The amount of fresh water available to meet the needs of Earth's population varies significantly
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.