Why does wool get such high embodied energy ratings?

4 08 2009

The more I learn about organic farming the more impressed I become with the dynamics of it all.   As Fritz Capra has said, we live in an interconnected and self-organizing universe of changing patterns and flowing energy. Everything has an intrinsic pattern which in turn is part of a greater pattern – and all of it is in flux.  That sure makes it hard to do an LCA, and it makes for very wobbly footing if somebody takes a stand and defends it against all comers.

For example, I have been under the impression (based on some published LCA’s) that the production of wool is very resource inefficient, largely based on the enormous need for water: it’s generally assumed that 170,000 litres of water is needed to produce 1 KG of wool    (versus anywhere from 2000 to 5300 to produce the same amount of cotton).  That’s because the livestock graze on land and depend on rainwater for their water – and some LCA’s base the water use on the lifetime of the sheep (reminding me to check the research parameters when referring to published LCA’s).

In addition, industrial agricultural livestock production often results in overgrazing.  As we now see in the western United States, overgrazing in extreme cases causes the land to transform from its natural state of fertility to that of a desert. At the very least, it severely limits plant reproduction, which in turn limits the soil’s ability to absorb water and maintain its original nutrient balance, making overgrazing difficult to recover from. And then there’s methane: livestock are often vilified for producing more greenhouse gases than automobiles.

The exciting thing is that what is known as “holistic management” of the soil makes it possible to use animals to improve, rather than degrade, land.  What’s consistently ignored in the research  is the failure to distinguish between animals raised in confined feedlots and animals grazing on rangeland  in a holistic system.  Research on holistic land management is, in fact, showing that large grazing animals are a vital and necessary part of the solution to climate change and carbon sequestration. Read about holistic land management on the Holistic Managmeent Institute (HMI) website.

The reason holistic practices work, according to HMI, is that grazing animals and grassland co-evolved.  According to the HMI website, hooves and manure accomplish what mechanical tilling and petrochemical fertilizers cannot: healthy, diverse grassland with abundant root systems and improved soil structures that makes highly effective use of existing rainfall.  Domestic animals can be managed in ways that mimic nature, called “planned grazing”:  rather than allowing animals to linger and eat from the same land repeatedly,  animals are concentrated and moved according to a plan which allows the land long periods of rest and recovery.   This planned grazing allows the animals to till packed soil with their hooves, distribute fertilizer and seed in their manure and urine, and move from one area to another before they can overgraze any one spot. In fact, the animals help maintain the soil, rather than destroying it, and increase the amount of organic matter in the soil, making it function as a highly effective carbon bank. Properly managed, grazing animals can help us control global climate change:  soil carbon increased 1% within a 12 month period  in a planned grazing project (a significant increase).

This carbon is essential to not only feeding soil life and pasture productivity, but it also affects water infiltration rates. On one trial site where planned grazing was implemented, within two years, the  soil water infiltration rate increased eightfold in comparison to the conventional grazing treatment.

In addition, holistic management of grazing animals eliminates the need for the standard practice of burning crop and forage residues.  That burning currently sends carbon directly into the atmosphere.  If we convert just 4 million acres of land that’s operating under the traditional, conventional agriculture model to holistically managed land – so the residue is not burned – the carbon is captured rather than released.   Look at the difference in erosion in the picture below: compare the severely eroded, conventionally managed riverbank on the left with the Holistically Managed bank on the right.  All the shrubbery and grass means abundant root systems and healthy soil infrastructure underground – both of these sequester CO2.

HOLISTIC mgmtWhat you see on the right is the result of managed animal impact.                     Source: Holistic Management International

According to Christine Jones, Founder, Australian Soil Carbon Accreditation, “The fabulous thing about sequestering carbon in grasslands is that you can keep on doing it forever – you can keep building soil on soil on soil… perennial grasses can outlive their owners; they’re longer-lived than a lot of trees, so the carbon sequestration is more permanent than it is in trees: the carbon’s not going to re-cycle back into the atmosphere if we maintain that soil management… and there’s no limit to how much soil you can build… for example, we would only have to improve the stored carbon percentage by one percent on the 415 million hectares (1,025,487,333 acres) of agricultural soil in Australia and we could sequester all of the planet’s legacy load of carbon. It’s quite a stunning figure.”

 

Data from a demonstration project in Washington State is confirming other worldwide research that grazing could be better for the land than growing certain crops in dryland farming regions – it reverses soil decline (erosion and desertification), restores soil health, and instead of losing carbon through tilling or systems requiring inputs (like wheat farming) planned grazing sequesters carbon; biomass to soak up carbon is increased, and the use of fossil fuel has been reduced by more than 90%.  Wildlife habitat has improved.  The Washington State project even sells carbon credits.

In April of this year, Catholic Relief Service, one of the country’s largest international humanitarian agencies, is launching a worldwide agricultural strategy that adopts a holistic, market oriented approach to help lift millions of people out of poverty.   Read more about this here.

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Cotton is a good way to buy oil.

21 07 2009

Provocative title, isn’t it?  But I didn’t say it, the statement comes from Jim Rogers, one of the world’s most successful investors and co-founder of the Quantum Fund (with George Soros) from which he retired in 1980.  Since then he has been a college professor, world traveler, author, economic commentator and creator of the Rogers International Commodities Index.  And now, Jim Rogers says he’s investing in agriculture.

Jim Rogers is looking at cotton as a commodity (and an investment strategy), based on the fact that almost everything has some dependence on energy prices, based on  the embodied energy of the product.  He bases his decision on the fact that so many textiles today are made from synthetics – which come from oil.  Since the price of oil is going up (and will likely continue to go up) the price of synthetics is also going up.  So textile makers are reverting to natural fibers.  Cotton is the most popular natural fiber in the world, and the cotton – oil connection is both direct (through the use of synthetic fertilizers and pesticides), and indirect  (land formerly used to grow cotton can be shifted to other production to feed ethanol demand).  As Jim Rogers says,  “I hadn’t thought of this cotton-oil connection before, and it’s drawing these connections before others do that makes a great investor.”

If we are going to “reduce our dependence on foreign oil” (as the government likes to put it), shouldn’t we be looking at agriculture?  Dr. Albert Bartlett, Professor Emeritus in Nuclear Physics at Colorado University, Boulder, has said that the definition of “modern agriculture is the use of land to convert petroleum into food”.

I checked the web – and agriculture is really an energy hog.  According to the website Food and Water Watch:

  • 20% of the fossil fuel used in the US goes toward food production.
  • This inefficient system spends 10,551 quadrillion joules of energy each year – about the same as used by all of France.
  • The US EPA reported that US agriculture is responsible for the same amount of CO2 emissions per year as 141,000,000 cars.  Emissions DOUBLE when electricity usage is included.

Kenneth Watt, on the very first Earth Day in 1970, said that our very existence is dependent on the massive import of energy into industrial agriculture from petroleum, natural gas and coal – and this massive energy use creates a “fossil fuel subsidy”:  that means the use of petroleum has enabled fewer farmers to produce much more food on less land, so the population can grow.

Petroleum-based agriculture has reduced the proportion of the US population engaged in agriculture from about 50% about 75 years ago to less than 2% today.  In other words, the average American farmer feeds lots of people, as well as having enough left over to ship abroad. Petroleum also lets Floridians eat salmon from Alaska, and Alaskans enjoy orange juice from Florida. Between 1950 and 1970, the last 11 million horses were taken out of American agriculture and replaced by tractors powered by crude oil. Since it takes very roughly four times the acreage to support one horse as a person, this means we have been able to add 44 million people to the American population [in those twenty years] for that one cause alone, because of a fossil fuel subsidy.

According to Kenneth Watt, “mankind is embarked on an absolutely immense gamble. We are letting the population build up and up and up, by increasing the carrying capacity of the Earth for people, using a crude-oil energy subsidy, on the assumption that there’s no inherent danger in this because when the need arises we’ll be able to get ultimate sources of energy.”

But what happens if we don’t have alternate sources of energy,  when the oil crunch appears?  As oil production declines, prices will rise – especially commodities – and most especially food.

So how can organic agriculture help us with this dire picture.  You’ll be surprised!  Check in next week.





Why is recycled polyester considered a sustainable textile?

14 07 2009

 

plastic_bottles

Synthetic fibers are the most popular fibers in the world – it’s estimated that synthetics account for about 65% of world production versus 35% for natural fibers.[1] Most synthetic fibers (approximately 70%) are made from polyester, and the polyester most often used in textiles is polyethylene terephthalate (PET).   Used in a fabric, it’s most often referred to as “polyester” or “poly”.

The majority of the world’s PET production – about 60% – is used to make fibers for textiles; about 30% is used to make bottles.   It’s estimated that it takes about 104 million barrels of oil for PET production each year – that’s 70 million barrels just to produce the virgin polyester used in fabrics.[2] That means most polyester – 70 million barrels worth –  is manufactured specifically to be made into fibers, NOT bottles, as many people think.  Of the 30% of PET which is used to make bottles, only a tiny fraction is recycled into fibers.  But the idea of using recycled bottles – “diverting waste from landfills” – and turning it into fibers has caught the public’s imagination.

The reason recycled polyester (often written rPET) is considered a green option in textiles today is twofold, and the argument goes like this:

  1. energy needed to make the rPET is less than what was needed to make the virgin polyester in the first place, so we save energy.
  2. And  we’re keeping bottles and other plastics out of the landfills.

Let’s look at these arguments.

1) The energy needed to make the rPET is less than what is needed to make the virgin polyester, so we save energy:

 

It is true that recycling polyester uses less energy that what’s needed to produce virgin polyester.  Various studies all agree that it takes  from 33%  to 53% less energy[3].  If we use the higher estimate, 53%,  and take 53% of the total amount of energy needed to make virgin polyester (125 MJ per KG of ton fiber)[4], the amount of energy needed to produce recycled polyester in relation to other fibers is:

Embodied Energy used in production of various fibers:

energy use in MJ per KG of fiber:

hemp, organic

2

flax

10

hemp, conventional

12

cotton, organic, India

12

cotton, organic, USA

14

cotton,conventional

55

wool

63

rPET

66

Viscose

100

Polypropylene

115

Polyester

125

acrylic

175

Nylon

250

rPET is also cited as producing far fewer emissions to the air than does the production of  virgin polyester: again estimates vary, but Libolon’s website introducing its new RePET yarn put the estimate at 54.6% fewer CO2 emissions.  Apply that percentage to the data from the Stockholm Environment Institute[5], cited above:

KG of CO2 emissions per ton of spun fiber:

crop cultivation

fiber production

TOTAL

polyester USA

0

9.52

9.52

cotton, conventional, USA

4.2

1.7

5.89

rPET

5.19

hemp, conventional

1.9

2.15

4.1

cotton, organic, India

2

1.8

3.75

cotton, organic, USA

0.9

1.45

2.35

Despite the savings of both energy and emissions from the recycling of PET, the fact is that it is still more energy intensive to recycle PET into a  fiber than to use organically produced natural fibers – sometimes quite a bit more energy.

2) We’re diverting bottles and other plastics from the landfills.

 

That’s undeniably true,  because if you use bottles then they are diverted!

But the game gets a bit more complicated here because rPET is divided into “post consumer” PET and “post industrial” rPET:  post consumer means it comes from bottles; post industrial might be the unused packaging in a manufacturing plant, or other byproducts of manufacturing.  The “greenest” option has been touted to be the post consumer PET, and that has driven up demand for used bottles. Indeed, the demand for used bottles, from which recycled polyester fibre is made, is now outstripping supply in some areas and certain cynical suppliers are now buying NEW, unused bottles directly from bottle producing companies to make polyester textile fiber that can be called recycled.[6]

Using true post consumer waste means the bottles have to be cleaned (labels must be removed because labels often contain PVC) and sorted.  That’s almost always done in a low labor rate country since only human labor can be used.   Add to that the fact that the rate of bottle recycling is rather low – in the United States less than 6% of all waste plastic gets recycled [7].  The low recycling rate doesn’t mean we shouldn’t continue to try, but in the United States where it’s relatively easy to recycle a bottle and the population is relatively well educated in the intricacies of the various resin codes, doesn’t it make you wonder how successful we might be with recycling efforts in other parts of the world?

pet-recycling-graph-2 SOURCE: Container Recycling Institute

There are two types of recycling:  mechanical and chemical:

    • Mechanical recycling is accomplished by melting the plastic and re-extruding it to make yarns.  However, this can only be done  few times before the molecular structure breaks down and makes the yarn suitable only for the landfill[8] where it may never biodegrade, may biodegrade very slowly, or may add harmful materials to the environment as it breaks down (such as antimony).  William McDonough calls this  “downcycling”.
    • Chemical recycling means breaking the polymer into its molecular parts and reforming the molecule into a yarn of equal strength and beauty as the original.  The technology to separate out the different chemical building blocks (called depolymerization) so they can be reassembled (repolymerization) is very costly and almost nonexistent.

Most recycling is done mechanically (or as noted above, by actual people). Chemical recycling does create a new plastic which is of the same quality as the original,  but the process is very expensive and is almost never done, although Teijin has a new program which recycles PET fibers into new PET fibers.

The real problem with making recycled PET a staple of the fiber industry is this:  recycling, as most people think of it, is a myth.  Most people believe that plastics can be infinitely recycled  – creating new products of a value to equal the old bottles or other plastics which they dutifully put into recycling containers to be collected. The cold hard fact is that there is no such thing as recycling plastic, because it is not a closed loop.  None of the soda and milk bottles which are collected from your curbside are used to make new soda or milk bottles, because each time the plastic is heated it degenerates, so the subsequent iteration of the polymer is degraded and can’t meet food quality standards for soda and milk bottles.  The plastic must be used to make lower quality products.  The cycle goes something like this:

  • virgin PET can be made into soda or milk bottles,
  • which are collected and recycled into resins
    • which are appropriate to make into toys, carpet, filler for pillows, CD cases, plastic lumber products,  fibers or a million other products. But not new soda or milk bottles.
  • These second generation plastics can then be recycled a second time into park benches, carpet, speed bumps or other products with very low value.
  • The cycle is completed when the plastic is no longer stable enough to be used for any product, so it is sent to the landfill
    • where it is incinerated (sometimes for energy generation, which a good LCA will offset)  –
    • or where it will hold space for many years or maybe become part of the Great Pacific Garbage Patch![9]

And there is another consideration in recycling PET:  antimony, which is present in 80 – 85% of all virgin PET[10], is converted to antimony trioxide at high temperatures – such as are necessary during recycling, releasing this carcinogen from the polymer and making it available for intake into living systems.

Using recycled PET for fibers also creates some problems specific to the textile industry:

  • The base color of the recycled polyester chips vary from white to creamy yellow, making color consistency difficult to achieve, particularly for the pale shades.  Some dyers find it hard to get a white, so they’re using chlorine-based bleaches to whiten the base.
  • Inconsistency of dye uptake makes it difficult to get good batch-to-batch color consistency and this can lead to high levels of re-dyeing, another very high energy process.  Re-dyeing contributes to high levels of water, energy and chemical use.
  • Unsubstantiated reports claim that some recycled yarns take almost 30% more dye to achieve the same depth of shade as equivalent virgin polyesters.[11]
  • Another consideration is the introduction of PVC into the polymer from bottle labels and wrappers.
  • Many rPET fibers are used in forgiving constructions such as polar fleece, where the construction of the fabric hides slight yarn variations.  For fabrics such as satins, there are concerns over streaks and stripes.

Once the fibers are woven into fabrics, most fabrics are rendered non-recyclable  because:

  • the fabrics almost always have a chemical backing, lamination or other finish,
  • or they are blends of different synthetics (polyester and nylon, for example).

Either of these renders the fabric unsuitable for the mechanical method of recycling, which cannot separate out the various chemicals in order to produce the recycled yarn; the chemical method could  –   if we had the money and factories to do it.

One of the biggest obstacles to achieving McDonough’s Cradle-to-Cradle vision lies outside the designers’ ordinary scope of interest – in the recycling system itself. Although bottles, tins and newspapers are now routinely recycled, furniture and carpets still usually end up in landfill or incinerators, even if they have been designed to be  recycled [12] because project managers don’t take the time to separate out the various components of a demolition job, nor is collection of these components an easy thing to access.

Currently, the vision that most marketers has led us to believe, that of a closed loop, or cycle, in which the yarns never lose their value and recycle indefinitely is simply that – just a vision.  Few manufacturers, such as Designtex (with their line of EL fabrics designed to be used without backings) and Victor Innovatex (who has pioneered EcoIntelligent™ polyester made without antimony),  have taken the time, effort and money needed to accelerate the adoption of sustainable practices in the industry so we can one day have synthetic fabrics that are not only recycled, but recyclable.


[1]“New Approach of Synthetic Fibers Industry”, Textile Exchange,  http://www.teonline.com/articles/2009/01/new-approach-of-synthetic-fibe.html

[2] Polyester, Absolute Astronomy.com: http://www.absoluteastronomy.com/topics/Polyester and Pacific Institute, Energy Implications of Bottled Water, Gleick and Cooley, Feb 2009, http://www.pacinst.org/reports/bottled_water/index.htm)

[3] Website for Libolon’s RePET yarns:  http://www.libolon.com/eco.php

[4] Data compiled from:  “LCA: New Zealand Merino Wool Total Energy Use”, Barber and Pellow,                                                                       http://www.tech.plym.ac.uk/sme/mats324/mats324A9%20NFETE.htm and  “Ecological Footprint and Water

Analysis of Cotton, Hemp and Polyester”, by Cherrett et al, Stockholm Environment Institute

[5] “Ecological Footprint and Water Analysis of Cotton, Hemp and Polyester”, by Cherrett et al, Stockholm Environment Institute

[6] The Textile Dyer, “Concern over Recycled Polyester”,May 13, 2008,

[7] Watson, Tom, “Where can we put all those plastics?”, The Seattle Times, June 2, 2007

[8] William McDonough and Michael Braungart, “Transforming the Textile Industry”, green@work, May/June 2002.

[9] See http://www.greatgarbagepatch.org/

[10] Chemical Engineering Progress, May 2003

[11] “Reduce, re-use,re-dye?”,  Phil Patterson, Ecotextile News, August/September 2008

[12] “Taking Landfill out of the Loop”, Sarah Scott, Azure, 2006





Elephants Among Us

29 06 2009

 

Although most of the current focus on lightening our carbon footprint revolves around transportation and heating issues, the modest little fabric all around you turns out to be from an industry with a gigantic carbon footprint. The textile industry, according to the U.S. Energy Information Administration, is the 5th largest contributor to CO2 emissions in the United States, after primary metals, nonmetallic mineral products, petroleum and chemicals.[1]

The textile industry is huge, and it is a huge producer of greenhouse gasses.  Today’s textile industry is one of the largest sources of greenhouse gasses (GHG’s) on Earth, due to its huge size.[2] In 2008,  annual global textile production was estimated at  60 billion kilograms (KG) of fabric.  The estimated energy and water needed to produce that amount of fabric boggles the mind:

  • 1,074 billion kWh of electricity  or 132 million metric tons of coal and
  • between 6 – 9 trillion liters of water[3]

Fabrics are the elephant in the room.  They’re all around us  but no one is thinking about them.  We simply overlook fabrics, maybe because they are almost always used as a component in a final product that seems rather innocuous:  sheets, blankets, sofas, curtains, and of course clothing.  Textiles, including clothing,  accounted for about one ton of the 19.8 tons of total CO2 emissions produced by each person in the U.S. in 2006. [4] By contrast, a person in Haiti produced a total of only 0.21 tons of total carbon emissions in 2006.[5]

Your textile choices do make a difference, so it’s vitally important to look beyond thread counts, color and abrasion results.

How do you evaluate the carbon footprint in any fabric?  Look at the “embodied energy’ in the fabric – that is, all of the energy used at each step of the process needed to create that fabric.  To estimate the embodied energy in any fabric it’s necessary to add the energy required in two separate fabric production steps:

(1)  Find out what the fabric is made from, because the type of fiber tells you a lot about the energy needed to make the fibers used in the yarn.  The carbon footprint of various fibers varies a lot, so start with the energy required to produce the fiber.

(2) Next, add the energy used to weave those yarns into fabric.  Once any material becomes a “yarn” or “filament”, the amount of energy and conversion process to weave that yarn into a textile is pretty consistent, whether the yarn is wool, cotton, nylon or polyester.[6]

Let’s look at #1 first: the energy needed to make the fibers and create the yarn. For ease of comparison we’ll divide the fiber types into “natural” (from plants, animals and less commonly, minerals) and “synthetic” (man made).

For natural fibers you must look at field preparation, planting and field operations (mechanized irrigation, weed control, pest control and fertilizers (manure vs. synthetic chemicals)), harvesting and yields.  Synthetic fertilizer use is a major component of the high cost of conventional agriculture:  making just one ton of nitrogen fertilizer emits nearly 7 tons of CO2 equivalent greenhouse gases.

For synthetics, a crucial fact is that the fibers are made from fossil fuels.   Very high amounts of energy are used in extracting the oil from the ground as well as in the production of the polymers.

A study done by the Stockholm Environment Institute on behalf of the BioRegional Development Group  concludes that the energy used (and therefore the CO2 emitted) to create 1 ton of spun fiber is much higher for synthetics than for hemp or cotton:

KG of CO2 emissions per ton of spun fiber:

crop cultivation

fiber production

TOTAL

polyester USA

0.00

9.52

9.52

cotton, conventional, USA

4.20

1.70

5.89

hemp, conventional

1.90

2.15

4.10

cotton, organic, India

2.00

1.80

3.75

cotton, organic, USA

0.90

1.45

2.35

The table above only gives results for polyester; other synthetics have more of an impact:  acrylic is 30% more energy intensive in its production than polyester [7] and nylon is even higher than that.

Not only is the quantity of GHG emissions of concern regarding synthetics, so too are the kinds of gasses produced during production of synthetic fibers.  Nylon, for example, creates emissions of N2O, which is 300 times more damaging than CO2 [8] and which, because of its long life (120 years) can reach the upper atmosphere and deplete the layer of stratospheric ozone, which is an important filter of UV radiation.  In fact, during the 1990s, N2O emissions from a single nylon plant in the UK were thought to have a global warming impact equivalent to more than 3% of the UK’s entire CO2 emissions.[9] A study done for the New Zealand Merino Wool Association shows how much less total energy is required for the production of natural fibers than synthetics:

Embodied Energy used in production of various fibers:

energy use in MJ per KG of fiber:
flax fibre (MAT)

10

cotton

55

wool

63

Viscose

100

Polypropylene

115

Polyester

125

acrylic

175

Nylon

250

SOURCE:  “LCA: New Zealand Merino Wool Total Energy Use”, Barber and Pellow,      http://www.tech.plym.ac.uk/sme/mats324/mats324A9%20NFETE.htm

Natural fibers, in addition to having a smaller carbon footprint in the production of the spun fiber, have many additional  benefits:

  1. being able to be degraded by micro-organisms and composted (improving soil structure); in this way the fixed CO2 in the fiber will be released and the cycle closed.   Synthetics do not decompose: in landfills they release heavy metals and other additives into soil and groundwater.  Recycling requires costly separation, while incineration produces pollutants – in the case of high density polyethylene, 3 tons of CO2 emissions are produced for ever 1 ton of material burnt.[10] Left in the environment, synthetic fibers contribute, for example, to the estimated 640,000 tons of abandoned fishing nets in the world’s oceans.
  2. sequestering carbon.  Sequestering carbon is the process through which CO2 from the atmosphere is absorbed by plants through photosynthesis and stored as carbon in biomass (leaves, stems, branches, roots, etc.) and soils.  Jute, for example, absorbs 2.4 tons of carbon per ton of dry fiber.[11]

Substituting organic fibers for conventionally grown fibers is not just a little better – but lots better in all respects:  uses less energy for production, emits fewer greenhouse gases and supports organic farming (which has myriad environmental, social and health benefits).  A study published by Innovations Agronomiques (2009) found that 43% less GHG are emitted per unit area under organic agriculture than under conventional agriculture.[12] A study done by Dr. David Pimentel of Cornell University found that organic farming systems used just 63% of the energy required by conventional farming systems, largely because of the massive amounts of energy requirements needed to synthesize nitrogen fertilizers. Further it was found in controlled long term trials that organic farming adds between 100-400kg of carbon per hectare to the soil each year, compared to non-organic farming.  When this stored carbon is included in the carbon footprint, it reduces the total GHG even further.[13] The key lies in the handling of organic matter (OM): because soil organic matter is primarily carbon, increases in soil OM levels will be directly correlated with carbon sequestration. While conventional farming typically depletes soil OM, organic farming builds it through the use of composted animal manures and cover crops.

Taking it one step further beyond the energy inputs we’re looking at, which help to mitigate climate change, organic farming helps to ensure other environmental and social goals:

  • eliminates the use of synthetic fertilizers, pesticides and genetically modified organisims (GMOs) which is  an improvement in human health and agrobiodiversity
  • conserves water (making the soil more friable so rainwater is absorbed better – lessening irrigation requirements and erosion)
  • ensures sustained biodiversity
  • and compared to forests, agricultural soils may be a more secure sink for atmospheric carbon, since they are not vulnerable to logging and wildfire.

Organic agriculture is an undervalued and underestimated climate change tool that could be one of the most powerful strategies in the fight against global warming, according to Paul Hepperly, Rodale Institute Research Manager. The Rodale Institute Farming Systems Trial (FST) soil carbon data (which covers 30 years)  provides convincing evidence that improved global terrestrial stewardship–specifically including regenerative organic agricultural practices–can be the most effective currently available strategy for mitigating CO2 emissions.

At the fiber level it is clear that synthetics have a much bigger footprint than does any natural fiber, including wool or conventionally produced cotton.   So in terms of the carbon footprint at the fiber level, any natural fiber beats any synthetic – at this point in time.   Best of all is an organic natural fiber.

 

And next let’s look at #2, the energy needed to weave those yarns into fabric.

There is no dramatic difference in the amount of energy needed to weave fibers into fabric depending on fiber type..[14] The processing is generally the same whether the fiber is nylon, cotton, hemp, wool or polyester:   thermal energy required per meter of cloth is 4,500-5,500 Kcal and electrical energy required per meter of cloth is 0.45-0.55 kwh. [15] This translates into huge quantities of fossil fuels  –  both to create energy directly needed to power the mills, produce heat and steam, and power air conditioners, as well as indirectly to create the many chemicals used in production.  In addition, the textile industry has one of the lowest efficiencies in energy utilization because it is largely antiquated.

 

But there is an additional dimension to consider during processing:  environmental pollution.  Conventional textile processing is highly polluting:

  • Up to 2000 chemicals are used in textile processing, many of them known to be harmful to human (and animal) health.   Some of these chemicals evaporate, some are dissolved in treatment water which is discharged to our environment, and some are residual in the fabric, to be brought into our homes (where, with use, tiny bits abrade and you ingest or otherwise breathe them in).  A whole list of the most commonly used chemicals in fabric production are linked to human health problems that vary from annoying to profound.
  • The application of these chemicals uses copious amounts of water. In fact, the textile industry is the #1 industrial polluter of fresh water on the planet.[16] These wastewaters are discharged (largely untreated) into our groundwater with a high pH and temperature as well as chemical load.

Concerns in the United States continue to mount about the safety of textiles and apparel products used by U.S. consumers.  Philadelphia University has formed a new Institute for Textile and Apparel Product Safety, where they are busy analyzing clothing and textiles for a variety of toxins.  Currently, there are few regulatory standards for clothing and textiles in the United States.  Many European countries,  as well as Japan and Australia, have much stricter restrictions on the use of chemicals in textiles and apparel than does the United States, and these world regulations will certainly impact world production.

There is a bright spot in all of this:  an alternative to conventional textile processing does exist.  The new Global Organic Textile Standard (GOTS) is a  tool for an international common understanding of environmentally friendly production systems and social accountability in the textile sector; it covers the production, processing, manufacturing, packaging, labeling, exportation, importation and distribution of all natural fibers; that means, specifically, for example:  use of certified organic fibers, prohibition of all GMOs and their derivatives; and prohibition of a long list of synthetic chemicals (for example: formaldehyde and aromatic solvents are prohibited; dyestuffs must meet strict requirements (such as threshold limits for heavy metals, no  AZO colorants or aromatic amines) and PVC cannot be used for packaging).

A fabric which is produced to the GOTS standards is more than just the fabric:

It’s a promise to keep our air and water pure and our soils renewed; it’s a fabric which will not cause harm to you or your descendants.  Even though a synthetic fiber cannot be certified to  GOTS, the synthetic mill could adopt the same production standards and apply them.   So for step #2, the weaving of the fiber into a fabric, the best choice is to buy a GOTS certified fabric or to apply as nearly as possible the GOTS parameters.

At this point in time, given the technology we have now, an organic fiber fabric, processed to GOTS standards, is (without a doubt) the safest, most responsible choice possible in terms of both stewardship of the earth, preserving health and limiting toxicity load to humans and animals, and reducing carbon footprint – and emphasizing rudimentary social justice issues such as no child labor.

And that would be the end of our argument, if it were not for this sad fact:  there are no natural fiber fabrics made in the United States which are certified to the Global Organic Textile Standard (GOTS).  The industry has, we feel, been flat footed in applying these new GOTS standards.  With the specter of the collapse of the U.S. auto industry looming large, it seems that the U.S. textile industry would do well to heed what seems to be the global tide of public opinion that better production methods, certified by third parties, are the way to market fabrics in the 21st Century.


[1] Source: Energy Information Administration, Form EIA:848, “2002 Manufacturing Energy Consumption Survey,” Form EIA-810, “Monthly Refinery Report” (for 2002) and Documentatioin for Emissions of Greenhouse Gases in the United States 2003 (May 2005). http://www.eia.doe.gov/emeu/aer/txt/ptb1204.html

[2] Dev, Vivek, “Carbon Footprint of Textiles”, April 3, 2009, http://www.domain-b.com/environment/20090403_carbon_footprint.html

[3] Rupp, Jurg, “Ecology and Economy in Textile Finishing”,  Textile World,  Nov/Dec 2008

[4] Rose, Coral, “CO2 Comes Out of the Closet”,  GreenBiz.com, September 24, 2007

[5] U.S. Energy Information Administration, “International Energy Annual 2006”, posted Dec 8, 2008.

[6] Many discussions of energy used to produce fabrics or final products made from fabrics (such as clothing) take the “use” phase of the article into consideration when evaluating the carbon footprint.  The argument goes that laundering the blouse (or whatever) adds considerably to the final energy tally for natural fibers, while synthetics don’t need as much water to wash nor as many launderings.  We do not take this component into consideration because

  • it applies only to clothing; even sheets aren’t washed as often as clothing while upholstery is seldom cleaned.
  • is biodegradeable detergent used?
  • Is the washing machine used a new low water machine?  Is the water treated by a municipal facility?
  • Synthetics begin to smell if not treated with antimicrobials, raising the energy score.

Indeed, it’s important to evaluate the sponsors of any published studies, because the studies done which evaluate the energy used to manufacture fabrics are often sponsored by organizations which might have an interest in the outcome.  Additionally, the data varies quite a bit so we have adopted the values which seem to be agreed upon by most studies.

[7] Ibid.

[8] “Tesco carbon footprint study confirms organic farming is energy efficient, but excludes key climate benefit of organic farming, soil carbon”, Prism Webcast News, April 30, 2008, http://prismwebcastnews.com/2008/04/30/tesco-carbon-footprint-study-confirms-organic-farming%E2%80%99s-energy-efficiency-but-excludes-key-climate-benefit-of-organic-farming-%E2%80%93-soil-carbon/

[9] Fletcher, Kate, Sustainable Fashion and Textiles,  Earthscan, 2008,  Page 13

[10] “Why Natural Fibers”, FAO, 2009: http://www.naturalfibres2009.org/en/iynf/sustainable.html

[11] Ibid.

[12] Aubert, C. et al.,  (2009) Organic farming and climate change: major conclusions of the Clermont-Ferrand seminar (2008) [Agriculture biologique et changement climatique : principales conclusions du colloque de Clermont-Ferrand (2008)]. Carrefours de l’Innovation Agronomique 4. Online at <http://www.inra.fr/ciag/revue_innovations_agronomiques/volume_4_janvier_2009>

[13] International Trade Centre UNCTAD/WTO and Research Institute of Organic Agriculture (FiBL);    Organic Farming and Climate Change; Geneva: ITC, 2007.

[14] 24th session of the FAO Committee on Commodity Problems IGG on Hard Fibers of the United Nations

[15] “Improving profits with energy-efficiency enhancements”, December 2008,  Journal for Asia on Textile and Apparel,  http://textile.2456.com/eng/epub/n_details.asp?epubiid=4&id=3296

[16] Cooper, Peter, “Clearer Communication,” Ecotextile News, May 2007.





What is the energy profile of the textile industry?

16 06 2009

carbon_footprint

If you’ve been following along you’ll know we haven’t even reached the point where we begin weaving – everything up till now dealt only with producing the raw materials (the fiber) and spinning into yarn!

So, the yarns are at the mill.  And that’s the kicker: we’ve been talking about how much energy it takes to produce the various fibers – and it varies dramatically – but there is no dramatic difference in the amount of energy needed to weave fibers into fabric depending on fiber type.[1] The processing is generally the same whether the fiber is nylon, cotton, hemp, wool or polyester:

  • thermal energy required per meter of cloth is 4,500-5,500 Kcal and
  • electrical energy required per meter of cloth is 0.45-0.55 kwh. [2]

This translates into huge quantities of fossil fuels  –  both to create energy directly needed to power the mills, produce heat and steam, and power air conditioners, as well as indirectly to create the many chemicals used in production.  In addition, the textile industry has one of the lowest efficiencies in energy utilization because it is largely antiquated.

So let’s go with the energy used to produce one KG of fabric (which is 92 MJ per KG as the New Zeland Merino Wool LCA study found).   Keeping  the energy needed for production as a  constant the synthetic fabrics still top the list:

Embodied Energy in production of various fibers + processing:
energy use in MJ per KG of fiber: energy use in MJ per KG of fabric TOTAL energy use in MJ per KG of fabric to produce fiber + weave into cloth
flax 10 92 102
Cotton, convt’l. 55 92 147
wool 63 92 155
Viscose 100 92 192
Polypropylene 115 92 207
Polyester 125 92 217
acrylic 175 92 267
Nylon 250 92 342

 

That means that it takes 3,886 MJ of energy to produce 25 yards of nylon fabric, which is  about enough to cover one average sofa.  That compares to 1,158 MJ if the fiber you used was flax (linen).  To put that into perspective, 1 gallon of gasoline equals 131 MJ of energy; driving a Lamborghini from New York to Washington D.C. uses approximately 2266 MJ of energy.(4)

Textile_total_energy_input

In addition to the energy requirements for textile production,  there is an additional dimension to consider during processing:  environmental pollution.  Conventional textile processing is highly polluting:

  • Up to 2000 chemicals are used in textile processing, many of them known to be harmful to human (and animal) health.   Some of these chemicals evaporate, some are dissolved in treatment water which is discharged to our environment, and some are residual in the fabric, to be brought into our homes (where, with use, tiny bits abrade and you ingest or otherwise breathe them in).  A whole list of the most commonly used chemicals in fabric production are linked to human health problems that vary from annoying to profound.  And new research is linking many diseases and disorders to exposure to chemicals.  Through the new science of environmental health science, we are learning that exposure to toxic chemicals (at levels once thought to have been safe) is increasing the  chronic disease burden for millions of us.  For more information about this disturbing concept,  check out the National Institute of Environmental Health Sciences, part of the National Institutes of Health.
  • The application of these chemicals uses lots  of water. In fact, the textile industry is the #1 industrial polluter of fresh water on the planet.[3] These wastewaters are discharged (largely untreated) into our groundwater with a high pH and temperature as well as chemical load.  I wrote about a documentary which catalogues the ravages brought on by water pollution and how it impacts those downstream, called (interestingly enough), DOWNSTREAM.

We are all downstream.


[1] 24thsession of the FAO Committee on Commodity Problems IGG on Hard Fibers of the United Nations

[2] “Improving profits with energy-efficiency enhancements”, December 2008,  Journal for Asia on Textile and Apparel,  http://textile.2456.com/eng/epub/n_details.asp?epubiid=4&id=3296

[3] Cooper, Peter, “Clearer Communication,” Ecotextile News, May 2007.

(4)  from Annika Carlsson-Kanyama and Mireille Faist, 2001, Stockholm University Dept of Systems Ecology, htp://organic.kysu.edu/EnergySmartFood(2009).pdf

Embodied Energy in production of various fibers + processing:
beach image energy use in MJ per KG of fiber: energy use in MJ per KG of fabric TOTAL energy use in MJ per KG of fabric to produce fiber + weave into cloth
flax 10 92 102
Cotton, convt’l. 55 92 147
wool 63 92 155
Viscose 100 92 192
Polypropylene 115 92 207
Polyester 125 92 217
acrylic 175 92 267
Nylon 250 92 342




What about using organic fabrics in the carbon footprint calculation?

9 06 2009

I’m so glad you asked!

From the previous post I hope I made it clear that natural fibers (whether organic or conventionally produced) have a lighter footprint than do synthetics – both in terms of emissions of greenhouse gasses and in terms of energy needed to manufacture the fibers.  And natural fibers have the added benefits of being able to be degraded by microorganisims and composted,  and  also of sequestering carbon.  According to the United Nations, they’re also a responsible choice, because by buying natural fibers you’re supporting the economies of many developing countries and supporting the livelihoods of many low-wage and subsistence workers.  The United Nations has declared 2009 the Year of Natural Fibers and they have a great website if you’re looking for more information:  http://www.naturalfibres2009.org/en/index.html

Substituting ORGANIC fibers for conventionally grown natural fibers is not just a little better but lots better in all respects:  uses less energy for production, emits fewer greenhouse gases, and supports organic farming (which has myriad environmental, social and health benefits).  A study published by Innovations Agronomiques  (http://www.inra.fr/ciag/revue_innovations_agronomiques/volume_4_janvier_2009) found that fully 43% less greenhouse gasses are emitted per unit under organic agriculture than under conventional agriculture.  A study done by Dr. David Pimentel of Cornell University found that organic farming systems used just 63% of the energy required by conventional farming systems, largely because of the massive amounts of energy requirements needed to synthesize nitrogen fertilizers.  Further, it was found in controlled long term trials that organic farming adds between 100-400KG of carbon per hectare to the soil each year, compared to non-organic farming.  When this stored carbon is included in the carbon footprint calculation, it reduces total greenhouse gasses even further. The key lies in the handling of organic matter (OM): because soil organic matter is primarily carbon, increases in soil OM levels will be directly correlated with carbon sequestration. While conventional farming typically depletes soil OM, organic farming builds it through the use of composted animal manures and cover crops.

Slide1

Taking it one step further beyond the energy inputs we’re looking at, which help to mitigate climate change, organic farming helps to ensure other environmental and social goals:

  • eliminates the use of synthetic fertilizers, pesticides and genetically modified organisims (GMOs) which is not only an improvement in human health and agrobiodiversity but also for the associated off farm biotic communities
  • conserves water (making the soil more friable so rainwater is absorbed better – lessening irrigation requirements and erosion)
  • ensures sustained biodiversity
  • and compared to forests, agricultural soils may be a more secure sink for atmospheric carbon, since they are not vulnerable to logging and wildfire.

Agriculture is an undervalued and underestimated climate change tool that could be one of the most powerful strategies in the fight against global warming, according to Paul Hepperly, Rodale Institute Research Manager. The Rodale Institute Farming Systems Trial (FST) soil carbon data (which covers 30 years)  shows conclusively that improved global terrestrial stewardship–specifically including regenerative organic agricultural practices–can be the most effective currently available strategy for mitigating CO2 emissions. (http://www.rodaleinstitute.org/files/Rodale_Research_Paper-07_30_08.pdf

So just how much CO2 can organic farming take out of the air each year?  According to data from the Rodale Institute Farming Systems Trial (FST) :

  • If only 10,000 medium sized farms in the US converted to organic production, they would store so much carbon in the soil it would be equivalent to taking 1,174,400 cars off the road.
  • If we converted the U.S.’s 160 million acres of corn and soybeans to organic, we could sequester enough carbon to satisfy 73% of the Koyoto targets for CO2 reduction in the U.S.
  • Converting U.S. agriculture to organic would actually  wipe out the 1.5 trillion pounds of CO2 emitted annually and give us a net increase in soil carbon of 734 billion pounds.

carbon sequestratioon image 1

Paul Hepperly says that organic farming is a no brainer:  “Organic farming is not a technological fix, not an untried experiment that could have its own unforeseen consequences.” Instead, it may well be one of the most powerful tools we have in our fight against global warming that brings with it a wealth of other environmental benefits.





carbon footprints…

2 06 2009

Please be aware that our suggestions are just starting points for you to consider when looking at a fabric, because actually calculating a carbon footprint is very complex and time consuming.  Peter Tydemers, who is an ecological economist at Dalhousie University in Nova Scotia, has warned that many of the energy calculators we see should be taken with a pinch of salt – because every detail of where and how something is produced can change and therefore affect the outcome. For example, simply changing an animals feed can have an influence on its CO2 footprint. “It’s all very fluid”, he says, “There’s a tremendous hunger for these sorts of numbers and this has created the assumption that any existing figures are robust. They’re not.” We suggest that you examine carefully any studies to see the variables and the assumptions  made.  Something else to determine is who funded the study!  I was really perplexed to see a web site which had “data” on the energy used to create various fibers; the conclusions being drawn were just a bit outside the limits of any studies I had seen earlier.  But when I saw the industry group that funded the study it all became clear.

That being said, to begin to evaluate the carbon footprint of any fabric the first thing you have to do is  figure out what the fabric is made of  – the fiber.    The fiber tells you a lot about the energy needed to make the yarns, and then the fabric.  The energy needed to produce different fibers varies a lot.

To make it easy to compare the fibers, I”ll divide them into two types: “natural” (from plants, animals and – less commonly – minerals), and “synthetic” (man made)

For synthetics, it’s important to remember that most synthetic fibers  started as fossil fuel, an inherently non renewable resource.  Very high amounts of energy are needed to both extract the oil from the ground as well as to produce the polymers (as it is done under high temperatures).

For natural fibers you must look at field preparation, planting and field operations (mechanized irrigation, weed control, pest control and fertilizers (manure vs. synthetic chemicals)), harvesting and yields.  Synthetic fertilizer use is a major component of the high cost of conventional agriculture:  making just one ton of nitrogen fertilizer emits nearly 7 tons of CO2 equivalent greenhouse gases.

A study done by the Stockholm Environment Institute on behalf of the BioRegional Development Group  concludes that the energy used (and therefore the CO2 emitted) to create 1 ton of spun fiber is much higher for synthetics than for hemp or cotton:

KG of CO2 emissions per ton of spun fiber:

crop cultivation

fiber production

TOTAL

polyester USA

0.00

9.52

9.52

cotton, conventional, USA

4.20

1.70

5.89

hemp, conventional

1.90

2.15

4.10

cotton, organic, India

2.00

1.80

3.75

cotton, organic, USA

0.90

1.45

2.35

The table above only gives results for polyester; other synthetics have more of an impact:  acrylic is 30% more energy intensive in its production than polyester and nylon is even higher than that.

Not only is the quantity of GHG emissions of concern regarding synthetics, so too are the kinds of gasses produced during production of synthetic fibers.  Nylon, for example, creates emissions of Nitrous Oxide,  N2O, which is 300 times more damaging than CO2.[1] In fact, during the 1990s, N2O emissions from a single nylon plant in the UK were thought to have a global warming impact equivalent to more than 3% of the UK’s entire CO2 emissions.[2] A study done for the New Zealand Merino Wool Association shows how much more total energy is required for the production of  synthetics than any natural fibers:

Energy used in production of various fibers:

energy use in MJ perKG of fiber:
flax fibre (MAT)

10

cotton

55

wool

63

Viscose

100

Polypropylene

115

Polyester

125

acrylic

175

Nylon

250

SOURCE:  “LCA: New Zealand Merino Wool Total Energy Use”, Barber and Pellow,      http://www.tech.plym.ac.uk/sme/mats324/mats324A9%20NFETE.htm

Natural fibers, in addition to having a smaller carbon footprint in the production of the spun fiber, have the benefit of

  1. being able to be degraded by micro-organisms and composted; in this way the fixed CO2 in the fiber will be released and the cycle closed.  Synthetics do not decompose.
  2. sequestering carbon.  Sequestering carbon is the process through which CO2 from the atmosphere is absorbed by plants through photosynthesis and stored as carbon in biomass (leaves, stems, branches, roots, etc.) and soils.

As I said, looking at the production of the fiber is just the first part of the equation.  It is clear that, in terms of energy use and CO2 emissions, synthetics are  significantly higher in both cases than any natural fiber.  How the fibers are grown or managed also makes a huge contribution to energy use, and as you might have suspected, organic methods improve these results even more and widen the gap between synthetic and natural fibers.  That’s next week’s topic.


[1] “Tesco carbon footprint study confirms organic farming is energy efficient, but excludes key climate benefit of organic farming, soil carbon”, Prism Webcast News, April 30, 2008, http://prismwebcastnews.com/2008/04/30/tesco-carbon-footprint-study-confirms-organic-farming%E2%80%99s-energy-efficiency-but-excludes-key-climate-benefit-of-organic-farming-%E2%80%93-soil-carbon/

(2) Fletcher, Kate, Sustainable Fashion and Textiles,  Earthscan, 2008,  Page 13