Q21 - A study of 30 years of weather pattern records

[ohthatpatrick]

Question Type:
Necessary Assumption

Stimulus Breakdown:
Conclusion: It's undeniable that human activity has significant, large-scale effects on weather.

Evidence: A study looked at 30 yrs of weather patterns in a few urban areas and found that weekends were cloudier than weekdays . No naturally occurring seven day cycle is significant enough to be causing that.

Answer Anticipation:
Like almost all Causal arguments, the author sees a CURIOUS FACT (why do weekend days tend to be cloudier than weekday days?) and comes overconfidently to ONE POSSIBLE EXPLANATION (it must be human activity).

Our #1 thought is, "How ELSE could we explain this curious fact?",
and our #2 thought is, "How plausible is the author's explanation?"

#1. The author ruled out the possibility that there is some natural 7-day cycle causing this. If we can't say natural, and we're trying to avoid agreeing with the author by saying it's related to humans, what options are we left with? I guess we could say there's some naturally occurring cycle that isn't 7 days long but still ends up resulting in a tendency towards cloudier weekend days. Maybe there is a 14 day cycle that occurs naturally in which cloud-promoting things occur on days 1 and 2 and on days 7 and 8.

#2. The author is assuming that it's plausible that human activities could be of enough significance to cause measurable weather patterns, and that humans potentially have a 7-day cycle that could explain cloudier weekends.

Correct Answer:
E

Answer Choice Analysis:
(A) This appeals to our common sense, but the author never spelled out this connection. Since we know he's thinking that cloudier weekends result from human activity, we might assume it's connected to the work week in some way, but who knows if it's related to industrial activity. Maybe it's related to when we drink the most alcohol / when we do the most driving (hopefully not at the same time). The author hasn't committed herself to any specific way in which human activity causes this pattern.

(B) That's too strong. The author could happily allow that some 7 day cycles exist in the these three urban areas. No matter what, he's already said that there aren't any 7 day cycles in nature that are powerful enough to produce weather patterns.

(C) Conditional answers should be analyzed by comparing them to the argument core: DID the author make a move from "we know that living organisms have an appreciable large-scale effect on weather" to "thus, it must be in part from humans"?

No. The author made a move from "We know that there is a weather pattern and that no natural 7-day cycle could explain it" to "thus, it must be in part explainable via human activity".

(C) is appealing because its language is mostly germane to the argument. But take a step back and think about how strong an idea it is: "In every single case in which living organisms have had an appreciable large-scale effect on weather patterns, it's been partly because of humans?" This means the author denies that prior to humans existing on Earth (and after humans are gone), living organisms never have an appreciable large-scale effect on weather patterns (I think algal growth was a huge factor in a couple of Earth's previous cycles of climate change / mass extinction).

(D) This answer starts with "IF conclusion", which is always wrong. The author DOES assume that if we're seeing a cyclical pattern, then there should be something that's appreciably affecting large-scale weather. He assumes that cycles don't just spontaneously come from nothing. But that would be (D) in reverse.

(E) YES, the author seems to think that if we were to explain this cloudy weekend pattern with some natural cause, then we would have to look at 7 day cycles. All the author looks at is 7 day cycles (implying that other types of natural cycles couldn't explain this cloudy weekend cycle). By ruling out 7-day cycles in nature, the author rules out (in her mind) ALL possible natural causes for this cycle, and that's how she arrives at her conclusion that this must be caused by humans.

If we negated this, it would be saying, "At least some 7-day weather patterns that have a natural cause are NOT caused by 7 day cycles". That weakens the argument because it makes it possible that there IS still some natural cause for the cloudy weekend cycle, and that it's NOT undeniable that it's caused by humans.

Takeaway/Pattern: Tough one, I'd say. It still fits into the LSAC catalogue of Causality. In reaching her overconfident causal conclusion, the author fails to consider other possible causes for the cloudy weekend cycle. She rules out the possibility of 7-day natural cycles being the cause, but she doesn't rule out the possibility of other natural cycles being the cause. Hence, she assumes that 7-day natural cycles are the only possible natural causes to consider for this cloudy weekend weather pattern.

#officialexplanation

[vonv28]

Thank you for the detailed response. I think I understand (on a high-level) why E is right versus all the other answer choices. However, I'm still tripped up by the language in that answer choice -- particularly the use of the word "cause". What does "then that cause" specifically refer to in the context of the stimulus?

[BasselA46]

Thank you for the detailed response. I think I understand (on a high-level) why E is right versus all the other answer choices. However, I'm still tripped up by the language in that answer choice -- particularly the use of the word "cause". What does "then that cause" specifically refer to in the context of the stimulus?

Hey vonv28, I also struggled with the wording of the last choice. I chose it during my practice run despite not at all understanding what it meant. I just had to make do with eliminating the others.

After reading the explanation above, I went back and re-read the answer choice and it still seemed worded awkwardly. I reworded it like this and it really helped:

Original: If a weather pattern with a natural cause has a seven-day cycle, then that cause has a seven-day cycle.

Rewording: If a weather pattern with a seven-day cycle has a natural cause, then that cause has a seven-day cycle.

In other words, if a weather pattern that recurs every seven days is caused naturally, then the underlying natural cause must also follow a seven-day cycle.

Hope this helps.

[StratosM31]

I'm still struggling with completely eliminating (C). Can somebody verify whether my explanation is correct?

P1: weekend days tend to be couldier than weekdays.
P2: there cannot be a seven-day cyclical natural cause of large-scale, measurable effects on weather.
C: human activity has at least one appreciable, large scale effect on weather (based on my understanding, it's the effect in premise P1).

(C) is not necessary to be assumed. Living organisms could also have large-scale, appreciable effects on other weather patterns without the effects of human activity involved, but not that particular one discussed in the argument or even a weather pattern appearing in a 7-day-cycle.

It could be the case, for instance, that certain bacteria (through a non-7-day-cyclical mechanism) cause winters to be heavier during leap years than regular years (a 4-year-cyclical weather pattern, not a 7-day-cyclical one)... However, the answer choice is talking about all weather patterns, which is too big of a stretch and therefore not a necessary assumption.

If (C) said "... on seven-day-cyclical weather patterns...", for instance, it would be correct in my opinion.

(E)'s scope, as opposed to (C)'s, is narrow enough to work in this case. We do have a seven-day cyclical weather pattern and if for a natural cause it was not necessary to be seven-day cyclical as well, it would wreck the argument, as it would leave open the possibility of non-seven-day-cyclical natural causes.

A more ideal answer choice would be (E) talking about the particular phenomenon in P1 instead of seven-day cyclical weather patterns...

Can somebody please correct me if I'm wrong of give a more satisfactory explanation? I'm really not sure whether my explanation is okay...

[SweetD152]

Thank you very much for solving this task, otherwise I got very stuck on it. I was always bad with my studies, but I was lucky that at least I found your website and https://writix.co.uk/research-proposal-writing-service which has been helping me a lot lately, otherwise the tasks are getting harder and harder. The Custom research proposal writing service is the best I've come across and can free up much more time than I could have imagined thanks to them.