Landfills naturally release methane gas as the waste stored in them decays. Such decay is greatly accelerated by contact with...
GMAT Critical Reasoning : (CR) Questions
Landfills naturally release methane gas as the waste stored in them decays. Such decay is greatly accelerated by contact with rainwater. Some landfill operators use technology to extract methane before it escapes into the atmosphere, but this is an expensive process. A less expensive process, phytocapping, involves placing a layer of soil and dense vegetation on top of a landfill. This prevents most water from reaching the waste and could prevent the production and release of methane. Therefore, in order to reduce methane emissions in the most financially sound manner, landfill operators should adopt this alternative.
Which of the following would it be most useful to determine in order to evaluate the reasoning above?
Passage Analysis:
| Text from Passage | Analysis |
| Landfills naturally release methane gas as the waste stored in them decays. |
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| Such decay is greatly accelerated by contact with rainwater. |
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| Some landfill operators use technology to extract methane before it escapes into the atmosphere, but this is an expensive process. |
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| A less expensive process, phytocapping, involves placing a layer of soil and dense vegetation on top of a landfill. |
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| This prevents most water from reaching the waste and could prevent the production and release of methane. |
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| Therefore, in order to reduce methane emissions in the most financially sound manner, landfill operators should adopt this alternative. |
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Argument Flow:
"The argument starts by explaining the methane problem at landfills, then presents the current expensive solution, introduces a cheaper alternative (phytocapping), explains how this alternative works, and concludes that operators should switch to this more cost-effective method."
Main Conclusion:
"Landfill operators should adopt phytocapping because it's the most financially sound way to reduce methane emissions."
Logical Structure:
"The argument uses a comparison structure: Current solution (expensive but works) vs. Alternative solution (cheaper and potentially more effective) → Therefore choose the alternative. The logic depends on phytocapping being both cheaper and effective at reducing methane."
Prethinking:
Question type:
Evaluate - We need to find what information would be most useful to determine whether the conclusion is sound. This means identifying key assumptions that, when tested, would either strengthen or weaken the argument.
Precision of Claims
The argument makes specific claims about cost-effectiveness (phytocapping is 'less expensive'), effectiveness (phytocapping 'could prevent' methane production), and comparative advantage (it's the 'most financially sound manner'). These claims involve both quantitative comparisons and uncertain outcomes.
Strategy
For evaluate questions, we need to think about what assumptions the argument relies on that we could test. We should look for scenarios that, when taken to extremes, would either make the conclusion much stronger or much weaker. The key is finding information that directly impacts whether phytocapping is truly the most financially sound option.
Whether methane gas is produced by other human-influenced sources. This information doesn't help us evaluate whether phytocapping is the most financially sound option for landfill operators. The argument is specifically about choosing between two methods for landfill methane management, and knowing about other methane sources (like agriculture or manufacturing) doesn't affect the cost-benefit analysis between extraction technology and phytocapping for landfills.
Whether a combination of the methods would eliminate methane emissions. While this might be environmentally interesting, it doesn't help evaluate the argument's conclusion about the "most financially sound manner." The argument is comparing two alternatives, not suggesting they be combined. Plus, combining methods would likely be more expensive than either method alone, which contradicts the focus on financial soundness.
Whether other gases are released into the atmosphere as landfill waste decays. This is irrelevant to evaluating the financial comparison between methane extraction technology and phytocapping. The argument specifically focuses on methane emissions and their associated costs, so information about other gases doesn't impact whether phytocapping is the most financially sound methane reduction method.
Whether people consider current levels of landfill methane emissions to be harmful. Public perception doesn't directly affect the financial analysis that forms the core of this argument. The argument assumes methane reduction is desirable and focuses on the most cost-effective method to achieve it. Whether people are concerned about current levels doesn't change the relative costs and benefits of the two approaches.
Whether methane gas captured from landfills can be sold profitably as a fuel source. This is crucial information for evaluating the argument. The argument assumes extraction technology is simply an expensive cost, but if captured methane can be sold as fuel, this could generate revenue that offsets the higher extraction costs. This could potentially make extraction technology more financially sound than phytocapping (which prevents methane production entirely, eliminating any potential revenue). This information directly impacts whether phytocapping is truly the "most financially sound" option.