operation events are going to be more likely to occur as the climate warms, more heat in the atmosphere, thermodynamics 101, we re going to have more thunderstorms. reporter: atmospheric researchers agree, and say high altitude turbulence has also grown stronger over the decades, sending service carts, food and drinks and passengers flying. do we have any trained medical personnel? do we have any doctors, nurses? reporter: it already happens 5,500 time each year, and projected to grow two to three times worse in the years to come what we can confidently say is climate change is increasing the amount of clear-air turbulence in the atmosphere. reporter: while airlines can warn pilots of turbulence ahead, violent thunderstorms remain the biggest threat the number one cause of delays and cancellations is weather. reporter: the ntsb says the increasingly volatile weather and turbulence underscore the need for passengers to wear the