Why Do Forests Absorb More Carbon Dioxide as They Grow Older?

Forests act like sponges for carbon dioxide. When a forest is young, its trees are small and grow quickly, which means they take in lots of CO₂ from the air. But as the forest gets older, the trees become bigger and more efficient at absorbing CO₂ over time, kind of like how a sponge soaks up more water after it's already wet.