The heat waves may cause huge problems for aircrafts to take off in coming decades.
Rising temperatures due to global warming will make it difficult for aircrafts to take off in coming decades, according to a study.
During the hottest time of the day, 10 to 30 per cent of fully loaded planes may have to remove some fuel, cargo or passengers, or else wait for cooler hours to fly, researchers said.
"Our results suggest that weight restriction may impose a non-trivial cost on airline and impact aviation operations around the world," said Ethan Coffel from Columbia University in the US.
As air warms, it spreads out, and its density decreases. In thinner air, wings generate less lift as a plane races on a runway, researchers said.
Thus, depending upon the aircraft model, runway length and other factors, at some point a packed plane may be unable to take off safely if the temperature gets too high. Weight must be reduced, or else the flight should be delayed or cancelled, they said.
Average global temperatures have risen up nearly one degree Celsius since 1980, and this would already be affecting flights. Worldwide, average temperatures are expected to rise by another three degrees Celsius by 2100, they said.
However, heat waves will probably become more prevalent, with worldwide annual maximum daily temperatures at airports expected to go up by four to eight degrees Celsius by 2080, according to the study.
It is the heat waves that may cause huge problems.
"This points out to the unexplored risks of changing climate on aviation," said Radley Horton, a climatologist at Columbia University.
"As the world gets more connected and aviation grows, there may be substantial potential for cascading effects, economic and otherwise," said Horton, coauthor of the study published in the journal Climatic Change.
Most studies so far have focused on how aviation may affect global warming (aircraft comprise about 2 per cent of global greenhouse-gas emissions), not vice versa.
However, a handful of studies have warned that warming climate may cause dangerous turbulence along major air routes, and head winds that could increase travelling time.
The new study projects the effects on a wide range of jets at busiest airports in the US, Europe, the Middle East, China and south Asia.
The researchers estimate that if globe-warming emission continues unabated, fuel capacities and payload weights will have to be reduced by as much as four per cent on the hottest days for some aircrafts.
If the world somehow manages to sharply reduce carbon emissions soon, such reductions may amount to as little as 0.5 per cent, they said.
For an average aircraft operating on a day, four per cent weight reduction would mean roughly 12 or 13 fewer passengers less on an average 160-seat craft.
This does not count the major logistical and economic effects of delays and cancellations that can instantly ripple from one air hub to another, said Horton.
Some aircrafts with lower temperature tolerance will worsen the situation more than others, and certain airports with shorter runways, in hotter parts of the world or at high altitudes, where the air is already thin - would suffer more.