Which of the three major environmental problems is the most challenging because it is irreversible

The correct answer is resource depletion.

Resource depletion refers to the consumption of a resource more briskly than it can be replenished. Natural resources are usually differentiated among the non-renewable and renewable resources.

The most common causes of the depletion of the natural resources are the following:

1. Overpopulation

2. Deforestation and the destruction of Ecosystems resulting in the destruction of the biodiversity.

3. Overconsumption and waste.

4. Pollution and contamination of resources

5. Technological and industrial development.

colors do exist. the color of the sky is actually violet; humans percieve the color of the sky as blue.