What environmental issue is associated with carbon dioxide (CO₂)?

The association of carbon dioxide (CO₂) with environmental issues primarily stems from its role as a greenhouse gas. Greenhouse gases, including CO₂, are vital in regulating Earth's temperature; they trap heat in the atmosphere, which is necessary for maintaining a climate conducive to life. However, the excessive accumulation of CO₂ due to human activities, such as burning fossil fuels and deforestation, enhances the greenhouse effect, leading to global warming and climate change.

This increased warming affects climate patterns, resulting in numerous environmental impacts, such as more frequent and severe weather events, rising sea levels, and disruptions to ecosystems. Understanding the significance of CO₂ as a greenhouse gas is critical for addressing climate change and implementing policies aimed at reducing carbon emissions and promoting sustainable practices.

The other options relate to different environmental concerns—such as acid rain, ozone depletion, and freshwater resource depletion—however, they do not accurately depict CO₂'s primary environmental role, which is closely linked to its greenhouse gas properties.