Nonrenewable energy resources include coal, natural gas, oil, and nuclear energy. Once these resources are used up, they cannot be replaced, which is a major problem for humanity as we are currently dependent on them to supply most of our energy needs.

Although fossil fuels are continually formed by natural processes, they are classified as non-renewable resources because they take millions of years to form and known viable reserves are being depleted much faster than new ones are generated.

A nonrenewable resource is a natural substance that is not replenished with the speed at which it is consumed. It is a finite resource. Fossil fuels such as oil, natural gas, and coal are examples of nonrenewable resources.

Non-renewable energy comes from sources that will run out or will not be replenished for thousands or even millions of years. Most sources of non-renewable energy are fossil fuels. Fossil fuels were created as the remains of marine creatures decayed millions of years ago, under huge amounts of pressure and heat.

Polyester is a synthetic fiber, but its raw materials still come from nature. Most polyester is made out of petroleum, a natural non-renewable resource.

Is wool renewable? Yes, it is one of the only natural fibers that is renewable. Every year, sheep are sheared during the warmer months to give us wool for use as textiles, producing items like clothing and bedding.

The problem is, polyester is not a sustainable textile option, as it is made from polyethylene terephthalate (PET), the most common type of plastic in the world. Recycled polyester, also known as rPET, is obtained by melting down existing plastic and re-spinning it into new polyester fiber.

Like polyester, nylon is made from a non-renewable resource (oil) in an energy-intensive process. It sheds microplastic fibers that end up in waterways and oceans every time it is washed, and because it is not biodegradable, it will end up sitting in a landfill at the end of its product life cycle.