Friday, January 23, 2009

Trees or Whales?

Earlier this week I needed to run into a local grocery store to pick up some food for the little one. It was supposed to be a quick pop-in to grab a couple of things, but once I was there I grabbed a bunch of junk that I have been putting off. So, inevitably, I ended up with a cart full of pantry items. This is easy to do at the Vitamin Cottage – all organic produce, free range buffalo, sustainable personal care items – you know, some good hippy, earth-saving, tree-hugging shit. Anyway, at the checkout line I was waiting for the ubiquitous question that everyone always gets asked, “Didn’t I see your picture in the post office?” Alright, that’s not the one I was initially thinking of, but I do tend to get asked that a lot. Anyway, the real poser that is so oft heard at the checkout line is of course, “Paper or plastic?” However, this time I wasn’t even given the choice. The dred-bearing baggist just started happily loading my items into a paper bag. Naturally, I asked, “Why are you guys going with paper now?” His reply was, “We’re leaning away from plastic bags because they are like soooo bad for the environment.” I immediately thought, The deodorant is just one isle over. Would you like me to instruct you on its proper use? Then I thought, Really? Is paper better than plastic? We’ll see about that, Hippy.

First of all, let’s get our terminology straight. These are grocery bags NOT grocery sacks. Sack is such a crappy word that I here-to-fore ban it from our discussion. Besides, there’s something gross about putting your food in a sack. Anyway, there is a wealth of information on this bag subject available on the web, but it seems like the prevailing political wisdom is going in the direction of paper. Score one for the pulp lobbyists. Many large cities, including San Francisco, have put in place laws restricting plastic bag use, and some countries have banned them altogether. Why? I don’t know, but we’ll find out together, won’t we? Turns out that the main reason (besides a perceived backlash against the oil industry) is that plastic bags are a litter problem especially along the coasts where marine wildlife gobble them down since they look like jellyfish in the water. This seems like more of a trash containment issue rather than an environmental issue to me. Let’s do a quick side-by-side comparison of the two types of single-use bags that are most-often used based on their overall environmental impact and energy consumption from cradle to grave.

Plastic bags are made out of polyethylene which can be produced from a byproduct of the oil refining process, as most plastics are. It can also be made from natural gas which we have an abundance of in the U.S., but it is still a non-renewable resource. Most of the grocery bags used in the U.S. are plastic. This adds up to about 100 billion bags per year in the U.S. alone or about 1500 per household – 4 per day. That seems like a lot to me, but I don’t tend to use them very often. It takes 12 million barrels of oil to make that equivalent number of bags. This is enough bags (when compressed) to pack an indoor football stadium full to the roof. They would wrap around the world 1625 times. Only about 3-5% of the bags we use get recycled, but it’s a bad idea anyway since it costs around $4000 to recycle 1 ton of plastic bags which will only return ~$30 worth of material to the market. You do the math on that one. Don’t get me started on recycling. It takes ~.5MJ of energy to produce one plastic bag. Also, plastics do not biodegrade. They can photodegrade over time (like 1000 years) if exposed to enough sunlight. I think it’s interesting if you look at plastic’s environmental persistence this way – every piece of plastic that has ever been produced (and hasn’t been burned or recycled) still exists…somewhere.

So far it’s not looking good for our plastic selection, so now let’s take a look at paper. We use about 10 billion paper bags in the U.S. annually. It takes 14 million trees to feed that beast alone. That’s 700,000 tons of paper bags – roughly the same mass as 10,000 average American houses. Once the trees are cut down, they are essentially ground up, boiled in sulfuric acid, washed and bleached, then pressed and rolled. This is hugely energy and chemically intensive. The process is a pollution nightmare, and we end up with a global warming double whammy. The pulp plants consume energy and produce carbon dioxide, and trees that sequester the CO2 are cut down to make the product. The recycling process is just as bad. It takes about 2.6MJ of energy to produce one paper bag. That’s enough energy to run your washing machine for two days straight.

Where does that leave us in our side-by-side comparison? Well, it takes almost five times more energy to produce paper bags than it takes to produce plastic. The production of paper bags creates 70% more air pollution, and 50 TIMES more water pollution than plastic. Paper bags take up about five times more space in a landfill. It takes 98% less energy to recycle a pound of plastic versus a pound of paper, and it takes nearly twice as much fossil fuel to make, deliver, and distribute paper. It takes one gallon of water to make a single paper bag, whereas it only takes 10 tablespoons to make a plastic bag. As far as the whole issue of paper being biodegradable goes, that dog doesn’t hunt, either. Landfills are not designed to allow garbage to biodegrade. Quite the opposite is true, actually. Landfills are a huge, sealed storage drum where over 95% of the trash is covered by dirt so air and sunlight can’t get to it which makes biodegradability a non-issue. I may write more about landfills later. While we’re on the topic, “biodegradable” plastic bags are essentially 2 to 3 times worse in every category than regular polyethylene bags. Besides, even the biodegradable plastic bags don’t actually biodegrade. They just basically fall apart into smaller plastic pieces over 50-100 years which is plenty long for a dumb-ass whale to mistake one for dinner.

So it looks like the cheapest solution is the winner here. The villain is the hero. Any decision to ban plastic bags in favor of single-use bags made from alternative materials will be environmentally counterproductive and wasteful on every front. The litter issue will always be there because people are slobs, and garbage companies are mostly apathetic. If we were able to increase recycling and reuse rates of plastic bags (and decrease cost of the recycling process) and increase the efficiency of the pimply-faced baggers at the checkout counter so they can fit more into one bag, the environmental impacts of these ubiquitous bags would be even further reduced. It would seem that the initial knee-jerk reaction against those poor little bags is unfounded in logic (it may be somehow founded in public opinion which I don’t understand and is certainly not logical). Personally, I have a bunch of the reusable canvas bags that are possibly the best solution, and when I only have a couple of items I request no bag at all. So, next time you are asked the question, “Paper or plastic?” reply, “Plastic, of course! It is much better for the environment.” Then take a look at their faces, and tell them Daniel P. sent you.


TJ said...


I think this is my favorite blog of yours yet, and you've had some winners. I salute you. You should link it on Facebook.

Dan said...

Thanks, TJ. Just made the Facebook link. First time I've tried that. Brilliant!