Does recycling actually save energy? The short answer is yes, although the amount varies by material. For some materials, it saves a lot of energy, and for other materials not as much. Extracting and processing raw natural resources (such as mineral ores or oil) is very energy intensive, and recycling uses less energy because it does not require extraction and often requires less processing of materials.
Aluminum is one material that uses much less energy to recycle than to produce new- about 95% less. Processing aluminum ore (bauxite) into metal requires a very large amount of heat and electricity. Aluminum that is recycled only has to be cleaned and re-melted, which makes it almost 95% more energy efficient than newly produced aluminum. Another huge benefit of recycling aluminum is that it can be recycled indefinitely and its quality is never degraded.
Recycling glass is not quite as energy efficient: It saves 15-30% of the energy used to produce it new from sand and other minerals. The main energy used in the glass making process is the heat used to melt the mineral mixture, and because recycling glass also requires melting and then re-forming, it still uses a fair amount of energy. However, glass can be recycled indefinitely, and recycling glass prevents it from going to landfills and reduces the pollution associated with extraction, so it does make environmental sense to recycle it.
The energy savings for recycling iron and steel are also high, at about 75%, and also for recycling plastic bottles, at 65-75%. Paper recycling saves about 45% of the energy of producing paper from virgin pulp, although most recycled paper products also contain some virgin material.
In terms of quality degradation, iron and steel can be recycled indefinitely with no loss of quality, whereas plastic can only be recycled once or twice before being manufactured into an item that can’t be recycled (such as fleece or carpeting), and paper can only be recycled 5-7 times before it loses too much quality and can no longer be recycled.
So, yes, recycling does save energy, which means it also reduces emissions of greenhouse gases. Not buying items in the first place saves the most energy, but if you do have papers and containers to get rid of, make sure to recycle!