Transatlantic flights could be more of a bumpy ride in the future because climate change has a greater effect on the jet stream than previously thought.
Jet streams are narrow currents of air that carry warm and cold air across the planet found at high altitudes at speeds of up to 250mph (400kmph).
Researchers found that the jet stream has become 15 per cent more sheared in the upper atmosphere over the North Atlantic since satellites began observing it in 1979.
The greater the shear - the difference in wind speed or direction over a relatively short distance - found in jet streams, the greater the turbulence planes encounter.
Scientists claim that human-induced climate change will make severe turbulence up to three times more common by 2050-80.
Vertical wind shear - the increase in wind speed at higher altitudes - causes invisible clear-air turbulence.
This can be severe enough to throw passengers out of their seats, terrifying nervous flyers and injuring hundreds of passengers and flight attendants every year.
Temperature difference between Earth's poles and the equator is narrowing at ground level because of climate change.
The new study conducted by experts from Reading University shows for the first time that the opposite is happening at around 34,000 feet (6.4 miles / 10.3 km) - a typical cruising altitude for transatlantic flights.
'Over the last four decades, temperatures have risen most rapidly over the Arctic, whilst in the stratosphere - around 12 km (7.5 miles) above the surface - they have cooled,' lead author Simon Lee, a PhD student in meteorology at the university said in a written statement.
'This has created a tug-of-war effect, where surface temperature changes act to slow the jet down, while temperature changes higher up act to speed it up.
'Our study shows these opposing effects currently balance out, meaning the speed of the jet stream has not changed.
'However, we looked for the first time at the wind shear, where significant change has previously gone unnoticed.
'This strengthens previous projections for increased clear-air turbulence, as we can see an increase in one of the driving forces has happened already.
'This has serious implications for airlines, as passengers and crew would face a bigger risk of injury.'
Tens of thousands of planes encounter severe turbulence every year, with an estimated cost to the global aviation sector of up to £826 million ($1 billion) each year.
This comes from flight delays, injuries to cabin crew and passengers, and structural damage to aircraft.
Experts from the university are now working with aircraft engineers to make sure that the next generation of planes are fit for a warmer and bumpier airspace.
'Indications of a stronger jet stream in the future suggest the upper-level tug will eventually win out,' added Mr Lee.
'This would also affect airlines by increasing flight times from Europe towards the US and speeding up flights the other way.'
The full findings of the study were published in the journal Nature.