Half of the flights at highly congested airports in Europe will risk delays or cancellations by 2030, according to a Eurocontrol report issued Tuesday. The study, Challenges of Growth, finds demand for flights in Europe will rise from 10 million today to 20.4 million in 2030. Airports’ current plans to meet demand and expand capacity will only be handle 18.1 million of those flights, leaving 2.3 million flights a year or 6,300 flights a day unaccommodated. Airport congestion, as a result, will rise. By 2030, around 20 of the largest airports will be saturated, operating at full capacity, for 8 hours or more a day. About half of every day's flights will pass through one of these saturated airports, according to the report. “Despite the economic downturn and a prospect of slower growth in the future –– because of maturing European markets and higher fuel-related costs –– demand in the longer term is still set to rise substantially,” said David Marsh, manager of forecasting and statistics at Eurocontrol. The report also points to climate change as having an impact on delays, saying bouts of extreme weather will occur more frequently bringing more disruptions to the saturated airports.