In the previous Plastic Perspective post, we discussed how emissions from various steps in the plastic production and disposal cycle contribute to health issues, especially amongst the communities that are located nearest to production plants, landfills, and incinerators. These same processes lead to additional impacts on our environment, sending dangerous greenhouse gasses into the atmosphere and further contributing to climate change.
The Greenhouse Effect
Earth’s climate is largely influenced by how much of the sun’s energy is absorbed or reflected back into space; when more energy is absorbed or when gases in the atmosphere prevent the heat from escaping, the earth warms. Those gases in the atmosphere that can trap heat are called “greenhouse gases.”
Though greenhouse gases, such as carbon dioxide and methane, are naturally occurring, records show that the climate warming the planet has been experiencing since the mid-1900s cannot be explained solely by natural processes. Humans produce greenhouse gases through a number of different processes and industries, leading to an increase in concentrations of carbon dioxide, methane, and nitrous oxides that have been unprecedented in the last 800,000 years.
Normally, greenhouse gases would be absorbed by plants and our oceans through photosynthesis and other processes, but these natural processes cannot keep up with the rise in emissions, leading to a buildup of greenhouse gases and an alarming degree of warming.
A report from the Center for International Environmental Law (CIEL) showed that greenhouse gas emissions are released at each stage in plastic’s lifecycle -- during the extraction and transport of fossil fuels, the refining and manufacturing process, the management of plastic waste, and plastic’s ongoing impact when it enters into the environment.
Extraction and Refinement
Extraction of oil and gas, the substances that plastics are made out of, is a highly carbon-intensive process which leads to an estimated 12.5-13.5 million metric tons of carbon dioxide per year (just for the plastic industry alone!). Extraction of these materials also requires companies to clear land, getting rid of the forests that are necessary to recapture the greenhouse gases that are released into the atmosphere.
Refining plastic is a process that is not only one of the most greenhouse-gas intensive amongst all manufacturing-sector industries, it is also the fastest growing. Across the globe, emissions of CO2 from the production of ethylene, a building block for polyethylene plastics, are predicted to increase by 34% between 2015 and 2030. Current levels of plastic production lead to greenhouse gas emissions that threaten the ability of the global community to keep global temperatures from rising above 1.5 degrees celsius.
Disposal and Waste
When plastics are thrown away, they mostly end up in landfills or are sent to incinerators to be burnt for energy; very few plastics are truly recycled. Incineration constitutes the primary driver of emissions from plastics waste management; in 2015 the US emissions from plastic incineration were estimated to be 5.9 million metric tons of CO2e.
About 8 million tons of plastic waste also enters into our oceans each year -- a figure that is thought to be double that by 2030. Our oceans are the largest natural carbon sink for greenhouse gases, but plastic waste in the waters smothers marine animals and habitats while sunlight and heat cause the plastic to emit greenhouse gases. This causes a continuous cycle of increasing heat, increasing breakdown of plastics, and increasing emission of greenhouse gases.
The climate crisis we are facing as a planet today is a threat around the world. If global temperatures rise by 2 degrees celsius, that could lead to rising sea levels, extreme heat waves, flooding, and loss of arctic ice. The lifecycle of plastics is intimately linked to greenhouse gas emissions and, therefore, increasing temperatures. It is imperative, then, that we think about plastics use when we think about climate change.
There are a number of key steps that can be taken to decrease plastic’s impact on our climate: