Increase in space travel could damage ozone layer and severely disrupt atmosphere, study warns

‘Increases in rocket launches could expose people in the Northern Hemisphere to increased harmful UV radiation’

A projected increase in rocket launches for space missions in the next two decades could damage the ozone layer and change atmospheric wind circulation pattens, according to a new study.

A 10-fold increase in hydrocarbon-fueled launches, plausible within the next two decades based on recent trends in space traffic growth, could damage the protective ozone layer and severely disrupt the atmosphere, said the research, published in the Journal of Geophysical Research Atmospheres.

“We need to learn more about the potential impact of hydrocarbon-burning engines on the stratosphere and on the climate at the surface of the Earth,” Christopher Maloney, study lead author from the Cooperative Institute for Research in Environmental Science, said in a statement.

“With further research, we should be able to better understand the relative impacts of different rocket types on climate and ozone,” Dr Maloney added.

The most damaging emissions from rocket launches are from black carbon, or soot, which absorbs sunlight and retains heat, according to the researchers.

About 1,000 tons of rocket soot exhaust are emitted annually directly into the stratosphere, where a layer of ozone protects all living things on Earth from the Sun’s harmful ultraviolet radiation, which could cause skin cancer and weakened immune systems in humans, they pointed out.

Researchers simulated the impact of about 10,000 metric tons of soot pollution injected into the stratosphere over the northern hemisphere every year for 50 years.

They cautioned that the exact quantity of soot emitted by different hydrocarbon-fueled engines used around the globe was poorly understood.

The simulations revealed the projected level of soot emissions would increase annual temperatures in the stratosphere by 0.5-2C – enough to alter global atmospheric wind circulation patterns.

Researchers said the ozone layer diminished poleward of 30 degrees North – or roughly the latitude of Houston, Texas – in nearly all months of the year with the maximum reduction of the protective layer happening by 4 per cent at the North Pole in June.

This geographical pattern of ozone loss coincides with the distribution of black carbon and the warming associated with it, scientists said.

“The bottom line is projected increases in rocket launches could expose people in the Northern Hemisphere to increased harmful UV radiation,” Dr Maloney explained.

Projecting the impacts of extremely large increase in future space travel using hydrocarbon-fueled engines, researchers found there could be more severe disruptions of atmospheric circulation and climate loss than the 10,000 metric ton case.

“Our work emphasises the importance of ozone depletion caused by soot particles emitted by liquid-fueled rockets,” said Martin Ross, another study co-author.

“These simulations change the long-held belief that spaceflight’s only threat to the ozone layer was from solid-fueled rockets. We’ve shown that particles are where the action is for spaceflight’s impacts,” Dr Ross added.