Space tourism erupts: why rocket emissions are so terribly harmful

Now that we can visit every corner of the earth, it should be more exciting: into space. But that space tourism is not only a waste of money, but also bad for the climate. The soot emitted by space rockets damages the ozone layer.

Black carbon, or soot, retains a lot of heat in the higher layers of the atmosphere. Rockets emit a lot of this black carbon, which is bad news for global warming. Scientists from the University of Cambridge (UCL) and the Massachusetts Institute of Technology (MIT) write this in a scientific journal Earth’s Future.

space race
The scientists examined the impact on Earth’s atmosphere and climate under various space tourism scenarios. Billionaires like Elon Musk (SpaceX), Richard Branson (Virgin Galactic) and Jeff Bezos (Blue Origin) are all busy taking tourists into space. The ‘space race’ is in full swing and the consequences for the climate are of secondary importance. Reusable rockets are used, but the emission of harmful substances from combustion engines is enormous.

Warm, black blanket
The research team discovered that the carbon particles released during combustion are almost 500 times better able to retain heat in the atmosphere than soot particles from cars or airplanes. This causes major climate problems when daily or weekly space flights with tourists take place.

This damages the ozone layer in the highest regions of the stratosphere. Holes can form, for example in the spring above the North Pole and the South Pole. The pollutants emitted by the rockets when they leave the atmosphere, but also when they re-enter the atmosphere, are very harmful to the ozone layer. “Greenhouse gas emissions from rocket launches are often compared to harmful emissions from airplanes. We show in our study that this is not true,” says Dr Eloise Marais of UCL Geography. “The black carbon particles that are released during rocket launches have a much greater effect on the climate than during flight movements or transport on Earth. It is important to start a discussion as soon as possible about regulation of this fast growing industry.”

Rocket Launches

The team used data from 103 rocket launches in 2019 on different continents. Both reusable rockets and returning space debris are included in the calculations. Using a chemical 3D model, the impact on the climate and the ozone layer could be calculated. Just three years after the start of space tourism, black carbon emissions have more than doubled. This is alarming, especially since many more and more frequent rocket flights are planned in the near future.

Save the ozone layer (again)
In the 1980s, a major problem with the ozone layer arose. The damage to the protective layer around the earth went so far as to create a hole over Antarctica. Chlorofluorocarbons, or CFCs, were the culprit. They were used as refrigerants in refrigerators and as propellants in aerosol cans. After the Montreal Protocol came into effect in 1987, all CFCs were banned and the ozone layer recovered relatively quickly. This is considered the most successful international climate intervention ever. It seems that we now have to sit around the table again to avert the impending doom.

“The only part of the atmosphere where the percentage of ozone has improved significantly since the Montreal Protocol is the top layer of the stratosphere. That is exactly where the impact of the missiles is greatest. We did not expect such big changes,” explains fellow researcher Dr. Robert Ryan. “There is still a lot of important research to be done. We want to learn more about the size of the space tourism industry and what fuels can be used.”

In conclusion, Ryan says: “This research makes us all think about the implications of space travel. We must regulate space tourism as soon as possible so that the consequences for the climate and the ozone layer do not grow beyond our heads.”