The study looked at how much change in plant growth and soil respiration is needed to keep the Earth's carbon balance in check. By combining different ways of studying carbon storage, researchers found that the rate of plant growth is more important than changes in soil respiration for long-term carbon storage. They used a model to show that areas with high plant growth and slow carbon turnover are best at storing carbon. The key to a strong carbon sink is not just how much plants grow, but how fast their growth increases over time.