Despite the encouraging news coming from the United Nations saying the ozone’s layer is on track to heal by 2040, rocket launches deploying mega-constellations of satellites continue posing a threat to the Earth’s protective layer.
1. Satellite mega-constellations
Orbiting around Earth today are 7,790 intact satellites, of which 4,800 are functioning, according to the European Space Agency (ESA). By 2030, this number may rise to a staggering 58,000, based on an assessment by the US Government Accountability Office (GAO). In 2021 alone, 146 orbital launches put 1,800 satellites into space and another 143 sub-orbital launches of rockets to over 80 kilometers in altitude were registered. This represents a total of 289 high-altitude launches for the year, or almost one every day.
Most of the future satellites to orbit Earth will belong to mega-constellation operators such as SpaceX’s Starlink, OneWeb or Amazon’s Kuiper. The majority of these satellites will reside in Earth’s low orbit, the region of space below 2,000 kilometers (1,200 miles), and will be regularly replaced by newer, more advanced models.
2. Space junk
This means that within a decade, huge amounts of space junk will be orbiting the Earth as gravity drags the old unwanted satellites back to the planet. Since 1957, there have been more than 630 breakups, explosions, collisions, and other satellite-destroying events. This has resulted in the creation of more than 9,700 tons of space debris. Satellites are made of metals such as aluminum and titanium and contain other potentially toxic substances. Scientists worry that as these satellites burn, they may release harmful chemicals that could damage the recovering ozone layer.
3. Ozone’s layer
The years 2020 and 2021 witnessed two of the largest Antarctic ozone holes since measurements began in 1979. In a 2020 paper titled “The environmental impact of emissions from space launches: A comprehensive review”, Jessica Dallas and her colleagues at the University of New South Wales wrote that “ozone depletion is one of the largest environmental concerns surrounding rocket launches from Earth.”
Arthur Firstenberg, an American author and activist on electromagnetic radiation and health says that “everyone is still blaming chlorofluorocarbons (CFCs), but nobody is looking at rocket launches, of which there were more in 2020 and 2021 than in any previous year.”
In the 1980s, alarm over the loss of ozone led to the implementation of the Montreal Protocol, which took place in 1989. However, the progress achieved by such implementation is now being threatened by the very foundations of space exploration.