Study Warns Climate Change May Shrink Safe Satellite Space Around Earth

A study conducted by scientists at the Massachusetts Institute of Technology (MIT) suggests that continued greenhouse gas emissions from fossil fuels could reduce the usable capacity of low Earth orbit by between one-third and 82 percent by the end of the century. The extent of the impact will depend largely on future levels of carbon pollution.

The findings indicate that global warming may disrupt a natural process that helps clear debris from space, leading to a more congested orbital environment.

Atmospheric Changes Affect Orbital Conditions

While greenhouse gases trap heat in the lower atmosphere, they have the opposite effect at higher altitudes. In the upper atmosphere—where satellites orbit—these gases contribute to cooling, which in turn reduces air density.

This thinning of the atmosphere decreases drag on satellites and space debris. Normally, atmospheric drag gradually pulls debris back toward Earth, where it burns up upon re-entry. However, with less drag, this natural “clean-up” mechanism becomes less effective, allowing debris to accumulate in orbit.

“We depend on the atmosphere to remove debris—there’s no alternative system in place,” said Will Parker, the study’s lead author and an astrodynamics researcher at MIT. He emphasized that millions of fragments of debris already exist in orbit, describing them as persistent waste that cannot easily be managed.

According to Ingrid Cnossen, a space weather expert at the British Antarctic Survey who was not involved in the study, atmospheric density at around 400 kilometers above Earth is already declining by approximately 2 percent per decade. She noted that this trend is expected to accelerate as greenhouse gas emissions continue to rise.

Cnossen said the study’s conclusions are consistent with current scientific understanding, adding that recognizing the orbital consequences of climate change is essential for developing strategies to maintain sustainable use of space.

Growing Risks from Space Debris

Earth’s orbit is already crowded with debris of varying sizes. Millions of fragments measuring at least a few millimeters across—roughly the size of two stacked coins—are traveling at speeds capable of causing damage comparable to a bullet impact.

In addition, tens of thousands of larger objects, about the size of a plum, can collide with the force of a moving vehicle, according to data from The Aerospace Corporation. Much of this debris originates from past satellite collisions and discarded rocket components, with many smaller pieces remaining untracked.

Currently, nearly 12,000 satellites are orbiting Earth, including more than 7,000 in low Earth orbit, based on data from tracking platform Orbiting Now. These satellites play a vital role in communications, navigation, weather prediction, environmental monitoring, and national security.

Researchers warn that assumptions about the vastness of space are no longer valid. “There was once a belief that space was effectively limitless,” Parker said, noting that this mindset has contributed to less responsible management of orbital environments.

Events such as the 2009 collision between two satellites, which generated thousands of debris fragments, have already demonstrated how quickly the situation can worsen. Combined with new evidence showing reduced atmospheric drag, scientists now believe the influence of climate change on orbital conditions is becoming increasingly significant.