The earth has a way of changing and adapting to new conditions over millions of years. New species arise, fill ecological niches, and then evolve again when conditions change. There was a time in the earth's ancient past that an adaptation in trees caused pollution in the form of too much lignin. Eventually, a type of microorganism evolved that ate lignin and solved the problem, although it took many millions of years.
Today the pollution is human-driven, and the world has too much plastic. Will something evolve that eats plastic? That's already happened. Scientist discovered a new bacterium they named Ideonella sakaiensis near a plastic recycling facility in Japan. I. sakaiensis manufactures an enzyme that breaks down the plastic called polyethylene terephthalate (PET) into organic molecules it can consume. Other bacteria with such talents have been identified since then.
But we don't have tens of million of years to dispose of plastic. Mother Nature has all the time in the world, but in order to preserve life as we know it, scientists are growing these plastic-eating bacteria and boosting their PETase, which is what the novel enzyme was named. While we still need to reduce our plastic waste, having microbes that decompose it can't hurt. Or can it? When we encourage any species to evolve and thrive, we don't know what the long-term consequences will be. Read more about this research at Real Clear Science.
(Image credit: Dying Regime)