The Environmental Impacts of Satellites
A landmark U.S. Government Accountability Office report "Large Constellations of Satellites: Mitigating Environmental and Other Effects" documents the potential environmental impacts of satellites and put forward policy options to mitigate the effects.
Although satellites have been used for decades, the numbers are rapidly and exponentially increasing. There were almost 5,500 active satellites in orbit as of spring 2022 and estimates predict the launch of an additional 58,000 by 2030. In the US alone, the FCC has received 70,000 applications since 2016 and granted approximately 10,000. However satellite constellations are not undergoing environmental review.
The GAO report details how the launch, operation, and disposal of an increasing number of satellites could cause or increase several potential effects.
Increase in orbital debris. Debris in space can damage or destroy satellites, affecting commercial services, scientific observation, and national security. Better characterizing debris, increasing adherence to operational guidelines, and removing debris are among the possible mitigations, but achieving these is challenging.
Emissions into the upper atmosphere. Rocket launches and satellite reentries produce particles and gases that can affect atmospheric temperatures and deplete the ozone layer. Limiting the use of rocket engines that produce certain harmful emissions could mitigate the effects. However, the size and significance of these effects are poorly understood due to a lack of observational data, and it is not yet clear if mitigation is warranted.
Disruption of astronomy. Satellites can reflect sunlight and transmit radio signals that obstruct observations of natural phenomena. Satellite operators and astronomers are beginning to explore ways of mitigating these effects with technologies to darken satellites, and with tools to help astronomers avoid or filter out light reflections or radio transmissions. However, the efficacy of these techniques remains in question, and astronomers need more data about the satellites to improve mitigations.
The research study "The proliferation of space objects is a rapidly increasing source of artificial night sky brightness" published in Monthly Notices of the Royal Astronomical Society Letters, finds that objects orbiting Earth elevate the brightness of the night sky by at least 10 percent over natural light levels, exceeding a threshold that astronomers set over 40 years ago for considering a location “light polluted”.
In 2021, the Balance Group filed against the FCC in the DC Circuit regarding the critical need for the FCC to ensure adequate environmental review for satellites stating:
“The Commission’s Order makes clear its intent to play ostrich and hope that SpaceX’s deployment of thousands of satellites will not harm the environment— despite reams of evidence to the contrary. That approach runs directly counter to NEPA’s directive to agencies to pause and evaluate potential risks before acting…”
Additional environmental impacts from satellite proliferation related to human and environmental health include the RF radiation and increased light pollution.
1. Increased radiofrequency radiation (RF) emissions from ground stations, connected devices and transmissions to and from satellites. An evaluation of potential impacts should be included in any evaluation of environmental impacts from satellite networks as research has documented impacts to wildlife and plants.
2. Increased light pollution which impacts astronomy and dark skies. Light pollution impacts nature and ecosystems in a myriad of ways. Studies have found artificial light can disrupt plants and animals life-sustaining behaviors such as reproduction, nourishment, sleep, and protection from predators which have long been dependent on the Earth's natural day/night light rhythms. For example, birds that migrate or hunt at night navigate by moonlight and starlight and artificial light can disrupt their migrations.
As detailed by Dark Skies, scientific evidence suggests that artificial light at night has negative and deadly effects on many creatures, including amphibians, birds, mammals, insects, and plants.
