The study demonstrates that elevated CO₂ can significantly boost forest productivity, but this benefit is counteracted by the negative effects of ozone pollution. Forests exposed to high ozone levels experienced reduced canopy nitrogen and carbon storage, which could impact their role as carbon sinks. These findings suggest that while rising CO₂ levels may enhance growth, other pollutants like ozone could undermine these gains, posing risks to forest health and their ability to mitigate climate change.