Climate scientists predict that sea levels could rise by as much as six or seven feet this century, and aviation experts say that even a much smaller rise could lead to more flooding at runways or terminals.
Preliminary studies indicate that dozens of airports are at risk. A 2009 report by Eurocontrol, a Brussels-based agency that coordinates air traffic management across Europe, estimated that more than 30 major European airports sat on coastlines or within river floodplains.
Some airports are already taking such warnings to heart.
In Hong Kong, officials say that a project to build a third airport runway on soon-to-be reclaimed land was influenced by climate and sea-level projections made in 2014 by the Intergovernmental Panel on Climate Change. They say the $18 billion runway will have a sea wall that stands at least 21 feet above the waterline and can withstand 100-year storms, as well as a drainage system that is designed to handle rare floods.
In Norway, about 20 of the country’s 45 state-run airports are “quite exposed” to potential sea level rise, said Olav Mosvold Larsen, a climate change adviser at Avinor, the state-run airport operator. Avinor has decided to build all future runways at least 23 feet above sea level.
Sea level rise and storm surges have a “somewhat-nearer-term flavor” for airports than other climate-related risks, such as rising temperatures, said Terence R. Thompson, a senior fellow at the Logistics Management Institute in Virginia who studies links between aviation and climate change.
“You’ve got this complex, multisegment industrial site, and it’s not just ‘Does the runway go underwater?’” he said. For example, the flooding of a taxiway could force pilots to take longer taxi routes from terminals to runways, causing delays at one airport that ripple across many others, he said.
Climate scientists predict a global increase this century in the annual number of hot days and heat waves, and some airport planners worry that climate change could push airport infrastructure to the limits of its operating capacity.
Runways in northern Canada have already been damaged by thawing permafrost, for example, leading officials to commission permafrost studies ahead of a recent $240 million renovation of Iqaluit International Airport in the Canadian Arctic.
Concrete runway slabs at other airports may buckle from extreme heat, as similar slabs occasionally do on highways, and there is “serious concern” that asphalt on aprons and parking areas could melt, said Herbert Pümpel, a co-chairman of the World Meteorological Organization’s Expert Team on Aviation, Science and Climate.
Then there are concerns about aircraft.
A plane’s maximum operating temperature depends on a variety of factors, including airport elevation. But as temperatures climb far above 100 degrees Fahrenheit, airlines can begin suspending operations for certain types of planes, as American Airlines did in June when daytime highs in Phoenix climbed to about 120 degrees.
Captain Rajeev Bajpai, Air India’s general manager of operations for the country’s western region, said that extreme heat was already an aviation problem in notoriously hot countries like Kuwait, where planes can be grounded on summer days because their electronics automatically shut down.
“You can’t even get the flight going in the sense that you can’t even prepare the cockpit,” he said.