Forests that regrow after fires, logging operations, or other disturbances can sequester huge amounts of carbon dioxide and they play an unexpectedly valuable role in mitigating climate change. This is the conclusion of a study by 60 scientists from across the globe. It is the first time researchers have quantified how much carbon these so-called second-growth forests can sequester — and it turns out it’s huge. The scientists found that over the span of 40 years, Latin American second-growth forests can stash away the equivalent of 21 years’ worth of the region’s human carbon dioxide emissions.