// The ozone layer is "a fragile shield of gas that protects the Earth from the harmful portion of the sun's rays, helping to sustain life on the planet," according to the United Nations.//
The companies "SpaceX" owned by Elon Musk, "Virgin Atlantic" by Richard Branson, and "Blue Origin" by Jeff Bezos, provide tourism trips to space, for the wealthy who can afford them.
Scientists said that space tourism "could undo progress in addressing the ozone layer", based on research that studied the impact of vehicles leaving Earth and returning to it on the atmosphere, especially its upper parts.
Soot from spacecraft damages the ozone layer
The joint study by University College London, University of Cambridge and MIT found that “soot from spacecraft damages the ozone layer,” especially as it “retains heat 500 times the rate of other sources of soot.”
Scientists studying space travel examined data from 103 rocket launches in 2019, as well as flights made by the three companies mentioned.
They found that "warming from soot doubled after just three years from additional emissions from space tourism, due to rubber added in the fuel, among other reasons." The fact that soot is expelled into the upper atmosphere increases the damage.
The research warned that if space tourism continued with its weekly flights, it would undermine the success of the "Montreal Protocol", an international treaty aimed at protecting the ozone layer, by phasing out the production of a number of substances believed to be responsible for the depletion of the layer.
"The only part of the atmosphere that shows a strong ozone improvement after the Montreal Protocol is the upper stratosphere, and that's exactly where rocket emissions will impact the most," said lead author of the study, Robert Ryan, from the University of California.
"We did not expect to see changes in ozone of this magnitude, which would threaten the progress of ozone recovery," he added.
While the scientists found in the study, published in the Earth's Future Journal, that the current damage is minimal, they stressed the importance of "regulating the growing industry of people who travel to space for tourism purposes, to guard against future problems."