Final answer:
To reduce atmospheric carbon dioxide, one can contribute to reforestation efforts and avoid deforestation, as trees absorb CO₂ during photosynthesis. Alternative energy sources and reducing certain agricultural practices are also key measures.
Step-by-step explanation:
One way to help reduce the level of carbon dioxide in the atmosphere is through reforestation—planting new trees and avoiding deforestation. Trees and plants absorb carbon dioxide and store it as part of their biomass through a process called photosynthesis. Since carbon dioxide is a major greenhouse gas that contributes to climate change, by increasing the number of trees, we can enhance the natural capacity of the environment to act as a carbon sink, thereby mitigating the effects of excess CO₂ in the atmosphere. Aside from reforestation, other measures include using alternative fuel sources that do not produce carbon dioxide, like solar and wind energy, and reducing activities such as livestock agriculture which contribute significantly to greenhouse gas emissions.