Extreme heat from the impacts of climate change could cause disruptions to nearly half of the long-haul flights at some of the world's busiest airports by the end of the century, according to researchers at Columbia University. High temperatures can shut down flights in two ways: under extreme temperatures of 49 degrees Celsius (120 Fahrenheit), regional planes can't take off at all, because regional aircraft are only tested up to 47.8°C (118°F); and for a plane to get off the ground, the lift pushing up the plane must be greater than the weight of the plane, warmer air has less lift force, so the warmer the air, the lighter the plane has to be for takeoff. There are only three ways for a plane to lose weight: fuel, cargo and passengers. The study looked at five major aircraft at 19 of the world's busiest airports, and concluded that 10 to 30 percent of flights scheduled for takeoff in the heat of the day will need to reduce their weight by an average of 315.5 Kg (700 pounds), roughly three passengers and their luggage. To find out more go to The impacts of rising temperatures on aircraft takeoff performance.