LSAT 148 | Section 4 | Logical Reasoning: Q15

LR Question 15 Explanation

QUESTION TEXT: Global warming has contributed to a rise in global sea…

QUESTION TYPE: Most Strongly Supported

FACTS:

1. Global warming has contributed to sea level rise in multiple ways. One is that ice melts. Another is that warmer water expands and has a larger volume.
2. But, this expansion is lowered because people have built many artificial reservoirs that prevent water from reaching the sea.

ANALYSIS: There’s not much you can say about these two statements. Basically, warming has caused melting of ice and the expansion of water: both of these raise sea levels. But, sea level has risen less than it otherwise would have due to reservoirs.

Suppose sea level started at 100 units, and now it has risen to 103 units. What can you tell from this information? Not much. Two factors raise it: melting ice, and expanding water. We don’t know from sea level rise alone how much each factor accounts for the rise. Further, since reservoirs have acted against sea level rise, they also throw off any purely numbers based analysis. Maybe the actual rise was 5 units, but reservoirs held back two units for a net rise of 3.

___________

1. What dispute? The stimulus didn’t mention any conflicting stories.
2. This is entirely unsupported. The passage offered two explanations: melting ice, and also an expansion of warming water.
3. Rubbish! The author explained that we know two ways warming has contributed to sea level rise: melting ice, and thermal expansion of water.
4. The stimulus didn’t say this. This answer just mixes together two terms that appeared in the stimulus. It’s the equivalent of someone talking about law school admissions saying “Your GPA is equal to your test date”. The words are all real, but it makes no sense.
5. CORRECT. If melting ice explained all of the change in sea level rise, then we would know that the volume of increased seawater was equal to the amount of melting ice. But, the question gives two other explanations for sea level change: heated water increases sea level rise, and land reservoirs decrease it. So, to gauge ice melt, we would need to look at all three factors.

Recap: The question begins with “Global warming has contributed to a rise”. It is a Most Strongly Supported question. To practice more Most Strongly Supported questions, have a look at the LSAT Questions by Type page.