Companies are launching satellites into space at a record pace. SpaceX, known for having the largest satellite constellation, recently sought permission to add 1 million more Starlink satellites to the 10,000 already in orbit.
Scientists are raising concerns about these megaconstellations. A recent study published in the journal Earth’s Future suggests that they could be affecting not only our view of the stars but also our climate. The study shows that pollution from rocket launches, particularly black carbon (or soot), could contribute significantly to climate change—almost half of the space sector’s environmental impact by 2030.
Eloise Marais, a professor at University College London, describes this growing pollution as a “geoengineering experiment” with potentially unintended consequences. Black carbon particles released high above the Earth can block sunlight, cooling parts of the atmosphere. Although current emissions from launches are low compared to proposed geoengineering methods, this could change if the industry continues to grow unchecked.
The commercial satellite industry is booming. According to the latest State of the Satellite Industry report, released by the Satellite Industry Association, revenue from commercial satellites made up 71% of the global space market in 2025. In 2024, 296 rocket launches put a remarkable 4,434 new satellites into orbit—a 65% increase from the previous year.
Given this rapid growth, researchers like Marais are working to understand the environmental impact of satellite emissions. They tracked air pollution data from 2020 to 2022 to project future emissions. Their analysis indicates that by 2029, megaconstellations could account for 42% of the climate impact from the space sector, up from 35% in 2020.
Marais notes that while more data would improve the accuracy of these predictions, the trend shows concerning growth.
The study examined pollutants from rocket launches and decommissioned satellites. Surprisingly, soot from rocket launches has a more substantial cooling effect than soot from ground sources, lingering in the atmosphere longer. However, this cooling effect is still small when compared to the overall impact of greenhouse gas emissions.
Interestingly, the research also looked at whether these rocket emissions could harm the ozone layer. It appears that most rockets do not release harmful chlorine compounds that could deplete ozone. However, some companies plan to use propellants that might include chlorine, raising concerns for the future.
Marais emphasizes the need for better monitoring of rocket pollution. Her team is developing an online emissions tracker and new methods to observe rocket launches from space. They hope their findings will prompt policymakers to create regulations that protect the environment, so future generations won’t face the consequences of our actions today.
The implications of space pollution are significant. As more companies enter this rapidly expanding industry, the focus on eco-friendly practices is vital. Only by understanding and addressing these challenges can we ensure a sustainable future—not just on Earth, but in our cosmic endeavors as well.
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Air pollution,Climate change,geoengineering,Global warming
