Fasten your seatbelts: turbulence ahead, warn scientists Algarve Resident, 26 April 2013 The chances of encountering significant clear-air turbulence during flights between Europe and North America will increase by between 40 and 170% by 2050 as a result of climate change, according to scientists from the UK-based University of Reading and the University of East Anglia (UEA). The conclusions are based on the results of analysing supercomputer simulations of the atmospheric jet stream over the North Atlantic Ocean and have been published in the journal Nature Climate Change. The study, 'Intensification of winter transatlantic aviation turbulence in response to climate change', is the first to examine the future of aviation turbulence, and researchers suggest that the most likely outcome is a doubling of the airspace containing significant turbulence at any time. In addition, they believe the average intensity of turbulence will increase by between 10% and 40%. Clear-air turbulence refers to severely turbulent movement of air masses in the absence of any visual indicators such as clouds, and is most frequently encountered in the regions of the jet streams. These high velocity currents occur at an altitude of around 17,000 metres, and are particularly intense during the winter months. "Our research focussed on clear-air turbulence in winter," explained the report's co-author Dr Manoj Joshi, from UEA's School of Environmental Sciences. "This is especially problematic to airliners, because clear-air turbulence is invisible to pilots and satellites, and winter is when it peaks." Dr Paul Williams, a Royal Society University Research Fellow at the University of Reading in the Department of Meteorology and the National Centre for Atmospheric Science, who led the study, added: "Aviation is partly responsible for changing the climate [due to carbon emissions] in the first place. It is ironic that the climate looks set to exact its revenge by creating a more turbulent atmosphere for flying." Upper-level winds in the atmosphere are being modified by climate change, and turbulence is sensitive to these winds, noted Dr Williams, speaking to US-based social issues website TakePart. His observations were also highlighted in the UK's The Guardian newspaper: "Climate change is heating the Arctic faster than lower latitudes, because of the rapid loss of reflective sea ice, so the temperature difference is growing. That leads to stronger jet streams and greater turbulence." Air turbulence can be hazardous to the comfort, and even safety, of air travel. Each year hundreds of passengers and aircrew are injured as a result of this unpredictable phenomenon. It also causes delays and damage to planes with a total annual cost of approximately 140 million euros. "This research shows that climate change will cause more frequent air turbulence and more bumpy flights in just a few decades," warned Dr Joshi. "Flights may need to be re-routed more frequently in future to avoid turbulence," he suggested. "This would increase fuel consumption and pollution, cause more airport delays and push up ticket prices." Dr Williams added: "Most air passengers will have experienced the uncomfortable feeling of mid-flight air turbulence. Our research suggests that we'll be seeing the 'fasten seatbelts' sign turned on more often in the decades ahead."