Answer to Question 1
Answer: What makes the greenhouse effect work is the presence of atmosphere. The Moon has no atmosphere, so all incoming solar radiation reaches the surface. When the surface is heated and radiation is re-emitted in longwave form, all longwave radiation returns to space. Earth and Venus, however, both have atmospheres, with Venus' much thicker than Earth's. When longwave radiation is emitted by both planets, the greenhouse gases in the atmosphere absorb some of the radiation, resulting in near-surface heating. This heating will be more significant on Venus because of the abundance of greenhouse gases in the atmosphere.
Answer to Question 2
Answer: Humans living low-lying islands, coastal cities, and wetlands will be threatened by increasing flooding and may be displaced.
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