The urgency to find solutions that tackle plastic pollution leverage new technological innovations that aim to reduce our dependence on oil-based plastics. Many of these alternatives are sourced from plants, for example, edible seaweed packaging, 3D printing from corn starch and inedible banana leaves used to wrap perishable food. However, although bioplastics such as these have a smaller carbon footprint than conventional plastics, there is still controversy caused by the fact that not all bioplastics are biodegradable or compostable.
Synthetic polymers
Plastic is versatile, inexpensive and convenient to use. For over 100 years, this innovative material has been unquestionably beneficial for many industries and is considered vital in modern-day society. First developed in the 19th century, the use of plastic accelerated with the development of industrial chemistry during the Industrial Revolution. Plastic has played a role in the majority of industrial sectors, from packaging to medical and pharmaceutical applications, clothing, cars, furniture and toys - plastic is everywhere. But unfortunately, so is the pollution that it causes, particularly in the case of single-use plastic.
In 2018, research revealed that around 380 million tonnes of the material was produced worldwide each year. From the 1950s to 2018, it is estimated that 6.3 billion tonnes of plastic was produced worldwide, of which only 9% was recycled and 12% incinerated. A large amount of plastic waste is disposed of in the sea, harming marine life and damaging habitats and biodiversity. Researchers suggest that by 2050 the weight of plastic in the oceans will succeed that of the fish.
Despite environmental campaigns intensifying as our seas become increasingly polluted, plastic continues to be produced. This begs the question - why, with the information and research readily available, does the amount of pollutants unsustainably discarded change so little? The ever-growing production of plastic can be attributed to population growth worldwide but, in recent years, some governments and industry leaders have introduced policies to ban single-use plastic. Despite this positive change, these commitments will likely reduce the annual flow of plastic pollution by only 7% by 2040. This is not nearly enough.
There are many questions that need to be answered in order to create a long-lasting solution. How can we find a sustainable and reusable alternative to plastic? How do we change the whole complex chain - from production, usage and collection to recycling and reuse? Is recycling the most effective way to reduce the production of virgin plastic?
It remains intangible at this stage to develop a lasting global strategy that is based on creating sustainable raw materials, relying less on fossil resources and reducing carbon emissions. A variety of different proposals surface daily, from the total elimination of plastics to the development of biodegradable substitutes using a circular model. However, each solution comes with its own advantages and disadvantages.
Bioplastics
Many scientists, researchers and material designers are focusing on bioplastics; rather than petroleum, bioplastics are plastics made from plants or other biological material, such as cornstarch, sweet potato, soybean oil, sugarcane, hemp oil or algae. Bio-based materials are promising as their feedstocks are renewable. Theoretically, their production process is more energy efficient than petroleum-based plastics and they can be composted or recycled. While the solution of replacing virgin plastics with bioplastics appears promising, some studies show that it is not as simple as it seems.
Biodegradable plastics are available in many grades with a wide variety of properties and, while many of these plastics can biodegrade, others cannot. For those that can, biodegradation is not a simple process as it requires the high temperatures available in an industrial composting facility. Furthermore, replacing fossil plastics with bioplastics requires fertilisers, pesticides and the expansion of agricultural land. On the flip side, there is abundant research showing that waste resources from existing industries, such as food and agricultural waste, are being utilised as raw materials for bioplastics. In this way, the production of bioplastics can reduce waste emissions and foster a more circular economy.