Question

1. how can a renewable resource become unusable for human purposes?

Explanation:

A renewable resource can become unusable when it is overexploited faster than it can replenish, or when it is contaminated by pollution to a degree that makes it unsafe or unfit for its intended human use. For example, freshwater (a renewable resource) can become unusable if it is polluted with industrial waste or agricultural runoff, or if groundwater is pumped out faster than aquifers can recharge.

Answer:

A renewable resource can become unusable for human purposes in two primary ways:

1. Overexploitation: When the resource is consumed or harvested at a rate far faster than its natural replenishment cycle. For example, overlogging forests faster than trees can regrow eliminates usable timber and destroys the ecosystem supporting the resource.
2. Pollution/Contamination: When the resource is tainted with harmful substances that make it unsafe or unfit for use. For example, freshwater (renewable via the water cycle) can become unusable for drinking or irrigation if contaminated with industrial chemicals, sewage, or agricultural runoff.