Study says climate change will even make Earth's orbit a mess

Climate Change Threatens to Worsen Space Debris Problem, Study Finds

Climate change is already wreaking havoc on Earth, but a new study suggests it will soon create problems in space as well.

Researchers at MIT have calculated that continued global warming, driven by the burning of coal, oil, and gas, could shrink the available space for satellites in low Earth orbit by anywhere from one-third to 82% by the end of the century. The extent of this impact depends on the amount of carbon pollution released. As climate change disrupts natural atmospheric processes, space is expected to become increasingly cluttered with debris.

One major consequence of climate change is that while it warms the air near Earth's surface, it simultaneously cools the upper atmosphere, where satellites operate in low Earth orbit. This cooling reduces atmospheric density, decreasing the natural drag that helps remove space debris.

Under normal conditions, this atmospheric drag pulls space junk down to Earth, where it burns up upon reentry. However, with a cooler and less dense upper atmosphere, that self-cleaning mechanism weakens, allowing more debris to accumulate. The findings, published in the journal Nature Sustainability, suggest that this could lead to a significantly more congested orbital environment.

“We rely on the atmosphere to clean up our debris. There’s no other way to remove it,” said lead author Will Parker, an astrodynamics researcher at MIT. “It’s trash. It’s garbage. And there are millions of pieces of it.”

Currently, millions of debris fragments larger than 3 millimeters (about the width of two stacked pennies) are orbiting Earth, moving with the energy of bullets. Tens of thousands of larger pieces, roughly the size of a plum, can strike with the force of a crashing bus, according to The Aerospace Corporation, which monitors space debris. Much of this junk comes from past satellite collisions and rocket fragments, with many pieces too small to be tracked.

As of now, 11,905 satellites are orbiting Earth, with 7,356 positioned in low Earth orbit, according to tracking website Orbiting Now. These satellites play a crucial role in communications, navigation, weather forecasting, and monitoring environmental and national security issues.

“There used to be this belief that space is vast, and we didn’t need to worry about being responsible stewards of the environment because space seemed unlimited,” Parker said.

However, that perspective changed in 2009 when a satellite collision produced thousands of additional debris fragments. NASA data has also confirmed a measurable reduction in atmospheric drag, highlighting the significant role climate change plays in exacerbating the problem.

The density of the upper atmosphere at approximately 250 miles (400 kilometers) above Earth is decreasing by about 2% per decade, and this trend is expected to accelerate as greenhouse gas emissions continue, said Ingrid Cnossen, a space weather scientist at the British Antarctic Survey who was not involved in the study.

In an email, Cnossen described the study’s conclusions as “perfectly logical,” emphasizing the need for scientists and policymakers to consider climate change’s effects on space debris. “We must take appropriate measures to ensure the long-term sustainability of Earth’s orbit,” she said.