Logical Reasoning

PT140 · S2 · Q12 Though Earth's human population

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Though Earth's human population is increasing, it currently uses only a relatively small fraction of the supply of fresh water.

Conclusion (Thus)

Claims that water shortages will plague humankind in the near future unless population growth trends change are simply mistaken.

rephrase: Even if population growth trends continue, water shortages aren't necessarily going to plague humankind.

Evidence

Even though human population is increasing, it currently uses only a relatively small fraction of Earth's supply of fresh water.

Evaluate

Given that ... we only currently use a small fraction of Earth's supply of fresh water How can we say that ... as population continues to increase, water shortages will plague humankind?

When we're dealing with Predictions, we usually want to consider what other sort of stuff could change in the future.

Maybe currently we're only using a small fraction of Earth's fresh water supply, but we haven't yet faced the ravages of climate change. Perhaps we will soon face climatic feedback loops from climate change that will evaporate tons of our water or taint our water or make a lot of it inaccessible.

Maybe the (natural or man-made) distribution networks that move water from one place to another will get impaired.

Goal

It's hard to know what the correct answer will be addressing, but it will probably deal with something other than Earth's water supply, as a potential factor in how water shortages will soon plague us.

Let's just keep the Anti-Conclusion in mind,

12.

Which one of the following, if true, most seriously weakens the argument above?

  1. Population growth trends are notoriously

    No Impact

    Whether trends are hard or easy to predict doesn't matter. It doesn't actually strengthen or weaken this argument to talk about population growth trends, unless we're saying, "As population growth trends continue, something else will happen." The people the author is disagreeing with have made a conditional claim: If population growth trends continue, then water shortages will plague humankind. We can never strengthen or weaken a conditional claim by talking about whether it's trigger will or won't come true. Suppose I said, "If humankind ends up settling Mars, there will still be racism on Mars." You can't argue with me on that statement by saying, "Humans are never gonna settle Mars." This author hasn't committed to any guess regarding whether population growth trends will or won't continue, and she isn't relying on anyone's prediction of whether they will.

    7% picked this

  2. Correct

    The amount of fresh water

    Why this is right

    This definitely isn't attractive to most of us on a first pass, but it ends up being the best option we get for arguing our Anti-Conclusion that "even though we only use a small fraction of the fresh water supply, it still might be the case that water shortages will plague humankind in the near future". What this answer is suggesting is that the allocation of Earth's water supply from region to region is very lumpy. Norway might have a ton more than they need. Mozambique might have a ton less than they need. (We can think of this the way we think about fossil fuels -- certain areas of the world, like the Persian Gulf, have way more of Earth's total supply of oil than other regions do. And their control of such a precious resource has led to much violence already; imagine how bad it could get if there were a genuine global shortage of oil!) That's what this answer is going for --- even though the global supply of fresh water might be more than ample, if 60% of it is hidden in snowpack in the Himalayas, that doesn't do anything for all the drought-struck countries throughout the world. In a sense this is a Part vs. Whole flaw. Just because the Whole planet has an ample fresh water supply doesn't mean each Part (each country / each region) of the planet has an ample fresh water supply. Some of us may think, "This answer still just sounds like water shortages will plagues some regions / some countries. How is that plaguing all of humankind?" 1) answers don't have to be perfect to be the best available 2) even when tragic things aren't happening to your country, they're happening elsewhere, that can "plague humankind", in the sense that the rest of us feel terrible about what's going on, in the sense that wars can break out over scarce resources, or in the sense that if something afflicts most humans, it's still fair to say it afflicts "humankind".

    Skill tested: Weaken · how this choice captures the argument's function is the move to repeat next time.

    56% picked this

  3. Not all of Earth's population

    Too Weak

    The correct answer to Strengthen, Weaken, and Paradox is almost never as weak as "one data point" (i.e. language like some, sometimes, can, could, may, not all, not necessarily) Since "Not all A's are B" really just means that "Some A's are not-B", this answer is just telling us that, "at least one member of Earth's population will not adopt water conservation methods in the near future". His name is Greg and he sucks. We can't make a strong argument that "water shortages are going to plague humankind" by saying, "Greg, and possibly other people, are not going to adopt water conservation methods".

    5% picked this

  4. If Earth's population continues to

    Too Weak: eventually

    This argument is about whether water shortages will or won't plague humankind in the near future. This answer is about whether Earth's population will eventually (before the end of time) outstrip all available resources.

    27% picked this

  5. The percentage of fresh water

    Irrelevant Distinction

    We don't get any specific value out of learning which categories of water usage are growing at faster rates vs. growing at slower rates. This argument isn't about any one specific category of water usage. All those categories affect supply/demand of fresh water.

    5% picked this

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