Carbon dioxide emissions may be increasing the anxiety over global warming in more ways than one. A new study finds that the greenhouse gas doesn’t just warm our planet’s atmosphere… it hits closer to home by triggering anxiety attacks in panic-prone people.

Carbon dioxide is a normal part of the air we exhale. But when we inhale too much, the gas sets off alarm bells in the brain that warn of impending suffocation and death. It’s enough to make one panic… and it does. Experts have long suspected that the two-and-a-half million Americans who suffer from frequent panic attacks have faulty alarm systems, equipped with sensors that are too easily tripped by low levels of carbon dioxide.

To prove their point, researchers asked sixty-four healthy volunteers to inhale air containing increasing amounts of carbon dioxide. The subjects rated their fear and discomfort after each breath. As expected, the subjects were more likely to report feeling frightened, out of control and out of touch with reality as carbon dioxide levels increased.

The findings could make it easier for scientists to test how well anti-anxiety drugs ease the symptoms of panic attacks, because they can induce feelings of panic in the laboratory setting without exposing subjects to any real danger. The study will also help researchers develop new anti-anxiety treatments for patients with emphysema and asthma. But don’t hold your breath… it could be years before these new drugs hit the market!