and the consequent climate warming.

Dr. Williams said:

“So far, I have looked only at transatlantic flight routes. However, the high-altitude atmospheric winds all across the globe are changing in response to climate change. A future research priority will be to study the impacts on other flight routes.”

In an Abstract in the journal, Dr. Williams concluded:

“Our results provide further evidence of the two-way interaction between aviation and climate change.”

Citation: Transatlantic flight times and climate change,” Paul D Williams. Environmental Research Letters. Published 10 February 2016. DOI:10.1088/1748-9326/11/2/024008.

Video – Climate change makes flight times longer

When we think of global warming, we tend to think of warmer temperatures at ground level, but the air at higher levels also undergoes changes – including where aircraft fly at 35,000 feet.

The atmospheric winds and temperatures at that altitude are very strongly linked. The winds are changing in response to higher temperatures. Dr. Williams explains that his study found that the jetstream along the North Atlantic route will change.