Below is an instruction that describes a task. Write a response that appropriately completes the request.

### Instruction:
Provide an example of a non-renewable source of energy.

### Response:
A non-renewable source of energy is one that is not able to be replenished on a human timescale. Examples of non-renewable sources include fossil fuels such as oil, natural gas, and coal, as well as nuclear energy. These sources of energy are finite and will eventually become depleted over time.