Greenhouse gas emissions are known to be directly related to the perceived heightened warming of the earth's oceans and near-surface air. But how does recycling help in cutting back on greenhouse gas emissions?

Recycling is used to refer to the reprocessing of previously manufactured products (such as plastic bottles) so that their core elements (in this case, the plastic substances that make up plastic bottles) can be used to make new products later on. It should be clarified that recycling is different from re-use, because the latter simply means that the previously manufactured product (such as a plastic bottle) will be used for other purposes aside from its original use (such as when a plastic bottle is cut in half and then converted into a plant container.)

When previously manufactured products are recycled, this helps in reducing the amount of energy used to produce new products (compared to "virgin production" where products that are manufactured from substances that were taken purely from the earth's environment  also known as raw materials.) One substance that has been quite damaging to the environment is plastic, because it does not degrade and become re-absorbed into the environment. There is also less waste that goes into disposal systems such as landfills when recycling is put into play.

When products are recycled, there is less need to look for raw materials from virgin sources. For example, aluminum is one substance which can be recycled over and over again without a decline in the quality of the substance. When plastic is recycled, up to 70% of energy is saved. If paper is the substance being recycled, up to 40% of energy is saved. When less energy is used to produce a product, that means less greenhouse gases are emitted into the atmosphere, which helps reduce the impact on the environment through the greenhouse effect.

Energy is also saved because there is less of the virgin or raw materials that has to be sought after, there is less energy needed to transport these virgin materials from their original sources, and there is less energy to be expended trying to clean up the environment when pollutants like non-biodegradable aluminum and plastic containers are dumped into landfills.

Some criticize recycling since there is still a level of energy required to transport recyclables to recycling centers and recycling plants, and in the recycling process itself. However, the energy savings derived from recycling are considerable, and much less energy will be used to make new products from recyclables compared to the use of virgin materials for manufacturing new products. Another criticism is that recycling can become impractical because the cumulative costs for recycling a certain product may outweigh the environmental benefits derived from recycling.

Despite such criticisms, it is generally accepted nowadays that recycling does help the environment by significantly reducing demands on energy supplies, so that less greenhouse gases are emitted, and can be a cost-effective solution in certain cases.