In part 1 of this article, we looked at the current status of plastic waste in the world, and some initiatives which have been introduced in order to reduce plastic waste. This part looks at the many forms of plastic which exist, in particular at non-petroleum-based plastic products and the potential environmental benefits of using these. In the third part, I will go deeper into the plastic issue, exploring the possibility that our careless attitude towards plastic could be indicative of a profound collective psychological rift, and look at ways we can address this.
What is biodegradable?
Most readers may already be aware of the definition of plastic as ‘non-biodegradable’. If a creature or plant is biodegradable, it means that once it is dead or disposed of it can be decomposed by bacteria, and the material can be changed into something new and living which helps to nourish other nodes in the surrounding ecosystem (1). Most living things and human-made substances made from plant-based materials act in this way, so that, within an ecosystem which contains biodegradable elements, there cannot be said to be any waste produced, since everything is changing into everything else in a beautiful cycle.
In this sense, the very concept of ‘waste’ can be seen as a human invention, which, as we know from permaculture thinking, does not have to exist in any system, since we can find an element which requires the so-called ‘waste’ in almost any case (for more on this see for example 2).
Is plastic biodegradable?
The process of biodegradation usually takes between a few months and a few years, from the moment that decay begins until the point where the original material cannot be said to exist at all any longer (3). Environmental factors of course play a part in the length of time; we can shorten the decomposition process ourselves by creating optimum conditions such as with the creation of compost, some designs of which, like the Berkeley hot-composting method, can biodegrade even large items such as bones in a matter of weeks (4).
By throwing our waste into landfill we create far from optimum conditions, which, as well as meaning that our waste takes longer to biodegrade and return to the ecosystem (one report states that in landfill, a lettuce leaf will take 25 years to decompose (5), rather than a few weeks in a compost pile), often involves anaerobic decomposition (without oxygen) wherein the biodegrading waste produces methane, a harmful gas (5). This is arguably completely avoidable. Even in optimum biodegrading conditions, with materials such as glass, aluminium and plastic, we have lengthened the decomposition process substantially (3).
Most humans define petroleum-based plastic, made out of polymers, as ‘non-biodegradable’, meaning that however long you leave it somewhere, no bacteria will break it down. Rather, plastic is defined as ‘photodegradable’ (1) meaning that it can only be broken down by UV radiation from light. If the plastic is left in the ground, the light does not reach it quickly, so the decomposition process is said to take around 1000 years (3,5) (though plastic in its current form has not existed for that long, so it seems this number can only be said to be an estimate).
Though plastic is created by humans, it is derived entirely from our planet, and in this sense can be said to be as natural as anything else in the ecosystem. It is just that it behaves in a different way from other materials, so treating it as biodegradable and throwing it into the ground is not generally beneficial to the soil.
True to the ‘Produce No Waste’ principle and finding ways to use waste as a resource, there have recently been discoveries of certain types of bacteria which can decompose plastics (1). Indeed, so-called extremophile bacteria can even help to break down nuclear waste (6). In this sense, all plastic is indeed biodegradable as well as photodegradable, it is just that the particular type of bacteria required for the decomposition process are not readily available in most places, so it is still harmful to the environment to simply leave it in the ground.
According to Marine Conservancy, around 150 million metric tonnes of plastic are in the world’s oceans right now, with an extra 8 million metric tonnes being added every year (7). Since plastic in the ocean is exposed to UV radiation almost continuously, most forms of plastic which are in the ocean can photodegrade within one year (1). This may seem positive for the oceanic ecosystems, but the decomposition process releases BPA chemicals into the water which are toxic to may lifeforms, including humans (1). It seems theoretically possible that, given we have discovered the bacteria to biodegrade plastic, that we could introduce this bacteria to the mounds of plastic waste which are currently piling up in the world’s great oceans, and thus help to transform them from floating islands of slowly breaking-down toxic chemicals to ones on which plant and maybe eventually animal life could thrive (8). Until we have this technology, however, it seems safer to stop throwing plastic into the oceans.
If we cannot dispose of plastic safely in the ground or in the sea, it seems clear that we need to find an alternative to the material itself. So-called biodegradable plastics made from non-petroleum products are currently part of a growing global industry (9). Firstly, it seems important to note that, as with anything touted as ‘alternative’, doing research into the actual means and production is essential if we are to be sure that the alternatives are indeed more environmentally-friendly than those methods already in use. There are a number of plant-based plastics which can be seen as just as damaging to the environment as petroleum-based; and some which are perhaps more holistic.
Many corporations already produce ‘bioplastic’ packaging or products, made of a range of plant-based materials (9). However, the use of bioplastics has raised a lot of concerns about the actual viability of the materials breaking down. Just because they are made of plants, it does not necessarily mean they are able to be composted easily; after all, petroleum itself is originally composed of plants (10). For example, the Coca-Cola corporation, which was revealed by Greenpeace in 2017 as being responsible for over 100 billion plastic throwaway bottles every year (11), recently started selling some of their drinks in a ‘PlantBottle’, made of plastic derived originally from sugarcane. However, the actual material is “chemically identical to hard-to-breakdown polyethylene terephthalate (PET) bottles [so] it won’t breakdown for centuries.” (9).
Sugarcane and cornstarch are the main ingredients being experimented with on a mass scale for plant-based plastic production (9, 12), which also raises questions of the enviornmental damage if such materials are produced using large-scale intensive industrial monoculture. Also, if we are to ensure that we can produce food and encourage healthy ecosystems, it seems that it would be better to encourage land use for food production rather than plastic production.
In order to truly turn the problem into a solution, it seems important that we look at which alternatives are actually more beneficial to the ecosystem. Two potential plant-based plastics which may fit this are Prickly Pear and seaweed.
The use of the Prickly Pear cactus (Opuntia spp) was discovered last year by Mexican scientist Sandra Pascoe, using the most common edible varieties, Opuntia Ficus-Indica and Opuntia Megacantha (13).
Anyone who has lived in an ecosystem featuring these spiky plant-friends has probably had experience, as well as the sweet juicy fruits, of the clear, sticky, almost glue-like juice which can be obtained from the leaves. This juice seems incredibly durable and I have even known people to experiment with it as an alternative to cement in natural building, so it seems a very fitting candidate as a plastic alternative too.
The benefits of using Opuntia instead of sugarcane or cornstarch would be that, since it is a plant suited to an arid climate (14), it requires much less water than the other crops. Also, since the plastic is derived from the leaves, and the parts which humans normally eat are the fruit (13, 14), the plant could be harvested for both uses at the same time. The Opuntia plastic was found to decompose in water and soil, though further tests are being carried out to ensure that the decomposition process is non-toxic (13).
Taking plastic from the sea?
Seaweed-based plastic is another material which is safer to dispose of. Some reports show that plastic made from seaweed can decompose in the soil and water without releasing toxic chemicals, and when placed in the soil, can actually increase soil fertility (15). From an economic point of view, this means that as a product, seaweed-based plastic could be used once as packaging, and then recycled and re-sold as plant fertiliser (15), making it a very attractive material.
Seaweed-based plastic production is currently being explored in Indonesia, the country “with the largest archipelago in the world” (12), and the world’s largest producer of Red Seaweed, Eucheuma Cottoni (12). Seaweed-based plastic is also seen as attractive as growing seaweed would not take up any space on the land which could be used for human food production (12).
With both of these biodegradable alternatives, we would have to be very careful about the means of production if they were to become as large an industry as petroleum-based plastic. Turning huge areas of coastline into a Red Seaweed monoculture would probably not be very beneficial to the current existing marine ecosystems.
Indonesia currently has 216 Marine Protected Areas (16), and it seems vitally important that we continue to view protecting ocean-life as important, even if we can also use parts of the ocean for our own products. In the same way, Opuntia monocultures, if managed inefficiently, may not be that beneficial to land-based ecosystems either.
Making plastic out of waste
As explored above, plant-based plastics as an industry may have some negative impacts on the environment, though they are probably far more beneficial than current mainstream plastic production methods. With any product made from a raw material, there is always the problem of exploitation of the environment in order to produce that material. However, if the material itself has a so-called ‘waste’ source, this problem does not exist. For example, producing plastic made of used coffee grounds (17).
Coffee is the most popular drink on the planet (18); apparently we globally consume around 400 billion cups of this potent black medicinal drink every year, and chances are that as you read this, you are drinking some right now. The coffee-based plastic as explored by C2Renew company (17) is made of coffee grounds which would otherwise be thrown away, so it is not adding anything extra into the ecosystem. It may, of course, raise the question of coffee production in the first place and if the production methods are sustainable. One possible benefit is that since coffee is a shade-loving plant, it is often intercropped with other species (see for example 18) and so can be said to be possibly more holistic than crops which are grown using only monocultural methods.
In conclusion, we currently have the technology to produce plastic in a safer and more holistic way than is currently the case, as well as exciting possibilities for biodegrading even so-called ‘non-biodegradable’ plastic. Yet even if we do eventually replace all our plastic with material which can more readily re-enter into the ecosystem, we may still be creating an imbalance, since we currently consume such a huge amount of this material. It seems essential that we address this dependence and if possible find new ways of relating to plastic, which is what I will explore in part 3 of this article.
- Harris, W, 2010. “How long does it take for plastics to biodegrade?”
- Kaplan, R, 2012. ‘Permaculture Principle 6: Produce No Waste’. Urban Homesteading. http://urban-homesteading.org/principle-6-produce-no-waste/
- Science Learning Hub – Pokapū Akoranga Pūtaiao, 2008. ‘Measuring Biodegradability’. https://www.sciencelearn.org.nz/resources/1543-measuring-biodegradability
- Ashwanden, C, 2015. ‘Some Tips on Making Compost’. Permaculture News, 15/9/15. https://permaculturenews.org/2015/09/15/some-tips-on-making-compost/
- Tapan, M, 2019. ‘Nature can’t do it all: how long does it take for our waste to decompose?’ Daily Sabah, 23/1/19. https://www.dailysabah.com/feature/2019/01/23/nature-cant-do-it-all-how-long-does-it-take-for-our-waste-to-decompose
- University of Manchester, 2014. “Nuclear waste eaters: Scientists discover hazardous waste-eating bacteria.” ScienceDaily. ScienceDaily, 9/9/14. www.sciencedaily.com/releases/2014/09/140909093659.htm
- Ocean Conservancy, 2019. ‘Trash Free Seas: Plastic in the Ocean’. https://oceanconservancy.org/trash-free-seas/plastics-in-the-ocean/
- Ashwanden, C, 2019. ‘The Haunted Beach’. Abundance Dance Garden, 24/5/19. https://abundancedancegarden.wordpress.com/2019/05/24/story-the-haunted-beach/
- Boyd, O, 2017. ‘The Plastics Problem: Are natural alternatives doing more harm than good?’ The Guardian, 31/10/17. https://www.theguardian.com/business-to-business/2017/oct/31/the-plastics-problem-are-natural-alternatives-doing-more-harm-than-good
- Oil Price, 2019. ‘What is Crude Oil? A Detailed Explanation on this Essential Fossil Fuel’. https://oilprice.com/Energy/Crude-Oil/What-Is-Crude-Oil-A-Detailed-Explanation-On-This-Essential-Fossil-Fuel.html#
- Rodionova, Z, 2017. ‘Coca Cola produces over 100 billion disposable plastic bottles, according to Greenpeace.’ Independent, 10/4/17. https://www.independent.co.uk/news/business/news/coca-cola-plastic-bottles-cant-be-recycled-greenpeace-statement-a7673246.html
- Sedayu, BB, 2018. ‘Seaweed, Indonesia’s answer to the global plastic crisis’. The Conversation. https://theconversation.com/seaweed-indonesias-answer-to-the-global-plastic-crisis-95587
- Barrett, A, 2018. ‘Bioplastics Made From Cactus’. Bioplastics News, 13/6/18. https://bioplasticsnews.com/2018/06/13/bioplastics-cactus/
- Plants for a Future, 2019. ‘Opuntia Ficus-Indica’. https://pfaf.org/user/Plant.aspx?LatinName=Opuntia+ficus-indica
- Stone, D, 2019. ‘Seaweed Is The New Plastic’. Bold Business. https://www.boldbusiness.com/bold-living/seaweed-new-biodegradable-plastic/
- Atlas of Marine Protection, 2019. ‘Indonesia’. http://www.mpatlas.org/region/country/IDN/
- Bryman, H, 2015. ‘C2Renew’s Coffee-Based Plastic Can Be Made into Literal Coffee Cups’. Daily Coffee News, 7/9/15. https://dailycoffeenews.com/2015/09/07/c2renews-coffee-based-plastic-can-be-made-into-literal-coffee-cups
- the Editors of Publications International, Ltd, 2008.”Coffee Facts”. HowStuffWorks.com. https://recipes.howstuffworks.com/coffee-facts.htm
- CGIAR Research Program on Climate Change, Agriculture and Food Security (CCAFS), 2016. ‘The Power of Intercropping Banana and Coffee’. Farming First, 5/16. https://farmingfirst.org/2016/05/the-power-of-intercropping-banana-and-coffee/