Satellites and space debris disrupted by climate change

Climate change from greenhouse gas emissions might threaten spacecraft as well as people, a scientists suggested on Sunday, providing direct evidence that carbon dioxide from human activity is affecting the outermost portion of the Earth's atmosphere.

In a study published in the journal Nature Geoscience, a research team led by John Emmert of the U.S. Naval Research Laboratory's Space Science Division in Washington, described a new method for quantifying increases in carbon dioxide in the hard-to-measure portion of the upper atmosphere known as the thermosphere, which can't be reached by balloons and aircraft.

In that region, more than 50 miles above Earth's surface, carbon emissions cause cooling rather than warming because carbon dioxide molecules collide with oxygen atoms and release heat into space. Because such cooling makes the planet's atmosphere contract, it can reduce drag on satellites and debris that orbit the earth, possibly having "adverse consequences for the orbital debris environment that is already unstable," the researchers wrote.