The more sunlight our planet reflects back into space, the cooler the global atmosphere tends to become. Snow and ice...

shunhe on December 22, 2019

Hi @Shiyi-Zhang,

(D) is incorrect because the conclusion in the question talks about cooling the atmosphere, whereas (D) talks about how the atmosphere is warmed. It also doesn't talk about reflection of what. Hope this helps.

meganw on May 4, 2020

I don't understand this explanation? The correct answer (c) also talks about warming?

Nicholas-Groblewski on June 12, 2020

Could we please get a better explanation as to why D is incorrect?

Nicholas-Groblewski on June 12, 2020

Nevermind!

guibrasil1993@gmail.com on May 21, 2021

Very Hard strenghten. I was stuck between "C" and "D." Even "E" came up as a potential answer. I think I still have a great difficulty in understanding causal reasoning. I know about the ways of strenghtening a causal argument but identifying the causal assumption and understanding especially the answer choices seems particularly difficulty still. I chose D because it looked like it was eliminating a potential alternate cause to the argument. If the atmosphere derives most of its heat from the passage of light through than there is not something else in snow or ice that could potentially offset their cooling effect on the atmosphere. Please help me out with the question. Really hard and I need a step by step breakdown of it.

SawyerJeppson on August 20, 2021

Hi, I also dont understand how C can be right if D is wrong because it mentions warming?

Ravi on February 7, 2022

@SawyerJeppson, D would likely weaken the argument because we know that snow and ice reflect more sunlight back into the atmosphere, so an Earth covered by snow and ice would be an Earth in which sunlight passed through the atmosphere twice (from the sun to the Earth and then again upon being reflected from the Earth). However, a version of the Earth that's covered by ocean water and land would be more likely to be one in which sunlight only passed through the atmosphere once, directly form the sun. And, if the atmosphere gets most of its heat from sunlight going through it, then it actually appears that snow and ice could actually result in a hotter atmosphere since they encourage sunlight to pass through it twice.

E says that different types of land reflect to differing degrees. The problem is that we don't know exactly which type of soil covers most of the Earth, so this does not provide enough information to strengthen the conclusion.

C looks great because we know that snow and ice make the atmosphere cooler. With C, we also know that ocean water and land make the atmosphere warmer. Thus, if humans covered up more ocean water and land with snow and ice, then it would be more likely to create a cooling effect on the atmosphere.