Why do we recycle paper?

Question

Recycling metal and some plastics makes complete sense to me. Why bury something in a landfill that you'll have to find and dig up more of later. What I don't get is why we recycle paper products, especially those created with plant matter.

My understanding is that the fossil fuels we use for energy were generated during the Carboniferous period by burying carbon rich plant matter in anoxic swamps. If we are causing climate change by reversing this effect, dumping tons of carbon back into the carbon cycle... why recycle paper, or other products created, necessarily, by pulling carbon from the atmosphere?

Wouldn't a more beneficial method of disposing of such waste be to find a method of isolating them from the effects of weathering and keeping the carbon they contain locked up as long as possible?

The second and third paragraphs do not follow logically. It's almost as if you are thinking that by recycling paper we are putting carbon back in the atmosphere? Paper recycling decreases the amount of trees we have to log to produce paper-consumption demands. Trees lock up carbon and are environmentally beneficial in countless other ways. So, we need to limit the amount of trees we remove. Plus, if you throw paper in a landfill, it decomposes and creates more greenhouse gases. Recycling is about re-use, which saves our natural resources and limits waste/pollution — f.thorpe, Apr 15 '15 at 00:52
@farrenthorpe - You are reading it wrong. He's arguing (perhaps erroneously) that burying paper would form a nice carbon sink. — David Hammen, Apr 15 '15 at 16:30

score 16 · Answer 1 · answered Apr 15 '15 at 17:24

Wouldn't a more beneficial method of disposing of such waste be to find a method of isolating them from the effects of weathering and keeping the carbon they contain locked up as long as possible?

You are ignoring a number of factors here.

A good deal of energy, much of it non-renewable, is needed to turn trees into paper. The trees need to be cut down (requires petroleum), transported to the saw mill (more petroleum), sawed and chipped (requires electricity), transported again (more petroleum). Once it gets to the paper mill, it needs to be pulped (requires petrochemicals, which need to be transported (requires petroleum)). The pulping process also consumes a good deal of electricity, as does the process of turning pulp into paper.

Bottom line: Paper has a positive carbon footprint.

If you send that paper to a landfill after using it, the carbon in that paper will be released to the environment, and in fairly short order. On the other hand, recycling paper bypasses a number of the steps involved in turning trees into paper. Turning paper into pulp is easy. Recycling paper reduces paper's positive carbon footprint by a significant amount.

The question specifically asks about finding a method of isolating wastes from the effects of weathering. That's not easy. Anaerobic bacteria find paper to be quite yummy. A deep ocean trench might work, but it would be better to not make paper in the first place. Growing and harvesting trash trees and then sending them into the deep would be more effective. A number of early geoengineering proposals suggested doing just that. There are big problems here, mostly unintended consequences. Deep sixing trees in deep ocean trenches is no longer viewed as a viable carbon sequestration scheme.

You are correct that it uses energy to turn trees into paper but modern plantation forestry cuts and chips the trees on site. This packs a lot more wood into the transport. The pulp mills are typically close to the wood source whereas with recycling you have trucks collecting a highly distributed paper source and transporting it greater distances. I would like to see the numbers before I get off the fence on this one. — haresfur, Apr 15 '15 at 22:03

score 8 · Accepted Answer · edited Apr 17 '15 at 22:53

My understanding is that the fossil fuels we use for energy were generated during the Carboniferous period by burying carbon rich plant matter in anoxic swamps. If we are causing climate change by reversing this effect, dumping tons of carbon back into the carbon cycle... why recycle paper, or other products created, necessarily, by pulling carbon from the atmosphere?

Wouldn't a more beneficial method of disposing of such waste be to find a method of isolating them from the effects of weathering and keeping the carbon they contain locked up as long as possible?

I think part of your question has gone unanswered, so I'll give it a shot.

I'm not sure there's enough anoxic bodies of water/swamps available for that kind of project, and 2, it's not easy to bury something in a swamp, there would be issues of transportation (many million tons of recycled paper), so it would be fairly work intensive. It's not easy burying millions of tons under a swamp and paper floats - so, there's no guarantee it would be long term anyway.
Let's look at how much paper is used. Roughly 3.3 billion cubic meters of trees are harvested every year, over half of that goes into fuel for cooking and heating. 17% goes into making paper (presumably that would go up if we stop recycling, so lets say 20%-25%. And wood is about 50% carbon (sources all in the link below)

http://www.tappi.org/paperu/all_about_paper/faq.htm

So, theoretical anoxic stored used paper & cardboard.

3.3 billion cubic meters (harvested per year) × 20%-25% (paper/cardboard share) × 50% (carbon content) × let's say density of 900 kg per cubic meter (because the estimate is size not mass). If you returned all the paper and cardboard into anoxic storage, roughly 0.3 - 0.37 billion tons of carbon (not CO₂, just carbon) could be stored per year. Mankind's production, about 8 billion tons of carbon. (I'm calculating carbon not CO₂ which is about 30 billion tons per year).

So, the simple truth of it is that we use a lot more oil than we do paper. Even if every last scrap of used paper and every bit of used cardboard were all anoxicly stored, that would reduce our carbon footprint maybe 3%-4%. If you add to that, every bit of discarded wood - what then? 5%. 6, maybe 7%, and such actions would be both energy intensive and require increased tree cutting mentioned in the other answers, so there would be a fair measure of diminished returns.

A friend, who I used to debate this subject with often, had a similar idea - you want to fight greenhouse gas, he'd say, just build more things out of wood. Wood stores carbon, which it does. He was right, but we can't grow and harvest enough wood to make a real dent in our carbon footprint. Besides, when wood is harvested, and turned into furniture or a house or whatever else, energy goes into that. I'm not sure how much is even saved from the footprint by building more things from wood.

It's a good question but I think, ultimately, not practical.

http://www.paperimpact.org/how-much-wood-is-harvested-each-year-world-wide-and-what-is-it-used-for-1941.html

You wouldn't need to store the paper/wood products in a swamp because landfills go anoxic very quickly. Paper persists for a very long time there. even if you did generate methane that is recoverable and would offset additional fossil fuel use. Not a complete solution but should be considered as part of the mix. — haresfur, Apr 15 '15 at 21:52
Logging for pulp dries out and exposes the forest soils, which then lose carbon, sometimes a great deal of carbon, which would otherwise stay there for tens or even thousands of years. It's reforestation that draws down atmospheric CO2 (the depopulation of the Americas by disease may have led to the cold years in the 16th c. as the NAmerican hardwood forests expanded, for instance). — cphlewis, Apr 15 '15 at 22:04
My answer was roughly thought out, and I appreciate both comments. I'm also a huge fan of reforestation, but I've run the numbers and we don't have enough space to use reforestation as a solution to the 30-33 billion tons of CO2 we put in the atmosphere every year. Reforestation (again - big fan), but it's at best, part of the solution. We'd have to reforest 12-20 Texas sized areas to actually reduce our carbon footprint to friendly levels. Reforesting just 1 Texas sized area would be a tremendous effort. — userLTK, Apr 15 '15 at 23:33
@Haresfur, ultimately, you'd have to run the numbers, which I'm not up for, but, assuming that paper and cardboard in a landfill instead of recycled, and then 5%-10% more trees are harvested every year - I'm not sure there's a net gain in there worth pursuing. Energy goes into making paper. If less energy goes into recycling paper and less trees are cut - the benefit might be small. I'm not opposed to anything that would work, even the counter-intuitive idea of stop recycling paper, but I have a hard time seeing a helpful reduction in carbon footprint by putting paper in landfills. — userLTK, Apr 15 '15 at 23:38
@cphlewis, in this part of the world, logging and deforestation increase soil moisture because ET decreases. And soil carbon seems to recycle faster than that. — haresfur, Apr 17 '15 at 02:13
Does deforestation increase SOM where you are? That's really surprising -- where is it? — cphlewis, Apr 17 '15 at 02:14

score 5 · Answer 3 · answered Apr 15 '15 at 02:28

This question (and my answer) borders on opinion but is a good example of the interface between the science and policy.

Forests and tree plantations are a sink for carbon but that sink is a one-off credit because trees die and decay, cycling the carbon dioxide back into the atmosphere. So growing new trees will tie up additional carbon dioxide from the atmosphere but maintaining existing mature forests will be carbon neutral. Harvesting existing forests without reforestation can increase atmospheric carbon dioxide if the wood is burned or allowed to decay.

If the paper and wood products are sequestered from decay or if the decay is significantly slower than the existing cycle, then atmospheric carbon sequestration will increase if the forest is allowed to regrow and the forest sink is maintained. So the original supposition is basically correct provided it doesn't lead to increased deforestation.

There are some additional considerations that would have to be addressed by a life-cycle analysis of the paper industry. Does it take more fossil fuel to make paper from harvested trees or from collecting, sorting, transporting, and reprocessing paper? That could tip the balance one way or another. In addition, the non-carbon value of the forests should be considered. Will the forestry cause excessive environmental harm through habitat shifts, road building, increased stream sedimentation during harvest, etc?

score 4 · Answer 4 · answered Apr 15 '15 at 00:45

The main source of "fresh" paper is trees. Forests, either natural or plantations, have to be cut down to satisfy our need for paper. It is well established that forests are a major sink for carbon.

The more paper that get recycled the fewer the forests that need to be clear felled for paper production and the less disruption to the Earth's carbon sinks and the so called "lungs of the Earth".

Recycled paper get used in a variety of products, cardboard boxes being one of the main ones, but also toilet paper, tissues, disposable nappies/dipers, fast food packaging and packaging fillers when items are bought on-line and delivered in cardboard boxes.

One way to reduce our impact on the planet in terms of forest destruction, land degradation, pollution, atmospheric carbon and its affects on global warming would be to reduce our usage of paper so that even fewer forest are clear felled. Recycling paper is helping the planet by reducing the impact on our forests.

Why do we recycle paper?

4 Answers4