(NEW YORK) — Climate change could threaten the future use of satellites and significantly reduce the number of spacecraft that can safety orbit Earth, according to new research.
Global warming is causing space debris to linger above the planet for longer periods of time, leaving less space for functioning satellites and posing a growing problem for the long-term use of Earth’s orbital space, a study published Monday in Nature Sustainability found.
While increasing levels of human-caused greenhouse gases cause a warming effect on Earth’s lower atmosphere, it has an opposite impact on the upper atmosphere, William Parker, a PhD candidate at the Massachusetts Institute of Technology’s Department of Aeronautics and Astronautics and author of the study, told ABC News.
The radiation from greenhouse gas emissions is also causing Earth’s upper atmosphere to cool, according to Parker.
“We’re basically losing energy in the upper atmosphere, and that causes the cooling and the contraction,” he said.
The cooling effect has created a long-term contraction of the upper atmosphere — similar to how a balloon shrinks in a freezer, Parker said. Typically, the upper atmosphere slowly pulls space debris out of Earth’s lower orbit. But the cooling and contracting effect is causing less drag in the thermosphere, causing the space junk to linger longer, he explained.
The debris also poses a threat to every active satellite, Parker added.
“As long as it’s up there, it’s a persistent hazard,” Parker said.
There is currently “tons of debris” in Earth’s low orbit, said Parker, who has been researching the dynamics of spacecraft close to the Earth. That debris has been created by collisions, explosions between satellites and anti-satellite weapons tests that have occurred over the last several decades. Thousands of pieces of space debris are in orbit, but the number grows to the millions when counting smaller fragments measuring less than 10 centimeters, Parker said.
The longer the space debris remains in the upper atmosphere, the more crowded the space becomes, Parker said. And Earth’s orbital space is limited.
“It’s a complicated operating environment today,” Parker said.
Rising greenhouse gas emissions could reduce the total number of satellites that can safely orbit Earth by up to 66% by the end of the century under a high emissions scenario — equivalent to 25 million to 40 million satellites, according to the researchers.
Entities that operate in space may need to increasingly conduct active debris removal, which can cost tens of millions of dollars for a single operation and involve sending up a satellite to remove debris, Parker said.
In 2022, the U.S. Federal Communications Commission passed a rule that every satellite that’s launched from the U.S. has to be able to remove itself from orbit five years after the end of its mission.
A drastic reduction in greenhouse gas emissions will be necessary to prevent further complications with space operations, Parker said.
“An upside there is that reducing greenhouse gas emissions doesn’t just help us on Earth, it also has the potential to protect us from long-term sustainability issues in space,” he noted.
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