Scientists have discovered "significant numbers" of bacteria living more than five miles above the Earth's surface that could affect weather patterns worldwide.
"We were sampling really high up in the troposphere and we definitely did not expect to find as many bacteria as we did," says Thanos Nenes, who studies the atmosphere at Georgia Tech University. "Now the basic question we're trying to answer is whether there are enough of them to form ice around them. If they form ice, they could have an important impact on rain, hydrological cycles and climate."
Researchers had discovered bacteria living in the atmosphere before, but Nenes says the bacteria his team discovered live higher than any previously discovered organism. The team found that about 20 percent of all particles they studied were "viable bacteria cells."
"With how dry and cold it is and how much direct sunlight they receive, it's somewhat surprising how much life we found," Nenes says.
With the large number of diverse bacteria discovered, Nenes believes there may be enough organic matter in the troposphere for bacterial communities to grow and thrive in harsh conditions.
"This is just the beginning," Nenes says. "We're trying to see as much as we can about what these bacteria are, how they behave, and whether or not they contribute to the global climate."