Why are rainforests considered important for stabilizing CO2 levels?

• A. They perform large-scale photosynthesis, which removes CO2 from the air.
• B. They trap CO2 by physical barriers.
• C. They emit methane that offsets CO2 reductions.
• D. They store CO2 without removing it from the air.

Answer: (A)

The main idea is that rainforests help stabilize atmospheric CO2 by removing it from the air through photosynthesis. In these forests, plants are highly productive and shade year-round, so they rapidly take in carbon dioxide and water to build sugars and grow biomass. That carbon becomes stored in the wood, leaves, roots, and eventually in the soil, meaning a large amount of CO2 is pulled out of the atmosphere and kept there for long periods. Because of their vast area and fast growth, rainforests act as major carbon sinks, helping to slow the rise of atmospheric CO2 levels. Disturbances like deforestation or fires can release that stored carbon back, reducing their stabilizing effect. The other statements don’t describe this uptake-and-storage process: physical barriers don’t remove CO2, methane emissions don’t cancel the overall CO2 removal in forests, and storing CO2 is a result of removing it from the air, not something separate from removal.