Question

which statement explains why many scientists believe that carbon dioxide has likely contributed more to global warming than other greenhouse gases?
carbon dioxide is emitted from fertilizers used in farming.
other greenhouse gases trap more heat than carbon dioxide.
carbon dioxide has increased as a result of increased human activities.
carbon dioxide is emitted from commercial refrigeration.

Explanation:

To determine why carbon dioxide is believed to contribute more to global warming, we analyze each option:

• Option 1: Emission from fertilizers is not a primary reason for CO₂'s major role in warming.
• Option 2: Other greenhouse gases (like methane) can trap more heat per molecule, so this is incorrect.
• Option 3: Human activities (burning fossil fuels, deforestation) have significantly increased CO₂ levels in the atmosphere. Higher concentrations, even if other gases trap more heat per unit, mean CO₂ contributes more overall to warming due to its large volume.
• Option 4: Emission from commercial refrigeration is about other gases (like CFCs) or minor CO₂ sources, not a key reason for CO₂'s major warming role.

Answer:

C. Carbon dioxide has increased as a result of increased human activities