After hearing people argue over the environmental costs of "paper"
versus "plastic" during my lunch hour, I'd like to understand the
relative environmental costs of plastic grocery store bags versus
paper grocery store bags.  So far, I have the impression that, all
things considered, plastic bags are significantly more detrimental to
the environment than are paper bags. For example, plastics are piling
up in the world because they are extremely slow to biodegrade. 
Plastics have become a large percentage of the diet of wildlife ?
frequently to lethal effect. However, I've also heard the argument
that the process of making paper is much worse than the process of
making plastic with regards to environmental degradation. I'd like to
better understand the impact of plastic bags as well as the impact of
paper bags.

Hello brian22:

Thanks for the great question. I like to think of myself as
environmentally conscious, so this question has always interested me
as well.

There is a cartload of information available on the "plastic vs.
paper" bag debate. I've tried to find you a cross-section the most
non-partisan, objective information I can (i.e., data not from the
plastic or paper industries).

The overall conclusion that I've drawn from reading through all this
information? NEITHER plastic or paper is better than the other. They
both have their pros and cons. Plastic is less polluting to produce
and compacts to a smaller space in landfills. Paper is more often
recycled and doesn't choke wildlife (especially birds). Almost all
sites that I went to recommend that the optimal solution is to buy
reusable (cotton) bags or to re-use the plastic/paper bags you already
have.

However, that brief summary doesn't speak to your scientific concerns
about environmental impact of the two choices. Please read through the
webpages listed below for more detail. I've extracted some relevant
passages, but I think it would be a good idea to read through them
more thoroughly.

U.S. Environmental Protection Agency
"Questions About Your Community: Shopping Bags: Paper or Plastic or . . .?" 
URL: http://www.epa.gov/region1/communities/shopbags.html
Quote: "Did you know plastic grocery bags consume 40% less energy to
produce and generate 80% less solid waste than paper bags? Did you
know plastic bags can take 5-10 years to decompose whereas paper bags
take about a month to decompose?...There seem to be pluses and minuses
on both sides of the debate. For paper bags, the life cycle stages
consist of timber harvesting, pulping, paper and bag making, product
use and waste disposal. For plastic (polyethylene) bags, the steps
involve petroleum or natural gas extraction, ethylene manufacture,
ethylene polymerization, bag processing, product use and waste
disposal. In all of these steps, energy is required and wastes are
generated."

treehugger
"Q&A: Retail Carry Bags - Paper or Plastic?"
URL: http://www.treehugger.com/files/2005/01/qa_retail_carry.php
Quote: "Hey Elias, good question, with an easy answer. Neither. Both
are bad. However, strange as it might seem, plastic wins the number
crunching to beat paper, two to one, in Life Cycle Analysis (LCA)."

Institute for Lifecycle Environmental Assessment
"Paper vs. Plastic Bags"
URL: http://www.ilea.org/lcas/franklin1990.html
Quote: "Franklin and Associates completed a life-cycle energy analysis
comparing the two common grocery bags. There were two critical
measures. The first is the total energy used by a bag, which includes
both the energy used to manufacture a bag, called process energy, and
the energy embodied within physical materials, called feedstock
energy. The second measure is the amount of pollutants produced. Using
energy and pollutants from all stages of a bag's life, both measures
result in favor of plastic bags."

reusablebags.com
"Paper Bags Are Better Than Plastic, Right?"
URL: http://www.reusablebags.com/facts.php?id=7
Quote: "The answer to the ?paper or plastic?? dilemma is: Neither.
They?re roughly equal in pros and cons. While convenient addictions,
they both gobble up natural resources and cause significant
pollution."

If, after you've read these four articles, you still feel the need for
further information, please let me know the details of what you want
in a Clarification Request.

Search Strategy (on Google):
* "plastic bags" "paper bags" environment
* "plastic bags" "paper bags" environment site:.edu
* "plastic bags" "paper bags" site:.org

I hope this helps.

websearcher

Thanks!

plastic bags are made from oil-based products.. and the way oil is
going id stick to paper, we can always grow more trees, but we cant
wait 100,000 years for more oil.

...or we can stop using petroleum and start using vegetable oil for
cars, or liqiud hydrogen in the form of fuel cell, or put paper bags
over our heads and parade around downtown offering our services to
carry people to and from work for the same amount a barrell of oil
costs... wait, how much is a barrell of oil?

As a Green Engineering Practioner, PAPER is overwhelmingly preferable.
 The lignin extracted simultaneously from the wood chips is burned in
a Black Liquor Recovery Boiler which supplies all of the energy and
steam for ALL mill operations and, often has surplus energy to sell
back to the grid.  Lignin is the black stick stuff in the tree that
allows it to stand up.  SO . ...

Two tons of wood chips produces a ton of pulp which is then used to
make paper AND a ton of lignin, which is then used as a fuel
generating both steam and electricity.  These processes are
interdependent and cannot / do not occur as separate operations as
seen with other processes.  Since mill integrated operations, energy
requirements and support utilities are all at one facility ? separated
yet fully integrated with piping / automated systems ? the economic
and environmental impacts of handling, transportation, container
residual, etc., often of concern within the new chemicals process, is
eliminated.  To put quite simply, a piece of paper made from this pulp
that you hold in your hand has already generated its mass in a green
fuel.  The more paper that is made, the more of this green lignin fuel
is generated as a byproduct, which in turn generates electricity and
steam.

Coincidentally, I have been doing a green engineering assessment on
this very thing, as it is a most illustrative example, as this has
evolved, continues to be the plastic vs paper bag comparisons and all
previous studies showing how this is a wash.  Or so I thought.  I must
admit I was very dismayed at the inaccurate statements on this which
seemingly are based on a single study - which did not take lignin /
lignin fuel into consideration.

The simple choice of getting a paper bag versus a plastic bag at the
grocery store gives you at least a double impact on our dependence on
fossil fuels and related environmental impacts of using them.  First,
you are replacing an oil based product (plastic) with a chemical pulp
based product (paper).  Second, you are replacing a coal fuel (and a
coal utility and all associated environmental impacts) with lignin
fuel (which is a byproduct of the wood pulping process).

To truly equate these environmental impacts and benefits, one should
compare the unit operations occurring within the integrated paper mill
(which include debarking&chipping, recovery boiler loop, pulping,
brownstock washing, delignification/bleaching, several papermachines,
converting, utilities, waste treatment), to the comparable operation /
operations with the plastic manufacturing process, which occurs in 7
or more different operations.  For example, the input / output streams
of the black liquor recovery boiler system should be compared to coal
mining, milling, and utility operations.  And the transport, equipment
and handling costs of getting the materials to these different
operations.  So the above single box operation, in which a truck full
of logs literally pulls into the mill and the final paper product
comes out, and at times with a NET energy surplus, would be compared
to the cumulative effects of all processes involved to make the
plastic (oil based) bag as well as the processes to generate the
energy (coal utility boiler) to support these processes.

My local grocery store has a bin for the recycling of plastic bags. It
would be interesting to know how the plastic bags get recycled, and
how much that (if done widely) could affect the paper vs. plastic
debate.

Dear Treelingual-ga,

That sounds wonderful, burning lignin to power paper mills, and I have
seen some sites that discuss the subject, but I am still very doubtful
that this can really supply all the energy needed to run a paper mill.

Can you provide a website that documents this?

Thank you, Myoarin

Dear Treelingual-ga,

I am a student preparing a persuasive speech on this very topic of
paper versus plastic and would absolutly love to see where you got
your information. Can you post a website or something? Thanks

Brian, I have been doing research and so far I have not found a
definite one over the other.. (seems to lean towards paper??) so far
it seems like the most popular answer is not to really figure it out
and take a cavanas bag to the store instead of plastic or paper.

My information is not from a web site but based on 2 decades of
experience in the pulp and paper industries (private) and currently
managing the green engineering program at EPA.  (google under
greenengineering one word my site 1st and 2nd listed)  There is not
information on this site, though.  For the last 7 years we have been
developing academic materials, textbook, etc.  This is first focus on
industrial process and am approaching current work as a green
engineering practitioner - as it is a philosophy, an approach.

Another misconception, which i started with, is Too Bright Paper is
Not Too Bright.  we currently overbleach to an appearance target -
brightness - where the paper performs fine at <1% lignin, potential of
eliminating two bleach plant stages with a slew of benefits, including
32% in energy and steam, ClO2, AOX, BOD reductions, etc.  All
achievable without capital equipment costs.

I have just started this more detailed, green enginering assessment
taking into consideration - which has not been before, even and
especially in regulations (that i have been looking at most of the
day! :-))  burning the black liquor from the pulping process, which
would have to be dealt with in some manner or other, in a recovery
boiler @ a rate of 15,000,000 BTU / ton of pulp and utilizing that as
the primary energy source.  There are some power boilers in the mill
which use bark and petroleum fuels, and LPG is needed in the lime kiln
(@ 2,000,000 BT / ton of pulp) which is in the liquor recovery loop -
just one additional place where the industry utilizes HEN (Heat
Exchange Networks) and MEN (Mass Exchange Networks).

Bottom line question:  Could you run your plant if the grid shut down?
A chemical pulp mill can.  

Other points:
*  bleaching (heat) and papermaking process (condensate for dryer
cans) utilize the steam coming out of the boiler, and out of the
turbine.  Electicity is just a side product.  Thermodynamic
standpoint:  There is a 40% conversion going from fuel oil to
electricity, you do not experience that loss using the steam.  Crude
oil to fuel oil efficiency is 90%, a processing step that is not
needed with pulp.  A very ENERGY intensive, waste producing process. 
Another energy loss:  electrical energy to mechanical energy is 40%
conversion.  Still using the steam . ..
 *  CO2 releases:  crude oil -> fuel oil, ethylene process, and
ethylene polymerization, all steps required to get to the raw material
needed for the plastic bag (unlike paper and pulp) are all EXTREMELY
energy intensive, pulling from the GRID as well as consuming fuels at
the facility to run crackers, distillation columns, etc.  Crude oil to
fuel oil alone requires temperatures up to 424 degrees (f).  In
addition, additional energy is spent on processing / cooling these
streams.  All of these additional energy requirements, at all of these
different manufacturing facilities are met by burning fossil fuels
generating significantly more CO2.
*  Energy generated to separate water / oil streams.  water / oil
waste water streams generate water / benzene mixtures, regulated by
RCRA.
*  VOC, SOx, NOx all significanly higher for plastic, as double
contribution utilities and process releases.  The feedstock is a
petrochemical, ethylene is a VOC, actually is rates as a Highly
Reactive VOC (HRVOC), identified as a subset that when formed by NOX
form greatest level of ground level ozone.  Whole new subset of
regulations done on this topic in Texas.  Dr. David Allen was the
Technical Lead for Texas Air Quality Study, largest ever, and leading
efforts in this area.  He is also the primary author of the green
engineering textbook and continues to champion Green Engineering
approaches in Texas through this work and as a chemical engineering
professor at Univ of Texas, Austin.
* Many of these Criteria pollutants from refining / plastics / and
coal utilities are of acute and chronic concern, several being
carcinogens.
Oh - and the plastic bags collected?  All go to China!  We send them a
lot of our paper, too, or should i say, they buy it from the trash
haulers that pick up what you recycle!  Without that - they would not
be able to make paper, cause they don't have trees and they don't have
black liquor recovery boilers even if they can get the trees from
someplace else!!

Interest in this topic continues to be of interest to me as I continue
my treasue hunt here of finding more and more benefits of the simple
paper bag! It really IS a Slam Dunk!

TreeLingual   :-)  :-0

Treelingual,
Thank you for the additional information.  Living in Germany, where
GREEN is big, recycling everything:  paper, plastic, glass( white,
green, brown), etc., I am surprised that there has been no mention of
what you are discussing.
It still sounds rather theoretical to me.  Sorry to be so sceptical.
Myoarin

Myoarin - 
It does sound too good to be true.  It is how the process evolved,
first boiler being built in the 1930's.  So i have run into some brick
walls in now having it adequately counted / represented.  It is a
byproduct of the pulping process so not equated as a 'separate' energy
source.  But you do have 96 of these black liquor recovery boilers
operating in the US producing and buring 1140 tons of lignin every
single day.  So we are generating it and using it.  Just that the
industry is not getting the 'credit', for lack of a better word.

Hopefully more and more will be talking about this - which is why i am
crunching some numbers.

Just know that when they cook wood chips to get the pulp, they get as
much in lignin and need to do something with it.  Dispose of as a
waste stream?  they could.  Burn and recovery and recycle - makes more
sense and is what they do.  Should they not get credit just because
they have been doing it this way before a life cycle assessment even
existed?

Thank you so much for more information Treelingual-ga. It is kinda
discouraging to try and do reasearch, since everything seems to not
take everything into consideration and wants to push plastic. I really
appreciate your time.

Treelingual-ga,
Thanks for keeping after me.  It sounds to good to be true but this
site helped convince me:

http://www.westbioenergy.org/lessons/les16.htm

Keep up the good work!

Myoarin

Thank you all for the encouragement and the additional information.  I
have not had a chance to read through the Camas mill materials, but
have been to that facility and it is one of my all time favorites.  It
is just located in a very beautiful part of the country and strives to
blend well with its neighboring community - where many that work in
the mill also live!

I also appreciate how discouraging it can be when you are trying to
get some specific answers and receive generalities - sometimes slanted
generalities.  There is a certain amount of conditioning which makes
it difficult to communicate the message.  So we will put specific
numbers on it, irrefutable, until it is obvious to everyone.  And if
the result is that more paper bags are selected at the grocery store
(right now it is 80% Plastic), or more white and brown paper being
recovered, collected and directed back towards these mills, thereby
producing even more paper using the same if not slightly more energy,
then the country will benefit as a whole.  Because these actions will
replace fossil fuel use and reduce CO2 global warming gases.  Small
sacrafice - not even asking one to give up their big SUVS sporting
yellow ribbon magnets.

Any input and additional information on this subject will be useful in
this quest.  Thanks!

TreeLingual

Treelingual,
I better go back and read that site myself, now that it has your recommendation.
I probably would have dropped the subject if my dad hadn't been a
forester for a paper company - which in those days was certainly no
saver of energy, air polution.
As employees used to say:  It smells like bacon and eggs.
Well, more like rotten eggs.
Good luck, Myoarin