Increasing levels of carbon dioxide in the atmosphere can lead to a carbon sink on land, where plants absorb more carbon from the air. This process can help slow down climate change. Evidence shows that global photosynthesis has increased significantly due to higher carbon dioxide levels. About half of this increase is likely due to the rising carbon dioxide levels. Data suggests that there has been a historical carbon sink on land, but the exact impact of carbon dioxide on plant and soil carbon is still uncertain. Overall, there is strong evidence supporting the idea that higher carbon dioxide levels are leading to a positive carbon sink on land, although the exact extent and other factors at play are still unclear.