Ozone layer is located high in the middle atmosphere and plays a key role in shielding us from the harmful effects of the sun’s UV rays. A recent study has found that the number of rockets being sent into space is increasing quickly, and this could slow down the healing of this important layer. Although the space industry is bringing many new opportunities, it is also causing new environmental issues that we need to address carefully.

Add Asianet Newsable as a Preferred Source

The Space Industry is Growing Fast

In recent years, the night sky has become more crowded with satellites being launched into low Earth orbit. Many companies are sending satellites to improve global internet access, weather forecasting, and more. However, each rocket launch puts harmful substances into the atmosphere, which can damage the ozone layer.

For more than 30 years, scientists have been studying how rocket emissions affect the ozone layer. And until recently, the damage was believed to be relatively small. However, the situation is changing rapidly. In 2019, there were 97 rocket launches worldwide that reached the orbit. By 2024, this number had almost tripled to 258, and it is expected to keep increasing in the coming years.

Why Rocket Emissions Are a Concern

Pollutants from rockets behave differently than those from ground-base sources. Rocket emissions can stay for up to 100 times longer because there are no clouds to remove them in the middle and upper atmosphere. Although most launches take place in the Northern Hemisphere, winds carry these pollutants around the world.

To understand the long-term impact of these emissions, an international research group, including scientists from the University of Canterbury, ETH Zurich, and the Physical Meteorological Observatory in Davos, used advanced computer models to predict how rising rocket activity could affect the ozone layer by 2030.

What Did the Researchers Find

The scientists examined a future scenario where rocket launches could reach around 2.040 per year by 2030, about eight times the number in 2024. In this case, they predicted a global average thinning of the ozone layer by nearly 0.3%, with losses reaching up to 4% over Antarctica, where the ozone hole typically forms each spring.

Under the Montreal Protocol, the ozone layer is still recovering from the damage caused by chemicals called chlorofluorocarbons (CFCs), which were banned in 1989. Today, the ozone layer is about 2% thinner than it was before industrial pollution began, and scientists estimate it will fully recover by around 2066.

Experts say that rocket emissions, which are currently not regulated, could slow the ozone layer’s recovery by years or even decades.

Are All Rockets Harmful?

The main sources of damage are gases containing chlorine and soot particles. Chlorine is especially harmful because it reacts with ozone and breaks it down. Soot particles also warm the middle atmosphere, which speeds up chemical reactions that destroy ozone.

Most rockets create soot, but only a few use cleaner fuels like liquid oxygen and hydrogen, which do not harm the ozone. These cryogenic fuels are difficult to work with, so only about 6% of rockets currently use them.

What About Satellites Coming Back to Earth?

When the satellites and space debris burn up and re-enter the atmosphere, they release pollutants like metal particles and nitrogen oxides, which could also damage the ozone layer.

Nitrogen oxides can destroy ozone, and metal particles might help form clouds that increase ozone loss, especially over the poles. Scientists say that with more satellites being launched, the number of re-entries will likely increase, adding more harm to the ozone layer.

What Needs to Be Done?

While these challenges are concerning, there is still hope. The space industry can take steps to avoid causing significant harm to the ozone layer. This includes monitoring rocket emissions, reducing the use of chlorine and soot-producing fuels, promoting cleaner propulsion systems like cryogenic engines, and developing rules and regulations to limit the impact.

Success will require cooperation between policymakers and the space industry. The Montreal Protocol showed that global collaboration can effectively address major environmental threats. As space activity continues to grow rapidly, similar worldwide efforts are needed to protect the ozone layer, Earth's most important natural shield.