Joel Penner/CC BY-NC 2.0

Dear Pablo: I have a tough one for you: shall we recycle our paper? There are both the CO 2 and the chemical aspects to consider, and there's arguments against recycling paper in each case. Getting rid of the ink used on paper implies bleaching, and the chemical used goes on to pollute rivers. As for the CO 2 , growing a tree is a carbon sink but, in most cases, the trees are not replaced and the industry just clear-cuts the forest. Considering this, is it really a good thing to recycle paper?

For those of us that grew up with the book 50 Simple Things You Can Do to Save the Earth, recycling is second nature. We never questioned recycling and were shocked when the Financial Times declared that recycling is utter rubbish and when Michael Moore proclaimed that he stopped recycling in Stupid White Men. But maybe they were right.

Recyclables often do not get recycled due to food contamination (pizza boxes and paper plates), low commodity values (glass), and lack of the required infrastructure (TetraPaks). Perhaps the act of recycling just lulls us into a false sense of virtuousness that enables us to consume more materials goods without the guilt, forgetting that Reduce and Reuse come before Recycle. So, is paper really worth recycling?

© Pablo Päster

How is Paper Made?

Paper production begins with the harvesting of trees, which are delimbed and debarked before being chipped into a steaming chemical bath to be turned into pulp. The chemical pulping process removes lignin, the "glue" that holds the cellulose together, leaving long cellulose fibers to be pressed into thin sheets. These sheets pass through large rollers that not only flatten the paper but interlock the cellulose and remove water. Finally, the sheets are spooled onto large rolls to be sent to a printing company or to be cut down to size as office paper.

To produce the bright white paper that companies have come to expect for their printers and copiers, the pulp is also "bleached," a process which removes the remaining lignin. This "delignification" process was once done with sodium hypochlorite (household bleach) but was replaced by chlorine, which was often dumped into waterways.

Now the processes are performed with a combination of various chemicals such as chlorine dioxide, lye, oxygen, ozone, hydrogen peroxide, and enzymes.

Richard Wheeler/CC BY-SA 3.0

How is Paper Recycled?

The paper recycling process begins with your recycle bin; from there it is transported to a sorting facility, and then to a paper mill. Paper is sorted into various categories including office paper, magazines, newsprint, paperboard and cardboard.

Because each successive pass through the recycling system shortens the fibers, cellulose can only be recycled four to six times before it begins to degrade paper quality. Therefore paper from each category can only be recycled into products of the same, or lesser quality. For example, office paper gets turned into office paper or magazines, magazines get turned into magazines or newsprint, etc.

At the paper mill, the paper goes through cleaning and screening, ink removal, which involves mechanical agitation in a water bath and a froth flotation deinking process, and bleaching with peroxides or hydrosulfites to enhance brightness. After that, the renewed pulp is turned into paper.

CC BY-NC 3.0. H005

H005/CC BY-NC 3.0

Since the early 1990s, great strides have been made in paper processing and global use of chlorine has dropped off significantly in favor of Elementary Chlorine Free (ECF) and Total Chlorine Free (TCF) processes. The practice of dumping untreated effluent into rivers has also been replaced with environmental best practices in most developed nations and some developing nations but many environmental concerns still exist.

Worldwide, the pulp and paper industry is the fifth largest consumer of energy, accounting for 4 percent of all the world's energy use. The pulp and paper industry uses more water to produce a ton of product than any other industry. -Earth Greetings



Global paper demand for paper and paperboard is expected to reach 490 million tons by 2020

What is the Greenhouse Gas Impact of Recycling Paper?

Thirty-five percent of municipal solid waste consists of paper products and paper recycling rates reached 63.4% in 2009, so 12.8% of new landfill waste consists of paper.

In the anaerobic (without oxygen) environment of a landfill, paper will eventually be decomposed into methane by microbes. Since methane is a potent greenhouse gas, the impacts are much greater than the equivalent amount of paper being turned into CO 2 by microbes in the aerobic (with oxygen) environment, such as a compost bin. In fact, 1 ton of paper in a landfill will turn into 1.38 tons of CO 2 -equivalents.

Recycling, on the other hand, avoids these emissions, as well as the emissions from logging, raw material transportation and processing, and pulping. Recycling one ton of office paper reduces these emissions by a further 2.85 tons, for a total reduction of 4.23 tons of CO 2 . To put this into context, the average US passenger car emits 5.2 tons of CO 2 per year.

While composting your paper is possible, this only cuts down on the landfill emissions but doesn't offset the production of virgin paper. If you do compost, use paper and other 'brown' material like leaves in a 50:50 ratio with 'green' materials such as kitchen scraps and lawn clippings to maximize your compost's performance. Of course, be aware of adding paper that possible contains chemicals from processing or printing, avoid glossy papers, receipts (which can contain BPA), and colored ink.

So, Should I Recycle Paper?

From a greenhouse gas perspective it is clear that recycling paper is the better choice.

From a chemical pollution perspective it is also evident that the process of deinking and peroxide bleaching has a lower impact than virgin pulp production with its mechanical processing, steam, delignification, and bleaching.

Unfortunately both virgin and recycled paper production require a lot of water (virgin paper requires 24,000 gallons per ton and recycled paper requires 12,000 gallons per ton), emphasizing the importance of Reduce and Reuse before Recycle.

© Pablo Päster

Deforestation is certainly another reason to recycle your paper. While it is true that most developed nations require replanting of cut trees, even where clear-cutting is practiced, there are many more impacts than simply the loss of trees. These include habitat loss, erosion, river and stream siltation, and impacts on local tourism. While replanted trees sequester more CO 2 during their first years of rapid growth than old stands do, the replanting often favors a monoculture of species desirable for future harvest, rather than a more natural diversity of tree species.

So keep in mind: Reduce the amount of paper and other resources that you consume, Reuse them whenever possible (paper has two sides!), and always Recycle! Finally, when you must buy paper look for 100% post-consumer recycled paper to support the value of recycled commodities.