Where is the highest amount of carbon dioxide found in?

The highest concentrations of carbon dioxide are typically found in the atmosphere, particularly in urban areas and regions with significant industrial activity. However, natural sources such as volcanic eruptions and deep ocean waters can also exhibit elevated CO2 levels. Additionally, during photosynthesis, plants absorb CO2, leading to lower concentrations in densely forested areas compared to more barren regions. Overall, the global average atmospheric CO2 concentration has been steadily rising due to human activities.