PrepTest 123, Section 2, Question 5

By Brandon Beaver | Published October 29, 2024

Type: Weaken

Difficulty:

Explanations

The simplest weakeners will say, “this has no effect” or “that’s not what has happened.” So, maybe something like, “the outward flow of heat from the planet has always been blocked” or “the outward flow of heat being blocked has no effect.”
A
Nope. Industrial pollution isn’t being accused of anything here.
B
Yup, that would undermine the scientist’s explanation. Why would minor gases be the issue if the bulk of them only started after the bulk of the warming?
C
No. We know the warming is primarily from gas buildup. Don’t go the step too far and assume this nominal amount of radiation in just some years would provide an alternative explanation.
D
No way. Like with C, we’d have to assume that those are the real causes, which we just can’t assume.
E
Nope. This would strengthen the scientist’s explanation.

Passage

Scientist: Earth's average annual temperature has increased by about 0.5 degrees Celsius over the last century. This warming is primarily the result of the buildup of minor gases in the atmosphere, blocking the outward flow of heat from the planet.

Question 5

Which one of the following, if true, would count as evidence against the scientist's explanation of Earth's warming?
Only some of the minor gases whose presence in the atmosphere allegedly resulted in the phenomenon described by the scientist were produced by industrial pollution.
Most of the warming occurred before 1940, while most of the buildup of minor gases in the atmosphere occurred after 1940.
Over the last century, Earth received slightly more solar radiation in certain years than it did in others.
Volcanic dust and other particles in the atmosphere reflect much of the Sun's radiation back into space before it can reach Earth's surface.
The accumulation of minor gases in the atmosphere has been greater over the last century than at any other time in Earth's history.