Politics-Ethics Question

[Xhad]

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But what is so different between one person burdening society and 500,000? If 500,000 people is where society begins to break down because of the burden then clearly even one person is detrimental to society.

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If a gas is toxic when it comprises 40% of the atmosphere, but harmless in trace amounts, does it follow that we should automatically ban all emissions of that gas?