"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.
Which one of the following, if true, would count as evidence against the scientist’s explanation of Earth’s warming?
(A) 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.
(B) Most of the warming occurred before 1940, while most of the buildup of minor gases in the atmosphere occurred after 1940.
(C) Over the last century, Earth received slightly more solar radiation in certain years than it did in others.
(D) 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.
(E) The accumulation of minor gases in the atmosphere has been greater over the last century than at any other time in Earth’s history." "A. Incorrect. The scientist doesn’t mention pollution, and the origin of the gases isn't part of the reasoning. This option tries to distract by bringing in outside knowledge about pollution and climate change, but the gases could have come from natural sources.
B. Correct. This answer undermines the argument by showing that the supposed cause and effect happened at different times, suggesting the warming may have had a different cause.
C. Incorrect. This misses the point. A 0.5-degree increase is significant, and small variations in solar radiation are unlikely to explain it. Plus, the argument deals with long-term averages—not just fluctuations in specific years. This answer only notes increased radiation in some years, not a consistent trend.
D. Incorrect. The argument focuses on long-term atmospheric changes and rising temperatures. This option talks about volcanic dust and particles but doesn’t indicate whether those levels have changed over the relevant time period.
E. Incorrect. While this could offer some support for the argument—suggesting an increased warming effect from minor gases—it doesn’t weaken it, which is the goal of the question."
A. Incorrect. The scientist doesn’t mention pollution, and the origin of the gases isn't part of the reasoning. This option tries to distract by bringing in outside knowledge about pollution and climate change, but the gases could have come from natural sources.
B. Correct. This answer undermines the argument by showing that the supposed cause and effect happened at different times, suggesting the warming may have had a different cause.
C. Incorrect. This misses the point. A 0.5-degree increase is significant, and small variations in solar radiation are unlikely to explain it. Plus, the argument deals with long-term averages—not just fluctuations in specific years. This answer only notes increased radiation in some years, not a consistent trend.
D. Incorrect. The argument focuses on long-term atmospheric changes and rising temperatures. This option talks about volcanic dust and particles but doesn’t indicate whether those levels have changed over the relevant time period.
E. Incorrect. While this could offer some support for the argument—suggesting an increased warming effect from minor gases—it doesn’t weaken it, which is the goal of the question.
