us and the environment

The question we get asked most often is “are your bags biodegradable?”. You would think there would be a simple answer to this question, but the answer is more complicated than most people imagine. For example, the location where something degrades can determine what it turns into. Our bags are oxo-degradable, which means that above ground, in the presence of oxygen and sunlight they degrade to carbon dioxide and water at a similar rate to cornstarch bags. However, we have chosen to use oxo-degradable bags, not because of how they degrade above ground, but how they behave below ground. Because the reality is that the vast majority of dog poo bags end up in landfill. And in offering a product, we believe our responsibility extends beyond the point of our bags being placed in a rubbish bin. This is where things become more complicated. Because when you place biological material in a landfill, it can be very bad for the Planet.

Here is an explanation as to why we use HDPE (high density polyethylene) bags rather than cornstarch. In an ideal world, everyone would have a compost heap in their back yard. Unfortunately, there are reasons why most people don’t attempt to compost dog poo. And it’s not just lack of space, laziness, or the ick factor. Dog poo contains pathogens and if not handled properly can spread nasty diseases around the neighbourhood. In order to kill these pathogens, a temperature of 60 degrees Celsius needs to be achieved and maintained. This means your compost heap requires constant attention. If you presently use cornstarch bags for dog poo pick up and they are not breaking down quickly in your compost heap, it is probably an indication that optimum temperature is not being maintained, because cornstarch also requires prolonged temperatures of 60 degrees in order to breakdown. If not composted, a cornstarch bag takes around the same amount of time to break down in the environment as an HDPE bag (between 12 to 18 months on land – longer in seawater).

So, why do we use HDPE rather than cornstarch. The answer is that presently, because of all the above, the vast majority of dog poo bags end up in rubbish bins and go to landfill. If you landfill a cornstarch bag, it will eventually break down. Unfortunately that is not as good as it sounds because, due to the absence of oxygen, the bag and its contents will degrade anaerobically. This produces methane, which is terrible for the environment. It has an atmospheric heating capacity 30 times that of CO2. So, landfilling a poo in a cornstarch bag increases its effect on Global Warming by 3,000%. Using an HDPE bag (which is impervious to water, essential for the degradation process) sequesters the carbon contents of the poo, taking it out of the carbon cycle. Landfilling is an emotive issue, but for the foreseeable future, some of our waste will continue to be buried. However, the first thing we should be removing from our landfill waste stream is biodegradable material because, if it degrades there, every last scrap of it turns to methane. So if you want to offset your pet’s carbon footprint, buy a green waste bin which is collected by a commercial composter. You can save up to 4 tonnes CO2e per household per year by diverting all your green waste and kitchen scraps to commercial composters. Unfortunately, one of the things they won’t presently accept is dog poo. So, in the meantime, if you don’t have a home compost bin, we recommend you continue to use HDPE bags.

HDPE is the same material used to make the thin walled supermarket bags that have recently been banned. Since our bags are made of the same material (as are most dog poo bags sold in New Zealand), you might be interested to have a little more information about HDPE.

Every human alive has an effect on our Planet, and we each have a responsibility to keep our individual environmental footprint as small as possible. This is made more difficult when we do not have access to accurate information about how to do this. In the developing world, there is a very real problem with plastic pollution, but in the developed world, our contribution to environmental pollution comes almost entirely from our greenhouse gas emissions. It is critical that we understand the difference.

Special interest groups within the environmental movement decided they needed a rallying point in the fight to save our Planet and chose “single use plastic bags”. We believe in doing this, they have taken the focus away from some very simple, unglamorous, and yet, very important things that we in New Zealand could be doing to reduce our greenhouse gas emmissions, and help save our Planet from the greatest threat we have ever faced. That threat is Global Warming.

Many misconceptions circulate on the internet about “single use plastic bags”. Before banning them, it would have been useful to have a more balanced discussion as to their relative merits and drawbacks.

Misconceptions about single use plastic bags:

"Plastic bags clog up landfills"

Modern landfills do have a problem. A massive problem. They produce greenhouse gas. Lots of it. Globally landfills are responsible for around 11% of all man made methane emissions (New Zealand's total annual landfill methane contribution is almost 4,000,000 tons CO2e). And methane is a very potent greenhouse gas. Its warming potential is around 30 times that of CO2. Methane is created by the anaerobic (without oxygen) breakdown of biological materials in landfill waste. Biological material consists of things like wood, paper, garden waste and food scraps. It constitutes a staggering 64% of our domestic waste. It is this biodegradable material that is causing the problem, not the inert waste. If the food scraps you scrape into your rubbish bin produce 4kg of CO2 above ground, in the landfill, the methane produced has an equivalent warming potential of 120kg of CO2e.

Ironically, HDPE bags can prevent the production of greenhouse gases in landfills by preventing water (essential for anaerobic degradation) from getting to the biological material. So biodegradable material, secured tightly in a plastic bag can not only be prevented from turning into methane, its carbon content can be trapped in the landfill forever, taking it out of the carbon cycle. This is known as carbon sequestration. You will be hearing a lot more about carbon sequestration over the next few years because we have already pumped too much carbon in the atmosphere, and we need to find ways to reduce it by taking carbon out of the carbon cycle. When you landfill an HDPE bag containing biodegradable material, the plastic that came from crude oil pumped up from underground, is returned underground and takes with it, yet more carbon.

"There are better options than plastic bags, like paper, jute and cotton"

From a Global Warming perspective, this is not true. Paper production is energy intensive and highly polluting. Paper cannot be infinitely recycled (a maximum of 4 times until the fibres become too short to bind to each other). Eventually, unless it is burnt, all paper will end up in a landfill where it will produce methane. Similarly when cornstarch bags end up in a landfill, which the vast majority of them will, they create methane. Plus any organic matter they contain will then be exposed to water and will also turn into methane. Jute has a high water requirement which limits its production. It also turns to methane in landfill. A cotton tote bag with an equivalent carrying capacity has a Global Warming Potential of 327 “single use plastic bags” (you can find more information on this further down the page)

"You can't recycle soft plastics"

Actually, until recently you could, by returning it to your local supermarket. This soft plastic was then collected by an Australian company that recycled it into items like bollards, park benches and walkway tread that could be purchased by Councils instead of using arsenic treated timber. Unfortunately, not enough Councils got on board with this to use all the recycled plastic coming from New Zealand, so the Australian company stopped accepting our soft plastic. Soft plastic makes up a lot of what you buy at the supermarket (from frozen pea packets to biscuit wrappers, and everything in between), if you could still buy plastic bags you would notice that they accounted for just a tiny fraction of the total volume of the soft plastics you collect during a week’s shop.

"Plastic bags are made of toxic chemicals"

There are many types of plastic, but when we discuss them we seldom differentiate between them. Some plastics are toxic, some are not. PVC, polystyrene and polycarbonates are three examples of the former. They contain aromatic hydrocarbons which are dangerous to humans.

Single use plastic bags are made of HDPE. This is a very pure compound made up of just carbon and hydrogen in a linear chain. It is not toxic. Its basic building block is ethylene (this occurs naturally in plants). To produce HDPE, ethylene is formed into long chains, which are very stable. HDPE can be burned. This produces carbon dioxide and water.

"Every piece of plastic ever made is still with us"

This well-worn phrase is not actually true. Plastics eventually degrade to smaller molecules (mostly carbon dioxide and water). Their speed of degradation is dependent mainly upon the wall thickness of the product they are made into.

"Plastic bags take a hundred years to degrade"

Thin film HDPE is an engineering miracle. With a wall thickness of less than the width of a human hair, an HDPE bag can easily hold one and a half thousand times its own weight. Pound for pound this makes them an incredibly efficient product. The long carbon chains in HDPE not only make it very strong for its weight, they also make it hard to break down. Having said this, there are organisms in the environment, both bacteria and fungi, that can metabolise it. It is not dissimilar in its chemical composition to bees wax. Modern production of HDPE uses additives that form weak points in the carbon chains, that react with sunlight to break the chains down into much shorter lengths. So, above ground (in the presence of UV light), it begins to degrade quite rapidly. This is helped by the fact it is a thin film (around 13 microns in thickness). The smaller the pieces become, the easier it is for microbes to digest them. It can't get into our food chain, because if ingested by an animal, it can't pass from the animal's gut to its tissue. When degradation is complete (called mineralisation), the two chemicals you end up with are CO2 and water.

"Huge numbers of plastic bags end up in the environment and cause pollution"

Many countries, especially in third world, have poor or non-existent waste management systems. A recent scientific study has concluded that up to 95% of all oceanic pollution originates from 10 large rivers of the developing world. This does not mitigate our responsibility, but It does make it possible to calculate New Zealand’s contribution to oceanic pollution. Although we are led to believe that our use of “single use plastic supermarket bags” was a large contributor to global oceanic pollution, the facts do not bear this out. New Zealand is a first world country and does a very good job of ensuring the vast majority of our domestic waste ends up in landfills. And, of the small amount of litter that gets into our environment, “single use plastic bags" made up just 1%. Interestingly, 40% of our environmental litter is fast food wrappers. It is not absurd to infer that most plastic bags that made it into our environment came from fast food outlets. Which is not a particularly convincing reason to ban supermarket bags.

"Plastic bags kill marine animals"

If you Google search pictures of The Great Pacific Garbage Patch you will find a striking absence of plastic bags. What you will find are a lot of bottles, and bottle caps. All the studies we have read regarding deaths of marine animals by ingestion, blame hard plastics. Plastic degradation is slower in the ocean due to lower temperatures, but relative to thicker plastic, thin walled plastic bags degrade much more quickly. HDPE has a specific gravity is around 0.95, so it floats on or near the surface where it is exposed to sunlight (see above).

Plastic bags are not known to kill marine animals by entanglement. Here is a quote attributed to David Santillo, a senior biologist with Greenpeace, to The Times of London, "It's very unlikely that many animals are killed by plastic bags. The evidence shows just the opposite. We are not going to solve the problem of waste by focusing on plastic bags. With larger mammals it's fishing gear that's the big problem. On a global basis plastic bags aren't an issue."

There is documented evidence that pieces of soft plastic have been ingested by sea turtles. Their known preference is for rubber balloons and clear/translucent plastics such as cling wrap. Studies of our coastline have determined that the known death rate of sea turtles in New Zealand by ingestion of plastic, is two animals per year. However, the information available does not, unfortunately, specify whether these deaths are due to hard or soft plastic. However, comprehensive international studies show that the majority of turtle deaths caused by plastic ingestion are due to hard plastic. The same is true for sea birds.

If even one sea turtle was killed by ingesting a plastic bag it would be tragic. However, the threat of extinction seems much more likely from other causes. The fishing industry kills hundreds of thousands of turtles annually in gill nets and on long lines. People still hunt them for their meat, eggs and shell (for jewelry). Human population growth is encroaching on their breeding grounds, and global sea level rise is eroding their nesting beaches. (Interestingly, unlike most vertebrates, sea turtles do not have sex chromosomes. The sex of their young is determined by the temperature of the sand in which they lay their eggs. A few degrees temperature rise could mean no males are born to continue the species. So a pressing issue in their preservation is control of Global Warming).

"Single use plastic bags were still a massive environmental problem. We used a billion a year"

Recent landfill statistics give us a very accurate picture of what we are consuming by measuring what we are throwing away. So what percentage of landfill is taken up with plastic bags? Plastic waste account for 12.1% of landfill. Roughly half of this (6%) is soft plastic. "Single use plastic bags", however, were just a small fraction of this total. There is an often quoted figure of one billion bags used by Kiwis every year. This may be a little on the high side, but if we use this figure, we can determine the percentage of landfill taken up with single use plastic bags. The average supermarket bag weighs around 5.5 grams (we will call it 6 grams). 1,000,000,000 x 6 grams = 6,000,000,000 grams = 6,000,000 kg = 6,000 tons. Six thousand tons of plastic sounds like a huge quantity but, to our shame, we currently send to landfill around 3 million tons of waste annually so, as a percentage, single use plastic bags made up approximately 0.2% of this total. Less than one quarter of one percent.

"When you put plastic in a land fill it takes a thousand years to break down"

Below ground, deprived of oxygen, HDPE is inert. Similarly, if you send concrete to the landfill, it will remain there, inert. It is strange that a different standard is placed on these two substances. Both have been extracted from the ground, chemically modified and returned to the ground. The main difference is that the lump of concrete will still be a lump of concrete in a billion years. (The plastic bag and its contents may quite possibly have turned back into crude oil).

In truth, if you have to put something in a landfill, you want it to remain there, inert and unchanging. Burying things is not a new practice for humans. If you dig down in the centre of London, you will find evidence of Roman habitation 40 feet below ground. Everything above that was deposited by humans. The argument that HDPE is bad because it is a man-made substance must also be applied to concrete; used by the Romans in ancient London (though invented much earlier than that *). As far as we are aware, there is no environmental group advocating a ban on dumping of concrete in landfills.

"Plastics are a petroleum product so they contribute to Global Warming"

When petroleum products are burned, their carbon content is dispersed into the atmosphere as CO2. When crude oil is turned into plastic the carbon is trapped. If the plastic is burned, its carbon content is released into the atmosphere, but if it is buried, the carbon remains trapped.

Incidentally, if you have ever got close to a jar of crude oil you will know that it is pretty disgusting stuff, for something made by nature. The hydrogen sulfide it gives off, which smells like rotten eggs, can actually kill you. It’s lucky that most of it is buried deep underground. If it was possible to turn all of it into inert HDPE and re-bury it underground the world would, arguably, be a better place.

"I don't care what arguments you put forward, plastic bags are just evil"

Single use plastic supermarket bags” are a tiny subset of all the plastic we use. So, why do we all share a bias against them. We all like to believe that we reason with our frontal lobes, but every decision must pass by our amygdala, the part of our brain that registers fear and disgust. Through many years of subtle indoctrination, “single use plastic bags” have become somehow the embodiment of the disgusting way we treat our planet. When you think about plastic bags you may well think of stinking landfills, or dying sea turtles. But “single use plastic bags" haven’t just fallen into this role. Decades of visual imagery has seared into our brains an association with death and decay and profligate waste. Even the term "single use" is a misnomer, because almost all are used at least twice. But whenever they are discussed in the media, they are never thoughtfully re-purposed, they are "discarded". Next time you see a news article about oceanic pollution, no matter what kind, it will almost certainly be accompanied by a picture of a “single use plastic bag”.

We could quite easily have chosen “single use plastic drink bottles” instead. What is the difference between them? One answer could be that “single use plastic bags” have no strong pro-lobby group. “Single use plastic drink bottles”, as a sub-group, is far more detrimental to the planet than “single use plastic bags”. Their wall thickness is around 50 times that of HDPE film which means they remain intact in the environment far longer. They can be found in their millions in the Great Pacific Garbage Patch and on the shores of Midway Island at its centre, and their bottle caps in the stomach contents of the resident dead albatross chicks. So, why is it these more worthy candidates haven’t come to symbolise our profligate Western lifestyles. One reason is that they have a strong pro-lobby in drinks manufacturers, who constantly bombard us with advertising images associating drinking from them as a joyful, beautiful, life-affirming act. Just as with “single use plastic bags”, its all in the marketing. If you think about it, in the developed world at least, “single use plastic bottles” are completely unnecessary. Everyone in New Zealand has ready access to clean drinking water. Would banning “single use plastic bottles put such a crimp on our decadent western lifestyles? If it was a choice of banning one or the other, perhaps we should keep the one that actually performs a useful function. Of course, it is not as simple as making a choice between banning one thing or another. Every choice we make affects our planet.

If you have read this far down the page, you are obviously interested in saving the Planet, but you may be more confused than ever.  So what can you do to help?  Here are 4 simple things you could start with:

Stop buying stuff you don't need. (Clothes, as an example - textiles make up around 4% of landfill waste).

Stop buying bottled water, or anything else that comes in a single use plastic bottle. Just Google a picture of Midway Island and you will see just how long they can last in the environment. If you want to get really depressed, look at the pictures of the decaying bodies of albatross chicks and see how many bottle caps you can count.

Most importantly, buy a green waste bin and use it for everything compostable that leaves your home.

If you don't live in an area where your council offers a green waste collection service, find a private one. Not only will you be reducing your harmful greenhouse gas emissions (around 4 tons per household per year), you will be helping to more than double the useful life of you local landfill. By the way, the reason it is not possible to build houses on a landfill immediately after decommissioning it, is less about what it seeping out of the bottom of it than what is seeping out of the top. Methane continues to gas-off for decades.

Agitate with your local council to use recycled plastic products instead of treated timber so that the supermarkets can restart their soft plastics collections.

Then …

Spread the word to your friends and family. Tell them what you are doing and why, and remind them that you are doing it for their children and grandchildren.

"But I would like to do more"

Great. Start a community group. Push for your local council to supply optional green waste bins to all households. If you want to get militant, insist that these green waste bins be compulsory for every household. Once you have achieved that, think nationally. Start writing letters to your local MP. Get the rest of your group to do the same. Together, with small steps, we can make a huge difference.  Here is an example:

Dear Eugenie

I have learned that in New Zealand we are presently sending massive quantities of biodegradable material to landfills in the form of domestic green waste and kitchen scraps. Magnified by its conversion to methane, this is a significant contributor to Global Warming.

I would like you to consider a law making it compulsory for all Councils to supply separate green waste bins to every domestic dwelling in New Zealand.

Yours sincerely

"Why is there so much misinformation on the internet? How can I get the truth?"

Arm yourself with a little knowledge. Saving the planet is not rocket science, but it is science.

Google searches rank by popularity, not plausibility. Think about the wording of your search choices. If you type in “911 was a conspiracy”, then conspiracy is what you will get. Check every source. Verify facts. On matters of science, look for well known organisations, who publish peer reviewed studies. And please think before you “like” or “share”. The uncritical repetition of improbable facts makes us all more ignorant. The recent plastic bag debate is a good example.

Ask, does this group have an agenda? For example, the information you are currently reading comes from a site that sells plastic bags. Why should you trust what is said here?** Companies wanting to sell you stuff, and even some environmentalists pushing a particular agenda, can bend the truth. (see the TED talk at the very bottom of this page)

And it is possible to lie by omission. Retailers who tout cornstarch or paper waste bags as an alternative to HDPE, tell you they are better for the environment. However, they neglect to mention that, unless you compost these bags yourself, they will almost certainly end up in a landfill, where they will produce methane, which is incredibly bad for the environment.

** An explanation as to why you might be able to trust what is being said here (though we strongly recommend you conduct your own independent research) is that we sell dog waste bags, so until the general public can be convinced to pick up dog poo with their bare hands, dog poo bags will be exempt from any proposed ban. However, now that all “single use plastic supermarket bags” are banned, we gain financially, because a lot of people previously reused their supermarket bags to pick up poo. So why did we defend supermarket bags? Because fixing problems requires us to base our reasoning on facts. Banning these bags was illogical and has created more problems than it has solved***.

And the conversation sucked valuable oxygen away from what we should be concentrating on.

We need to fix our attention squarely on global temperature rise. This is the thing melting the polar ice caps, that will flood heavily populated low lying areas of the planet, causing refugee crises, famine and war; the thing that will cause the extermination of species by the hundreds of thousands. A global temperature rise of just a few degrees.

If we can convince every consumer of the planet's resources to start doing these small, unglamorous things, together we can achieve something huge. But if we expect New Zealand to become carbon neutral, every New Zealand household must be working towards that same goal.

*** One of the problems with changing the equilibrium of any environment, is the law of unintended consequences.  As an example, it was once considered a brilliant idea to introduce the Australian Possum to New Zealand so that it could employ people in the fur trade. The result has been the devastation of our native flora and fauna.

Consequences can be equally catastrophic when you ban something. A scientific study undertaken in San Francisco after their ban on single use plastic bags, postulated that an average annual increase in deaths by bacterial infection of 5.5 people per year was attributable to the increased use of reusable grocery bags. (Another study found out why they might be a problem - ninety percent of them never get washed.) This hypothesis, if proven correct, would be a tragic illustration of this.

But even the more mundane consequences of banning plastic bag are not talked about. People must have an alternative, and every alternative has an environmental cost. A non-woven multi-use polypropylene bag weighs 80 grams, an HDPE bag weighs 6 grams. So, if you can get 10 trips from an HDPE bag, you need to get well over 100 trips from a polyprop bag. So if you don't get more than 2 years out of your polyprop bag (assuming approximately one supermarket trip a week), then from an environmental standpoint, you are no better off than if you had been using HDPE bags. But in the meantime, people will still be buying bags for bin liners, dog poo pick up, and every other task for which they repurposed their HDPE bags. So the net result could well be more plastic, not less.

And if you have ever thrown away a multi-use bag because you somehow ended up with too many, rest assured that you are almost certainly not alone. And if it is just now dawning on you that it was made of jute, and you put it in your rubbish bin, so it went to the landfill, where it decomposed anaerobically, which produced methane with a global warming potential of 30 jute bags, then please congratulate yourself, you have obviously been paying attention.

Concrete and other problems

We have included a couple of interesting facts about concrete to help illustrate the point that in environmentalism things aren't always quite as straightforward as they might be portrayed to be. Plus, it might make you think twice about ripping up and re-concreting your driveway just because it is looking a bit shabby.

Concrete was first used by humans around 6,500 years ago. Modern production of cement creates a lot of carbon dioxide, up to 1 ton of CO2 for every 1 ton of cement produced. Cement production accounts for approximately 7% of world-wide greenhouse gas emissions.

Hydroelectric power generation is thought of as green energy. However, hydro schemes require dams, which are made of concrete. The Clyde Dam contains 1,000,000 tons of concrete. If you calculate the embodied energy of the cement required to build the dam, it comes to around 6 hundred million megajoules. The power output of the Clyde power station is 7.5 million megajoules per year. So it will take 79 years for this power station to cancel out the embodied energy required to make it. The Clyde started producing power in 1993, so it should have that debt paid off by 2072. If it is still running by then, it will truly be producing green energy.

There are ways to make concrete more environmentally friendly. One way is to add fly ash. The addition of fly ash can reduce the CO2 producing ingredients of cement by up to 90%. Ironically, the main source of fly ash is coal fired power stations.

PAPER, CORNSTARCH, JUTE AND COTTON Bags - some inconvenient truths

Paper bags are often marketed as being greener than plastic bags. Paper, it turns out, is a dirty business. We recommend that you do your own research. Here are a few categories you could select in order to make up your own mind. Just Google paper production and:

deforestation, air pollution, water pollution, water consumption, landfill methane, carbon monoxide, ammonia, nitrogen oxide, mercury, nitrates, benzene, volatile organic compounds, bleaching.

Much of the paper associated with food wrapping becomes contaminated to the point where you would not put it in your recycle bin. But even uncontaminated paper cannot be infinitely recycled (a maximum of 4 times until the fibres become too short to bind to each other). So, eventually , unless it is burnt, all paper will end up in a landfill where it will, as we all know, produce methane.

And paper with printing on it, has additional problems. Google: recycled paper and de-inking.

There are five main problems associated with the use of cornstarch bags. Firstly, their production takes valuable farm land away from food cultivation. Secondly, they don't break down as quickly as promised. This can be especially troublesome when they are labelled “Flushable”. Thirdly they contaminate plastic recycling. Being visually indistinguishable from petroleum based plastics, they are unable to be sorted from the waste stream. This a serious problem for those involved in recycling standard soft plastics. Fourthly, if bags are labeled biodegradable, people tend to be less careful in their disposal.  Since cornstarch only degrades readily in industrial composting where the temperature are much higher than you find in the general environment, when disposed of carelessly, these bags can last as long in the environment as HDPE bags.  But the fifth and major problem they have is that if they end up in a landfill, which the vast majority of them will, they create methane. Plus any organic matter they contain will then be exposed to water and will also turn into methane.

Jute is hailed by many environmentalists as a saviour of the planet. More than 95 percent of the World's jute production occurs on the Ganges Delta, which sprawls across India's West Bengal and a large part of Bangladesh. If you know anything about Bangladesh, you will be aware that it is blessed with inordinate quantities of water (often way too much of it). Everything we grow has a water requirement. Potatoes, for example, have a water requirement of 287 M3/ton (cubic metres per metric ton). While not as thirsty as cotton, jute requires a large amount of water for its production (2,605 M3/ton). That is slightly more than the quantity of water in an olympic size swimming pool.  Approximately ten percent of this figure is grey water component, or water that is required to process to final product and is contaminated in this manufacturing process. With water becoming a scarce commodity in many parts of the world, it does not seem that there are many places where an up-scaling of jute production would be feasible. In case you are wondering, HDPE bags do not use any appreciable water in their manufacture. If a jute bag weighs 100gm then it took approximately 260 litres of water to produce the material it is made from (this does not take into account any further processing or dying that may have occurred).

If you want to dispose of your worn out jute bag responsibly, please do not put it in your household rubbish. The safest thing you could do is burn it. That way, hopefully, all you will be releasing into the atmosphere is CO2 (provided it has no inorganic printing on it).

A comprehensive study commissioned in 2006 by the UK Government determined that a cotton bag has the same Global Warming Potential as 327 "single use" plastic bags, so would need to be reused a staggering 327 times to equal the environmental impact of using a new  "single use" HDPE bag for each shopping trip.  This number is so large, it may not make sense to you.  So let us put it another way.  Say you use your cotton bag for your once-a-week supermarket shop.  In order for it to have a less  detrimental impact on the Planet than using a brand new "single use" plastic bag every time you shop, you will have to use it for 6 years and three months.  Let's say you decided you could squeeze two uses out of your "single use" plastic bag before you turn it into a bin liner.  Then, in order to match that, your cotton bag would have to last 12 years and 4 months.  Three uses, 18 years 6 months.  Four uses, 24 years 8 months etc.  Provided you burn it once it has worn out.

Everything we do has a cost.

Carbon sequestration

You will be hearing a lot more about this in the near future, because our future will depend upon it.  Some “eco-friendly” sellers already boast that their green products sequester carbon. Just as an example, some who sell jute bags and other jute products, claim that the jute takes carbon out of the atmosphere. While this is true when the plant is growing, there is just one problem with this argument. When any biodegradable material is disposed of, the carbon is released again, sometimes as CO2 and sometimes as Methane. If you are trying to reduce total atmospheric carbon, you need to make sure that once sequestered, it cannot escape back into the atmosphere. This is, in practice, impossible with an organic product.  Unless you bury it underground sealed in a container that is impervious to water (like an HDPE bag, for example).


Environmental Exaggeration