How does a greenhouse work, and why is the analogy of the earth's atmosphere to a greenhouse imperfect?

Question

What will be an ideal response?

Answer 1

Answer: Greenhouses are made primarily of glass, which is transparent to incoming shortwave radiation but opaque to outgoing longwave radiation. The glass therefore allows in more radiation than is allowed to escape, causing the temperature inside the structure to be warmer than outside. In that regard, a greenhouse is similar to the atmosphere, which also transmits most of the incoming solar energy but absorbs the vast majority of longwave radiation emitted upward by the surface. The analogy breaks down, however, when we incorporate the effect of convection. A greenhouse not only reduces the loss of energy by longwave radiation but also prevents the loss of sensible and latent heat by convection. In contrast, the greenhouse gases (those that absorb longwave radiation) of the atmosphere do not impede the transfer of latent and sensible heat. Thus, it would be more accurate if the term "greenhouse effect" were replaced by "atmospheric effect."