In case it hasn’t caught your attention, Earth’s been going through a lot lately. News about environmental issues is now impossible to ignore. Rising temperatures, plastic pollution, extreme weather events… One might argue that we already have quite enough on our hands on this planet. So much, in fact, that some of the world’s wealthiest are pouring resources into leaving Earth behind to find new planets to call home.
This mission has an ironic cost. A recent study has revealed that the ‘new space age’, with its soaring number of privately funded rocket launches, is ripping open holes in our ozone layer. As billionaires reach for new frontiers in space exploration, it seems we are further undermining the habitability of the only planet we can currently live on.
A new era of privately funded space exploration
According to the study, 2019 saw only 97 orbital space rocket launches globally. By 2024, that number was 258. This number is projected to skyrocket in the coming years. Dr. Laura Revell, who, with her team from the University of Canterbury, led the study into the increasing impact of the rocket industry, explained the reasons behind this shift. She told RESET that “we’re now in the era of ‘New Space’; the recent space activities have shifted from primarily being government-led to the domain of private commercial companies.”
Dr. Sandro Vattioni agrees. The climate scientist and ETH Zurich researcher developed the computer model used in Dr. Revell’s study. He attributed the rise in launches since 2019 to the growth of satellite constellations like Starlink, the satellite internet service developed by Elon Musk’s SpaceX. He explained to RESET that, “low-Earth-orbit satellite constellations… require increasing amounts of space rockets.”
What is the ozone layer and is it related to climate change?
The ozone layer is a layer in the Earth’s stratosphere around 10 kilometres (6.2 miles) from the surface. It contains a high concentration of ozone gas, which absorbs most of the ultraviolet radiation reaching the Earth from the sun.
While both ozone depletion and climate change are major environmental issues, it is important to understand the difference.
According to Dr. Vattioni, a “lack of ozone layer results in more UV-irradiance from the sun. Climate change is due to increased greenhouse gases, which reduce the amount of radiation which would otherwise be radiated off the Earth.”
In short, ozone depletion means less protection from solar UV radiation. This can lead to increased risk of skin cancer, cataracts and weakened immune systems, and negative impacts on plants, animals and all living things on Earth. Climate change, on the other hand, is about the change in global or regional climate patterns, attributed predominantly to the increased levels of atmospheric carbon dioxide from the use of fossil fuels.
A closer look at the impact of rocket launches
Rocket emissions were previously considered small fry when it came to their share of environmental impact. However, a recent rapid acceleration of launch activity has concerned researchers. Using a chemistry climate model co-developed at ETH Zurich and the Physical Meteorological Observatory in Davos (PMOD/WRC), Dr. Revell’s study simulated how projected rocket emissions are expected to affect the ozone layer by 2030.
Emissions from rockets and space debris re-entering the atmosphere pose a unique threat. Unlike emissions from ground-based sources, these pollutants can persist for up to 100 times longer. This is because the upper atmosphere lacks the natural removal processes that clean the air closer to Earth. Gaseous chlorine and soot particles, byproducts of rocket propellants, are a particular concern.
Although most rocket launches occur in the Northern Hemisphere, atmospheric circulation spreads these pollutants globally. These emissions deplete the ozone layer, which is particularly frustrating given the progress we had been making toward repairing it. And, unfortunately, it’s the Southern Hemisphere where the phenomenon of ozone depletion is more pronounced. This means that, once again, it’s the Global South paying the price for the “advancements” of the Global North.
Reversing progress in ozone layer recovery
For several decades, the “hole in the ozone layer” was at the top of headlines. Caused by the emission of long-lived chlorofluorocarbons (CFCs), used as refrigerants in air conditioners, aerosol propellants and foam-blowing agents, these CFCs would decompose in the stratosphere, releasing chlorine products that destroy the ozone layer. This layer protects life on Earth from harmful UV radiation. The Antarctic was particularly susceptible to the impact of this, with a hole forming every spring due to the low stratospheric temperatures.
In conversation with RESET, Dr. Revell reflected that:
“Fortunately, the world came together quickly to address the causes of ozone depletion. The Montreal Protocol has subsequently been strengthened over time, [and] it’s been very successful in reducing emissions of ozone-depleting substances.”
The Montreal Protocol
The Montreal Protocol for Substances that Deplete the Ozone Layer was signed in 1987, successfully banning harmful CFCs.
The Montreal Protocol also had an unexpectedly positive impact on climate change. CFCs are also very strong greenhouse gases with a warming potential thousands of times higher than CO2.
Antarctic ozone hole recovery had already been observed. In fact, it was expected to recover completely by 2066. However, this was before the increase in future rocket emissions caused by Musk and other billionaires.
Revel’s study projected that the acceleration of rocket launch activity could cause global average ozone thickness to decline by almost 0.3 percent year on year, with seasonal reductions of up to four percent over Antarctica. This could delay the ozone layer’s full recovery by years, decades or even permanently.
Who’s going to tell billionaires to come back down to Earth?
To mitigate the environmental impact of the ‘new space age’, scientists and policymakers are calling for action. Dr. Vattioni suggests that using cryogenic fuels, such as liquid oxygen and hydrogen, could substantially reduce damage to the ozone layer. However, he also noted the challenge: “The handling of cryogenic fuels is more challenging than conventional fuels”, due to the costs and infrastructure needed for their handling at very low temperatures.
Ultimately, the team behind the study calls for coordinated action among scientists, policymakers and industry to monitor rocket emissions and to implement necessary regulations, like those that worked so well with the Montreal Protocol. Those pushing for private space exploration simply don’t have the environment in mind, so it’s up to regulators to use this vital research to hold some of the world’s most powerful to account.
