Global production and consumption of plastics has increased by 10% annually, from 5 million tonnes in 1950 to 245 million tonnes in 2006. In the UK, approximately 5 million tonnes of plastic are used every year and consumption is increasing at a rate of 1.5% a year. An estimated 56% of all plastic waste is used packaging, three-quarters of which is collected from households.
Petroleum-based plastics do not biodegrade. Organic matter such as wood, grass, and food scraps are all broken down by bacteria. However, these helpful bacteria do not recognise plastics as food so they will never biodegrade. Plastics have only been around for about 50 years so no one knows for sure how long plastic will last for though it has been estimated that a plastic bag can remain intact for up to 10,000 years.
Plastic waste has a huge detrimental affect on wildlife. Plastic debris causes the deaths of more than a million seabirds every year, as well as more than 100,000 marine mammals. Syringes, cigarette lighters and toothbrushes have been found inside the stomachs of dead seabirds, which mistake them for food.
When plastics are broken down by sunlight they produce micro-plastic granules and release toxic chemicals such as bisphenol A (BPA) and PS oligomer. This toxic photodegradation is the fate to most plastics which are left floating in the sea. The tiny plastic granules are ingested by marine animals where the release of toxic chemicals can disrupt the functioning of hormones and seriously affect reproductive systems.
The majority of plastics in use as packaging are petroleum-based, which means that they are made from hydrocarbon chains which come from distilled crude oil. Our continued use of plastics in everyday life contributes to an increasing global demand for crude oil. It is estimated that 8% of the world’s annual oil production is consumed in the production of plastics; 4% are used as a raw material and an additional 4% are consumed in the form of fuel or energy during manufacture. Increasing demand for crude oil puts pressure on oil companies to drill for oil in places such as the Arctic which is bad news for everyone (including the polar bears).
Pollution from plastic is has huge implications for the global economy. Ocean plastic pollution costs $13 billion a year, and the annual environmental damage from plastic use in consumer goods is estimated at $75 billion.
Petroleum-based plastics are starting to be replaced by bioplastics that are synthesized from corn or other plant derivatives. The fact that bioplastics can degrade into natural compounds make them a potential sustainable replacement for petroleum-based plastics. However, they will only degrade sustainably if disposed of properly. A photodegradable plastic product will not degrade if it is buried in a landfill site where there is no light, instead it will break down anaerobically producing large amounts of methane (a greenhouse gas 23 times more potent than CO2). There are no facilities for recycling bioplastics at the moment so they currently all end up in a landfill at the end of their useful lives.
Recycling of plastics reduces the global impact of plastic use. However, recycling of plastics is currently very limited. There are about 7 types of plastic that you find in day to day life but only 2 of these are commonly recyclable, the other 5 usually end up in landfills. The recycling industry is also has economical limitations; it costs $4,000 US to recycle one ton of plastic bags, but a ton of recycled bags only sells for $32!