A study on space travel and the atmosphere titled "The Climate and Ozone Impacts of Black Carbon Emissions From Global Rocket Launches" has been published in the Journal of Geophysical Research: Atmospheres.
Researchers from the National Oceanic and Atmospheric Administration (NOAA) suggest that the ever-growing rate of rocket launches may damage the ozone layer and change atmospheric circulation patterns. The NOAA says a "10-fold increase in hydrocarbon fueled launches," which includes kerosene-burning rocket engines that emit black carbon (soot) as exhaust into the stratosphere.
The stratosphere contains the ozone layer, which shields life on Earth from ultraviolet radiation, mitigating skin cancer, weakened immune systems, and disruptions to ecosystems and agriculture that would otherwise arise. Rockets are the only source of pollution above the troposphere, the lowest level of Earth's atmosphere, followed by the stratosphere, which could see 0.5 - 2° Celsius (~1-4° Fahrenheit) increases due to increased pollution from rocket exhaust, and atmospheric circulation slowing by up to 3.5%.
"The bottom line is projected increases in rocket launches could expose people in the Northern Hemisphere to increased harmful UV radiation," said lead author Christopher Maloney, a CIRES research scientist working in NOAA's Chemical Sciences Laboratory.
"Our work emphasizes the importance of ozone depletion caused by soot particles emitted by liquid-fueled rockets. 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," said Martin Ross, a scientist with The Aerospace Corporation.
You can read more from the study here.