PT79.S1.Q10 - The more sunlight our planet reflects

Bumblebee

Please offer your help with this question! Apologies for a long post.

We know that snowy land reflects MORE sunlight.
That means snowy land absorbs LESS sunlight. We dont know what effect this ABSORPTION has on earths overall temperature (although I think it is logically implied that absorbing light means absorbing heat so C doesnt add anything new!)

C) explains what the effect of absorbing sunlight has on overall temperature of the earth. Absorbing heat actually warms up the atmosphere.

So when the earth gets more snowy lands+iced ocean surface, which means there will be more sunlight reflected and less sunlight absorbed, the earth temperature will likely decline.

Again, I don't see how C strengthens because I thought more reflection logically implies less absorption. And less absorption means less heat absorbed. So C isnt saying anything new… Of course absorbed heat would warm up the atmosphere?!

Could someone also explain D? It is very tough to eliminate it.

I chose D) because it seemed to work as a defender Strengthener. There may be other factors such as volcanic eruptions that override the temperature change brought by having more snowy surfaces. If that is the case, and the sunlight absorbed plays a minority role in determining the overall temperature of the earth's atmosphere, the conclusion would be weakened. D effectively blocks this possibility by saying that the atmosphere derives most of its heat from sunlight.

Thank you!!

ed.lavado

I believe D helps explain that sunlight heats the earth, but not that reflection cools it. Answer C explains that if there is no reflection, the sun rays will heat up the earth. This strengthens the statement that reflection cools the earth. The point we are trying to strengthen is not what heats the earth, but what cools it down. If that made no sense sorry !

Bumblebee

@ed.lavado

Thank you for your response! I will take another look at the question with your comment in mind!