Is greenhouse effect beneficial and/or harmful?

Which of the following are TRUE statements relating to the greenhouse effect?

• Which of the following are TRUE statements relating to the greenhouse effect? (There may be multiple correct answers; wrong answers are penalized.) a. The Earth emits infrared radiation (heat). b. The primary attribute of a greenhouse gas is that it absorbs incoming radiation from the Sun (and not radiation from the Earth). c. Mars has a much stronger greenhouse effect than Earth's because its atmosphere is almost entirely CO2. d. Water vapor is a greenhouse gas. e. A planet moves toward stability or balance in terms of heat in from the Sun versus heat radiated from the planet. I know for sure that c. is false and that d. is true. I'm pretty sure that b. is true as well. But I'm slightly unsure when it comes to whether e. and a. are true. Typically this class tends to be very specific with facts and tricks people with the wording of the questions so just be aware of that when trying to answer.

• Answer:

  Sure c is false but so is b. A greenhouse gas traps heat, much if it already accumulated on earth itself, from the sun. So a, d and e.