What are the sound reasons (let's put aside the unsound reasons) why increasing recycling is taken to improve sustainability (or equivalently to reduce unsustainability)?
Are there real-world circumstances whereby increasing recycling might worsen sustainability?
The concept of sustainability was originally defined as « meeting the needs of the present generation without compromising the ability of future generations to meet their needs » (United Nations Brundtland Commision, 1987). Following this definition, something is either sustainable or not sustainable; sustainability cannot be “improved” or “worsened” (or it is merely the time before depletion that changes). We are faced to the issue of sustainability because we live in a finite world, with limited amounts of the natural resources we depend upon. When we get rid of rubbish, we often condemn useable material to idleness, which brings us to constantly extract raw material.
Recycling means using raw material that has already been extracted; this reduces the need to extract even more of it to meet consumption wants. Simply enough, to be sustainable or to avoid depletion, the rate of extraction must be brought lower or equal to the natural replenishment rate.
Our use of forests is a good example of unsustainability : world forest cover has been shrinking quickly in the last decade, jeopardizing future generations' ability to enjoy its services (not only generations of humans, but also generations of animal forest dwellers). By recycling forestry products, such as paper and cardboard, we reduce the pressure put on forests and do not impede the latter's ability to replenish. In addition, making paper products form recycled fibers is much less energy demanding.
However, here's the drawback : Products made from recycled materials are often of lesser quality than the object for which the material was previously used. This is called downcycling; the idea that raw material cannot be reused infinitely is intrinsic to it. Also, recycling is an unsustainable activity if it engenders the excessive use of other resources (e.g. Oil for transportation, or energy for transformation). This may occur for certain materials that are shipped overseas to be managed in developing countries at a lower [financial, not environmental] cost.
Still, most of the time, recycling is effective in reducing the demand for raw products and energy. This is especially true when the recycled objects are made from substances that takes very long to regenerate, such as oil (of which all plastics are made).
For recycling to be unquestionably sustainable, it is necessary to review the way the material is transformed and re-processed. And for that reason, reusing before recycling is even better as we aim for sustainability.
For more information :
Recycle Everything: Why We Must – How We Can (Janet Unruh, 2010)
The Story of Stuff (Annie Leonard, 2010)
This answer does a great job of answering how recycling relates to sustainability. So I will focus on where recycling is not sustainable.
For recycling to be sustainable it should not create waste that is more damaging to the environment than discarding the original item would be, and/or less efficient to create the product you end up with at the end of the recycling process, than it would be to extract, and refine from raw materials, or that of a suitable alternative.
Example:
Certain alloys are not easily reforged and the process of forging creates molecular bonds that do not re-purpose well with out breaking those bonds. To break those bonds on many aluminum alloys requires chemicals and often quite a bit of electricity. Most of these chemicals are highly toxic, and create hazardous waste. The effort, waste, and pollution created by recycling these alloys is more damaging to the earth than just discarding the alloy which is chemically stable, and does not create hazardous waste.
I agree with both of the responses above. Primarily the statement from user18: "Still, most of the time, recycling is effective in reducing the demand for raw products and energy. This is especially true when the recycled objects are made from substances that takes very long to regenerate, such as oil (of which all plastics are made)."
And Chad's comment that, "For recycling to be sustainable it should not create waste that is more damaging to the environment than discarding the original item would be, and/or more less efficient to create the product you end up with at the end of the recycling process."
The more we can improve on the effeciency of recycling the more beneficial the process will be to all of us. But consider when we teach the 3Rs, recycling is at the end of that list. It is a misconception that you are being an environmentalist or living sustainably becuase you recycle. Cut back on your consumption FIRST, purchase durable goods, consider recycling the LAST possible option.
From a business/ manufacturing view, should be included in all production whenever possible and always improved on. From the individual/ consumer point of view, it's just one baby step away from the landfill.
