大象传媒

Biodegradable bags are well and good for carrying merchandise home from stores, but how are we going to dispose of our waste? It's difficult not to conclude that the push is coming from a variety of green whose ideal world involves reverting to a preindustrial lifestyle.

Plastics aren't evil, they're recyclable.

In a short time we'll be mining our own landfills for reusable materials; the mistake the Left makes on this issue is to assume that only some form of coercion or infringement is the right thing to do in the meantime.

Am I the only one who turns around and uses the plastic carrier bag from the shop to put in my small trash bins?

One more example of environmental nuttiness. Plastic is a miracle material, one of the most versatile ever created. There may be more different kinds of use for plastics than any other material known. Our entire civilization depends on plastics in more ways than you can count. Much of the computer you are now using is made largely out of plastic including the keyboard, the mouse, and in many cases the screen. The semiconductor chips which operate your computer are encased in plastic. So are the wires.

The alternative to plastic bags is a return to paper bags. These are biodegradable and will break down into CO2 among other things. Plastic bags do not break down and can last for thousands of years. They generate no CO2 after they are disposed of unless they are burned. Manufacturing paper bags requires cutting down forests and probably consumes far more energy to manufacture per bag and therefore creates more CO2 to make than plastic. It is also host to many pests like cockroaches which feed on paper pulp, infest homes, and spread disease. No thanks, I'll stick with plastic. I like the 21st century, I'll leave the 19th to others.

Re #3

The alternative to plastic bags is a return to paper bags. These are biodegradable and will break down into CO2 among other things.

And the point is?

Plastic bags do not break down and can last for thousands of years. They generate no CO2 after they are disposed of unless they are burned.

And the point is?

Manufacturing paper bags requires cutting down forests and probably consumes far more energy to manufacture per bag and therefore creates more CO2 to make than plastic.

In the manufacture of paper bags more trees are planted by the paper companies than are cut down. CO2 is reduced. And again your point about CO2 is?

It is also host to many pests like cockroaches which feed on paper pulp, infest homes, and spread disease. No thanks, I'll stick with plastic. I like the 21st century, I'll leave the 19th to others.

In your house maybe - can't say I have this problem myself.

Regards,
Michael

John, I don't think alot of the greens want us to go back to a pre-industrial era, I think they just recognise that we are moving in to a post industrial era. And the end of oil is going to mean huge changes in our daily lives. How we manage these changes is the key question.
The technologies that are going to bridge the gap to the post oil economy are developing fast - but the changes we are facing are vast and there will be some necessity to mangage the resources we currently have. So like it or not - government will have a role in this - as they did with rationing in the second world war.

DP makes a good point. We will only have cheap oil for a few more years. Society as a whole need to start looking for alternatives to fossil fuel based products were practicable. I find it hard to be believe those people who seem to be ideologically opposed to using a paper bag. Wackos.

Michael N. Hull #4
For someone who said he has a background in chemistry, you disappoint me.

"The alternative to plastic bags is a return to paper bags. These are biodegradable and will break down into CO2 among other things."

"And the point is?"

And the point is that after paper bags are disposed of, they are either broken down by bacteria or incinerated, either way generating more CO2 into the atmosphere. Recycling them if it's possible also generates more CO2. Plastic bags sent to a land fill do not generate more CO2, bacteria can't attack them and can't break them down.

"Plastic bags do not break down and can last for thousands of years. They generate no CO2 after they are disposed of unless they are burned.

And the point is?"

Less CO2 resulting from the use of plastic bags instead of paper bags if the plastic bags are not burned.

"Manufacturing paper bags requires cutting down forests and probably consumes far more energy to manufacture per bag and therefore creates more CO2 to make than plastic."

"In the manufacture of paper bags more trees are planted by the paper companies than are cut down. CO2 is reduced. And again your point about CO2 is?"

Not only is more CO2 generated in the manufacture of paper bags than plastic bags considering the processing of trees, manufacture of paper, forming into bags, and greater weight for a given size bag, but between the time the trees are cut down to make the bags and their replacements fully mature, the CO2 the trees would have converted to sugars and oxygen by their chloroplasts will not happen. The process of maturation of new trees will take many decades, 50, 75, even 100 years. The loss of absorption of CO2 out of the atmosphere during that time has to be added to the computation of the difference between them. Using paper instead of plastic adds to global warming, it does not decrease it.

"It is also host to many pests like cockroaches which feed on paper pulp, infest homes, and spread disease. No thanks, I'll stick with plastic. I like the 21st century, I'll leave the 19th to others."

"In your house maybe - can't say I have this problem myself."

Roaches brought into supermarkets in any of the countless thousands of different kinds of product which pass through them to consumers find paper bags as a way to enter people's homes because roaches eat the cellulose in them and lay their eggs their. In most major cities, most apartment buildings are infested with cockroaches, often brought in this way. Once infested, it is very difficult for an exterminator to eliminate them and re-infestations are common. Owners of private homes are equally vulnerable although eliminating an infestation is usually much easier.

If you ever have a liquid spill inside a paper bag, especially if it is the result of a broken glass container, you will wish it were plastic instead. Unless punctured, most plastic bags supplied by supermarkets are water tight and do not lose their strength when wet. Often, containing the spill means nothing more than removing and drying the undamaged contents of the bag and disposing of it liquid, glass, and all still in the bag. If the same happens in a paper bag, you are soon confronted with a leaky mess and dangerous broken shards of glass.

Using paper instead of plastic bags by supermarkets IMO is a very dumb idea. The one value brown paper bags have is to accelerate the ripening of certain fruits left in them at room temperature like peaches, plums, apricots, nectarines, and pears. In the US, these are usually harvested, picked, and sold slightly unripe to avoid damage prior to sale during shipping and while on display in markets.

Paper vs Plastic bags.
Here's an idea - neither !
Whats wrong with using strong re-usable shopping bags ?

Re #7

For someone who said he has a background in chemistry, you disappoint me.

Can't say that I care about that. Don't let it spoil your Thanksgiving turkey!

However, I see now where your were going with your fixation on CO2.

What has anthropogenic CO2 got to do with global warming? Zero as I read the evidence!

Quotes from above discussion:

1) Over the past half-million years a rise of CO2 concentration did not precede the changes in air temperature but followed them. The rise in global temperatures could not have been caused by CO2 but rather the reverse was the case.

2) Antarctic ice cores show that rises in levels of CO2 have lagged 800 years behind temperature rises at specific times in the geological past.

3) Correlation is not the same as causation. Just because CO2 and temperature rise are correlated does not mean that one is a cause of the other. The medical profession and the news media constantly fall into this trap. How many times have you heard that a study has been conducted of the people who suffer from breast cancer and it has been found that increase in breast cancer is related to a high consumption of something like bananas? It鈥檚 all baloney. Newark has more synagogues than Salt Lake City and the crime is higher in Newark. So is the higher crime rate caused by the presence of synagogues? The correlation is certainly there, the causation is NOT.

4) About 3% of the CO2 in the atmosphere is anthropogenic; 97% comes from natural sources.

5) The Earth receives as much energy from the sun in one hour as Man produces in one year.

6) The output of the sun's energy varies on numerous cycles one of which is the eleven year sunspot cycle.

7) Projections and Predictions are totally different and vastly misunderstood terms. When we place inputs into a computer model we get an output which can be extrapolated to make a 'projection' based on the model's inputs. Unfortunately, the media and the global warming alarmists take these computer projections and refer to them as 'predictions'. Projections are always accurate - the computer has just calculated something based on what you gave it. But to refer to the projection as an 'accurate prediction' is stupidity gone mad.

8) One argument is that increased solar radiation is warming the earth. This radiation may also cause the oceans to release some of the CO2 that has naturally been absorbed there. As water temperature rises the solubility of CO2 in it decreases. So the majority of the build up of CO2 in the atmosphere is not driven by human activity but is driven by the sun鈥檚 activity. Now as the sun drives CO2 out of the seas, this CO2 can indeed act as a blanket trapping heat in the earth鈥檚 atmosphere and magnify the warming of the earth beyond what would occur in the absence of a CO2 鈥榮ink鈥� in the seas. Also as things warm up white stuff melts and the reflectivity goes down (more heat absorbed). It is not surprising that once a warm period begins that the warming accelerates. The same thing will happen in reverse in millions of years when the process reverses and we enter the next ice-age. So a 鈥榗ause鈥� of global warming might likely be an increase in the radiation output from the sun which has the effect of causing an increase in warming and CO2.

Regards,
Michael

Michael #9
I didn't want to turn this into a debate about global warming and GHGs. I'll say that initially I was very skeptical about it. But recently seeing photographs of the Columbia Glacier in Prince William Sound, having seen it first hand in 1988 and seeing photographs of the Polar Ice Caps along with other receding glaciers around the world, it seems to me that a good case can be made for global warming. I'm not wholly convinced CO2 output is the cause, there are still respected scientists who disagree that CO2 output is causing global warming and who argue that CO2 is lagging temperature rise and is a consequence of it, not leading it.

However, it also seems to me that a majority of scientists say GHG emissions including CO2 are driving global warming and they have computer driven mathematical models which track it fairly well. I'll continue to follow the debate with an open mind. This is not a purely academic matter. If they are right and we don't do something, we face massive dire consequences to humanity. And if they aren't right but we take drastic actions to reduce CO2 emissions by 60% to 80% we face massive dire consequences to humanity also.

BTW, because CO2 is a naturally occurring component of the atmosphere, I do not consider it a pollutant, that鈥檚 an irrational and pejorative characterization by many IMO.

Re #10

Mark: We seem to be on the same page. Just be careful of those mathematical models and the difference between projections and predictions.

Regards,
Michel

Re #10

Re the definition of a 鈥榩ollutant鈥�. I think if something is out of its 鈥榥ormal鈥� range and becomes harmful one might speak of it as 鈥榩ollution鈥�. For example, in horticultural circles one defines a 鈥榳eed鈥� as a 鈥榤isplaced plant鈥�.

But given that I don鈥檛 think the present CO2 levels are out of historical ranges (it has been 4-5 times higher in past geological times) it probably can not, as you point out, be considered a 鈥榩ollutant鈥�.

Regards,
Michael

Hello Mark, Michael,

Reducing CO2 output is always a good idea, even if you're not convinced that it causes global warming. The burning of fossil fuel not only produces CO2, along with it come SO2 and NOx. These are pollutants in probably anyones book. So using less fossil fuel is good, even if not for the reason held up by most.

Btw, going back to the original topic of this thread, I usually use the 'one time' carrier bags something like ~5 times before the holes in them become too large for them to be of any use anymore. Is that not the easiest way to cut down the number of bags used by 80%? The effort to bring last times bags is not a huge one.

And does anyone know the absolute plastic weight in shopping bags and bin liners sold? The percentages William quotes are less useful. If the original volume of bin liners was very small to start with, then that 400% increase doesn't mean much in absolute terms. Does anyone know?

greets,
Peter