Rocket Launch Growth Raises Ozone Layer Concerns
Researchers from the University of Canterbury have issued a warning that the rapid expansion of space travel could pose a significant threat to the Earth’s ozone layer unless coordinated action is taken. While rocket launch emissions remain small compared to other industrial sources, projections indicate they could rival aviation emissions within decades if current growth trends continue. “Many emissions products from rocket launches are ozone-depleting, and the threat to the ozone layer could be significant,” the researchers wrote in the *Journal of the Royal Society of New Zealand*.
The ozone layer, located between 15 and 50 kilometers above the Earth’s surface, acts as a shield against harmful ultraviolet radiation. Decades of chlorofluorocarbon (CFC) use caused severe depletion, most notably over the Antarctic, where a seasonal hole has appeared each spring since 1979. Although international action has led to gradual recovery, scientists caution that rocket emissions could reverse some of these gains.
Rocket launches inject gases and particulate matter directly into the middle and upper atmosphere, where the ozone layer resides. Beyond exhaust products from burning propellants, debris from spacecraft components that burn up upon re-entry releases additional harmful particles. With more than 70 nations now operating space agencies and private ventures multiplying, the scale of launches is accelerating. The so-called “billionaire space race,” driven by Virgin Galactic, Blue Origin, and SpaceX, is pushing both satellite deployment and space tourism. “We’ve seen rocket launches almost doubling in three years and there are missions aiming towards launching up to as many as three rockets a day, which is just unprecedented,” said Dr. Eloise Marais, associate professor in physical geography at University College London.
Smaller commercial operators are also proliferating. India, for example, counted 368 space technology companies by May 2021, reflecting heavy investment in its domestic industry. The global space launch market, valued at nearly $14.5 billion in 2022, is forecast to approach $43 billion by 2030.
There is precedent for atmospheric protection through regulation. The 1987 Montreal Protocol successfully phased out CFCs and related chemicals, earning praise as “the most successful global environmental treaty there’s ever been,” according to Martyn Chipperfield, professor at the University of Leeds and senior researcher at the UK’s National Centre for Earth Observation. A January UN report confirmed that nearly 99 percent of banned ozone-depleting substances have been eliminated, with the ozone hole projected to close within four decades. Without the protocol, two-thirds of the ozone layer might have been destroyed by 2065, doubling harmful solar radiation at the surface.
However, the Montreal Protocol’s success relied on conditions absent in the rocket sector. Industry had viable chemical alternatives, financial support was provided to developing nations, and the treaty’s initial scope allowed for gradual strengthening as science advanced. In contrast, no clear substitute exists for current rocket fuels, and there is little regulatory momentum for a sector still considered niche despite its rapid growth.
Among the pollutants of concern is black carbon soot, released during launches. These particles can persist in the upper atmosphere for up to two and a half years, absorbing solar radiation and warming the surrounding air. “They are very, very efficient at absorbing the sun’s rays, so they warm up the local atmosphere and they offset the energy balance of the earth and impact climate,” Marais explained.
The New Zealand team advocates for global coordination to measure and share data on rocket emissions, integrating ozone impact assessments into design and operational best practices. “Ozone recovery has been a global success story. We want to ensure that future rocket launches continue that sustainable recovery,” said Dr. Laura Revell, associate professor in environmental physics. Chipperfield added, “People do care about the ozone layer. You’d hope there would be some goodwill and action taken like there was last time it was threatened.”
