B. 15C instead of 20C
C. 0C instead of -20C
D.15C instead of -20C
Please explain which is the correct answer.
D is the closest choice.
While water vapour is not the 'cause' of the planet being 33C, or 35C in your example, warmer it is the reason. Let me explain. the amount of water vapour is dependent on temperature. As you warm something the capability of that air to hold more water vapour increases. As you cool something the opposite occurs. This is how clouds are formed. therefor, as you warm the planet, the amount of water vapour increases in the atmosphere and the warming due to that additional water vapour is greater than the warming due to that original forcing. If that original forcing was not there there would not be an increase in water vapour.
http://en.wikipedia.org/wiki/Greenhouse_...
D is the closest, although, if there were not also carbon dioxide there would be a lot less water vapor in the atmosphere. and the water vapor which was in the atmosphere would not warm Earth to 15C, but more likely to -15C. Carbon dioxide alone would warm Earth from -20C to -10C. Both are necessary to warm Earth to 15C. Water vapor is the primary reason why our surface temperature is 15C instead of -10C.
D. Jeff M has given you the explanation. Water vapour is the dominant greenhouse gas and responsible for most of the greenhouse effect.
Answer D. Gives the correct temperature range. The Earth is currently (approximately) 15C, without any greenhouse effect it would be (approximately) -20C.
D is the closest, but it is a stupid question it is much more complicated and involved than that,
and choice questions do not reveal whether the answerer has understood the subject.
A. 20C instead of 30C
B. 15C instead of 20C
C. 0C instead of -20C
D.15C instead of -20C
Please explain which is the correct answer.
