Primary Source of Greenhouse Gases

Steps:

• Recall that global warming results from increased greenhouse gases like CO2 trapping heat in the atmosphere.
• Evaluate each option's link to greenhouse gas emissions.
• Compare contributions: fossil fuel burning releases the most CO2 annually.
• Select the option with the largest impact based on scientific consensus.

Why C is correct:

• Burning fossil fuels releases vast amounts of CO2, the primary greenhouse gas, directly increasing atmospheric concentrations per the greenhouse effect.

Why the others are wrong:

• A: Acidic gases like SO2 cause acid rain, not significant heat-trapping.
• B: Deforestation reduces CO2 absorption but accounts for less emissions than fossil fuels.
• D: Sewage pollution harms aquatic ecosystems without adding greenhouse gases.

Final answer: C