Climate change may give trans-Atlantic flight passengers a bumpy ride -- study ClimateWire, Tuesday, April 9, 2013 Julia Pyper, E&E reporter Droughts, floods and severe storms fueled by climate change are expected to make life on Earth increasingly uncomfortable, but scientists now warn that rising temperatures could make the skies a rougher place, too. In the first-ever study on the future of aviation turbulence, researchers found that flights over the North Atlantic could get significantly bumpier if carbon dioxide concentrations double from preindustrial levels. "Climate change is not only warming the lower part of the atmosphere, where we all live ... climate change is also changing the basic state of the atmosphere 30,000 feet above our heads, where planes fly," said Paul Williams, lead author of the report and a research scientist at the University of Reading National Centre for Atmospheric Science. "In particular, climate change is accelerating the jet stream," he said. "That is what is making the atmosphere more susceptible to the instability that causes turbulence." Williams and co-author Manoj Joshi of the University of East Anglia focused their report, published yesterday in the journal Nature Climate Change, on the critical North Atlantic corridor, where approximately 600 aircraft travel each day. Using supercomputer simulations, models show that the likelihood of encountering turbulence on flights across the North Atlantic could increase by 40 to 170 percent and will most likely double by midcentury. Turbulence strength could also increase by 10 to 40 percent. "The most important impact people will notice is quite simply the fact that the flight will be bumpier," Williams said. "When you're taking a trans-Atlantic flight, you can expect the seatbelt sign to be switched on twice as much as in the preindustrial climate." 'Clear air turbulence' But turbulence isn't just an annoyance; it increases the number of injuries to passengers and crew, which is some cases are fatal. Turbulence also causes delays and can damage aircraft. The estimated cost to society caused by turbulence is $150 million each year. If that amount goes up significantly, airlines could pass costs on to the customer and ticket prices could soar. The report focused on "clear air" turbulence, which peaks in winter and is problematic because pilots and satellites can't detect it in real time. Unlike turbulence caused by clouds or an airflow shift over a mountain range, clear air turbulence essentially comes out of the blue. Researchers are developing new algorithms to predict where patches of clear air turbulence will crop up, but with moderate success. And even if these models become more accurate, the only way to avoid turbulence is to fly around it, which burns more fuel, ratchets up costs and increases the industry's overall emissions. This research comes as international stakeholders try to negotiate an international agreement to reduce greenhouse gas emissions from the aviation sector in response to a controversial climate law passed by the European Union (ClimateWire, April 1). Aviation currently produces 2 percent of all human-caused emissions, but that amount is forecast to double by 2030. "It's ironic the aviation industry has been recently accused of contributing to climate change," Williams said. "It is kind of poetic justice, in some sense, that the atmosphere is taking its revenge on aviation by making the atmosphere a bumpier place to be."