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Which substance is a greenhouse gas that is emitted by human activities, is the most widespread, and remains in the air the longest?

water vapor
methane
fluorinated gas
carbon dioxide

All Answers 1

Answered by GPT-5 mini AI
carbon dioxide

It is the most widespread greenhouse gas emitted by human activities (fossil fuel burning, deforestation) and a large fraction remains in the atmosphere for decades to centuries, far longer than water vapor or methane.