Scientists Warn: Greenhouse Emissions Could Push Low Earth Orbit to the Brink of Collapse | The Daily Galaxy --Great Discoveries Channel
Lydia Amazouz
Published on March 11, 2025
The growing release of greenhouse gases into the atmosphere could pose a serious threat to the future of space operations, especially in low Earth orbit (LEO). A recent study published in Nature explores the potential consequences of increased emissions on the capacity of LEO to support satellite operations. The study highlights the risks posed by space junk, climate change, and orbital debris accumulation, which, together, could disrupt one of humanity’s most valuable technological frontiers.
The research reveals that emissions have a direct effect on the thermosphere, a layer of Earth’s atmosphere located between altitudes of 85 to 600 kilometers. This region plays a critical role in satellite drag, which can either slow satellites down and cause them to re-enter Earth’s atmosphere or keep them in orbit. As emissions increase, the thermosphere shrinks, leading to reduced drag on satellites and increasing the longevity of space debris. This, in turn, exacerbates the issue of overcrowding in low Earth orbit, making it harder for new satellites to operate safely.
How Greenhouse Emissions Affect Satellite Operations
The new study shows that the effects of greenhouse gas emissions could drastically reduce the space available for satellite operations in low Earth orbit by the end of the century. The researchers modeled the situation under different emissions scenarios, and the results were alarming: By 2100, under moderate to high emissions scenarios, the capacity for satellites in altitudes ranging from 400 to 1,000 kilometers could be reduced by up to 82%. This scenario could limit the number of satellites that can operate in LEO, especially during solar minimum periods.
Greenhouse gases, primarily carbon dioxide, influence the thermosphere’s density, which plays a key role in atmospheric drag. As the thermosphere becomes less dense due to the effects of greenhouse emissions, drag on satellites decreases, allowing them to remain in orbit much longer than they otherwise would. While this may seem beneficial for operational satellites, it poses significant problems for defunct ones.
Satellites are designed to gradually lose altitude due to drag, eventually re-entering Earth’s atmosphere, where they burn up. However, as drag decreases, this natural process takes longer, leaving defunct satellites lingering in orbit and contributing to the growing debris problem. This makes the environment in low Earth orbit more hazardous, complicating the operation of new satellites and increasing the risk of collisions. As the study’s lead author, William Parker from MIT, emphasizes:
“Climate change and orbital debris accumulation are two pressing issues of inextricable global concern requiring unified action.”
The Unpredictable Future of Low Earth Orbit
The study highlights the fragility of low Earth orbit and the risks posed by increased emissions. As more satellites are launched into orbit, the problem of overcrowding becomes more serious. Currently, about 11,901 satellites are operational in orbit, with an additional 20,000 pieces of space debris. While we are far from reaching the critical point where Kessler syndrome occurs, scientists warn that continued emissions could push us dangerously close to that threshold.
The expansion of satellite constellations, such as those deployed by companies like SpaceX, adds to the challenge of managing space debris and maintaining a safe environment in low Earth orbit. Even as technological advances improve our ability to track and monitor debris, the sheer volume of objects in orbit makes collision events increasingly likely. These collisions could result in more debris, creating an uncontrollable cycle of space junk accumulation that would threaten future space operations.
As Parker and his colleagues argue in the study:
“Understanding and respecting the influence that the natural environment has on our collective ability to operate in low Earth orbit is critical to preventing the exploitation of this regime and protecting it for future generations.”