LSAT 143 | Section 1 | Logical Reasoning: Q5

LR Question 5 Explanation

QUESTION TEXT: Environment minister: Because of our concern about…

QUESTION TYPE: Weaken

CONCLUSION: Planting trees will help us meet our commitment to reducing carbon dioxide (CO2) emissions.

REASONING: Trees absorb carbon dioxide (CO2).

ANALYSIS: This seems like a good argument. But it’s a weaken question, so there must be something wrong with it.

I couldn’t prephrase anything here. I just went into the answers knowing I was looking for something that explained why trees wouldn’t reduce CO2 emissions even though they absorb CO2.

Note the difference between emissions and absorption. The right answer shows tree planting causes more emissions. That’s not contradicting the idea that trees also absorb CO2.

___________

1. This describes a difficulty in planting trees. But the environment minister wasn’t arguing that it would be easy to plant trees.
   Instead, they’re talking about what would happen if we plant a large number of trees.
2. Who the hell cares whether the proportion of deforested land has increased faster or slower than CO2 emissions?
   This is an irrelevant comparison. There are very few cases where an answer like this is right. They’re mostly nonsense.
3. CORRECT. This shows that, in the short term, planting trees releases more CO2 than it absorbs.
4. It might be nice to reduce emissions faster, but that’s irrelevant to the conclusion. The environment minister is making a factual argument: what will happen if we plant trees?
5. The minister wasn’t talking about other gases. They didn’t claim that trees planting is a complete solution to global warming. They only made the very limited claim that planting trees will reduce CO2 emissions.