The Satellite Industry Boom Is Driving an ‘Untested Geoengineering Experiment,’ Scientists Warn

Key Points:

• The commercial satellite industry is rapidly expanding, with SpaceX applying to launch an additional 1 million Starlink satellites beyond the 10,000 already in orbit, raising concerns about overcrowding Earth’s orbit and environmental impacts.
• A new study published in Earth’s Future highlights that black carbon (soot) emissions from rocket launches associated with megaconstellations could account for nearly half of the space sector’s climate impact by 2029, due to their long atmospheric residence and sunlight-blocking effects.
• Researchers used atmospheric chemistry models to project that megaconstellations’ contribution to space sector climate pollution will rise from 35% in 2020 to 42% by 2029, with current growth rates possibly underestimating future impacts.
• While black carbon emissions from rockets have a cooling effect on lower atmospheric layers, this effect is minimal compared to global warming, and the pollution may pose risks similar to controversial geoengineering proposals like stratospheric aerosol injection.
• The study calls for enhanced monitoring and regulation of rocket emissions to mitigate environmental harm, emphasizing the need for policymakers to address the growing pollution from satellite deployments before it causes irreversible damage.