Study shows how rocket launches pollute the atmosphere

Atmospheric scientist Laura Revell, with the University of Canterbury in New Zealand, presented research showing that rocket exhaust in the atmosphere can erase some of the hard-won gains in mitigating ozone depletion.

In a high-growth scenario for the space industry, there could be as many as 2,000 launches per year, which her modeling shows could result in about 3 percent ozone loss, equal to the atmospheric impacts of a bad wildfire season in Australia. She said most of the damage comes from chlorine-rich solid rocket fuels and black carbon in the plumes.

The black carbon could also warm parts of the stratosphere by about half-a-degree Celsius as it absorbs sunlight. That heats the surrounding air and can shift winds that steer storms and areas of precipitation.

“This is probably not a fuel type that we want to start using in massive quantities in the future,” she added.

Researchers at the conference estimated that in the past five years, the mass of human‑made material injected into the upper atmosphere by re‑entries has doubled to nearly a kiloton a year. For some metals like lithium, the amount is already much larger than that contributed by disintegrating meteors.

In the emerging field of space sustainability science, researchers say orbital space and near-space should be considered part of the global environment. A 2022 journal article co-authored by Moriba Jah, a professor of aerospace engineering and engineering mechanics at the University of Texas at Austin, argued that the upper reaches of the atmosphere are experiencing increased impacts from human activities.

The expanding commercial use of what appears to be a free resource is actually shifting its real costs onto others, the article noted.

At last year’s European Geosciences Union conference, Leonard Schulz, who studies space pollution at the Technical University Braunschweig in Germany, said, “If you put large amounts of catalytic metals in the atmosphere, I immediately think about geoengineering.”

There may not be time to wait for more scientific certainty, Schulz said: “In 10 years, it might be too late to do anything about it.”

Bob Berwyn is an Austria-based reporter who has covered climate science and international climate policy for more than a decade. Previously, he reported on the environment, endangered species and public lands for several Colorado newspapers, and also worked as editor and assistant editor at community newspapers in the Colorado Rockies.

This story originally appeared on Inside Climate News.