The Earth's microbiome plays a role in keeping the planet balanced for life, writes the University of Arizona's Raina Maier in a guest blog at Scientific American. The air, she notes, is only breathable because microbes began photosynthesizing and releasing oxygen.
But how microbes shaped the Earth was a slow revolution, one that people may quickly undo. Maier writes that it took some 4 billion years for the Earth's microbiome to transform a carbon dioxide-heavy atmosphere into one with only a small percentage of CO2. But, she says, in the last 150 years, people have quickly increased that percentage from 0.03 percent to 0.04 percent. "This change has happened 2,700 times faster than what occurred in the previous 4 billion years," she says.
She adds that how human activities like mining, large-scale agriculture, and burning fossil fuels are affecting microbes is largely unknown, as is how microbes will react to a new climate patterns. "We are just beginning to realize that extensive warming of permafrost soils may release a treasure trove of heretofore frozen food for microbes, increasing carbon dioxide emissions and climate warming to even greater rates than currently exist," Maier says. "Understanding Earth's microbiome is a challenge that rivals going to the moon or developing cures for cancer.