Young tropical forests play a crucial role in slowing climate change. …But, according to a new study, CO₂ absorption may be slowed down by the lack of a crucial element that trees need to grow: nitrogen. Published in Nature Communications … the study estimates that if recovering tropical forests had enough nitrogen in their soils, they might absorb up to an additional 820 million metric tons of carbon dioxide each year for a decade. “When we added nitrogen to the soil, forests grew back almost twice as fast in the first 10 years,” said ecologist Sarah Batterman, senior author on the paper. Rather than fertilizing young forests, the scientists recommend planting nitrogen-fixing trees in regenerating forests and, when possible, prioritizing forest restoration on lands that receive nitrogen pollution from farms and factories.