Climate change 'will slow flights from London to New York'

New research finds that increasing carbon dioxide in atmosphere will accelerate jet stream, speeding up transatlantic flights to London but slowing journeys in the opposition direction - adding 2000 hours in the air overall

Rob Crilly | Daily Telegraph | 10 Feb 2016

Passengers on transatlantic flights will find themselves spending more time in the air because of climate change, according to a new study by scientists at the University of Reading.

They found that doubling the amount of carbon dioxide in the atmosphere would accelerate the jet stream in winter, shortening the length of eastbound journeys but slowing westbound journeys.

However, the changes do not cancel each other out leaving an overall increase in journey time if nothing is done to reduce greenhouse gas emissions.

Passengers may already be seeing some of the effects. Last year, a British Airways Boeing 777 reported travelling at velocities approaching the speed of sound during a New York to London crossing which took only five hours and 16 minutes - beating its scheduled time by an hour and a half.

Inspired by reading The Telegraph's story about the feat, Dr Paul Williams, an atmospheric scientist at the University of Reading, set out to forecast future impacts of climate change on the route.

He fed wind data from climate models into algorithms used by flight planners to determine routes and calculated that transatlantic aircraft will spend an extra 2,000 hours in the air every year, adding millions of dollars to airline fuel costs and increasing the risk of delays.

"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," he said.

"The bad news for passengers is that westbound flights will be battling against stronger headwinds. The good news is that eastbound flights will be boosted by stronger tailwinds, but not enough to compensate for the longer westbound journeys. The net result is that roundtrip journeys will significantly lengthen.

"This effect will increase the fuel costs to airlines, potentially raising ticket prices, and it will worsen the environmental impacts of aviation."

Jet stream winds between Europe and North America are predicted to become 15% faster in winter (with similar increases in other seasons), increasing from 48 to 55mph.

The result is that flights from New York's JFK airport to Heathrow will be twice as likely to take less than five hours and 20 minutes. In the opposite direction, flights will become twice as likely to take more than seven hours.

Last year, two flights from London were forced to make unscheduled refuelling stops in Maine after battling headwinds across the Atlantic.

The North Atlantic flight corridor is one of the world's busiest, with about 600 crossings a day.

So that extra time converts into an extra $22 million of fuel burned each year, emitting 70 million kg more carbon dioxide - equal to the annual emissions of 7,100 British homes - according to the research paper published in Environmental Research Letters.

Similar results may be seen elsewhere in the world where air corridors use the northern or southern hemisphere jet streams, added Dr Williams.

His earlier research found climate change is likely to cause more clear-air turbulence.