Plastic pollution and climate change are two sides of the same extractive coin. Though the commonly-understood impacts may seem different-- plastic accumulation in oceans and marine life vs carbon emissions heating up the atmosphere-- plastic contributes to climate change at every step of its life cycle, from production through pollution. This blog explores the climate impacts of plastic production, the climate impacts of dealing with plastic waste, and the ramifications for the world’s carbon budget if plastic production continues to increase.
Plastic production is a fundamentally emissions-intensive process in every way, from extraction to refinement. In the United States, natural gas is the main source of ethane feedstock and plastic production. Natural gas (and crude oil) extraction is itself a major source of carbon emissions, from the deforestation that occurs while clearing land to make room for drilling equipment to the methane emitted via flaring and leaking during the fracking process itself, a greenhouse gas 20 times more potent than carbon dioxide. In 2015, emissions from extraction and transport for plastic production were 9.5-10.5 million metric tons of CO2 in the U.S. alone, equivalent to the emissions of 2.1 million passenger cars driven for a year.
Outside of the United States, where oil is the primary feedstock for plastic production instead of natural gas, “approximately 108 million metric tons of CO2e per year are attributable to plastic production, mainly from extraction and refining” according to a comprehensive 2019 study from the Center for International Environmental Law.
The refining process is a similarly prolific source of emissions. “Steam cracking” is the first step in refining feedstocks like ethane and naphtha into actual plastics, and it’s extremely energy-intensive. To split ethane into smaller hydrocarbons that can be re-formed into usable outputs, “cracker” refineries send the feedstock through steam cracker furnaces, where it is heated to between 750°C and 1,100°C. Owing primarily to the amount of energy (and thus fossil fuel) needed to heat these furnaces, annual emissions from just two cracker facilities (a new Shell ethane cracker near Pittsburgh and an ExxonMobil ethylene plant in Baytown, TX) are the equivalent of 800,000 cars on the road, and these are only two of over 300 planned petrochemical facilities in the US dedicated to producing plastic. Unfortunately, transitioning to 100% renewable energy sources for plastic production’s estimated demands would reduce the overall emissions from the process by only half .
The carbon footprint of plastic doesn’t stop at the extraction, refinement and production process. All of that plastic has to end up somewhere, and all of the pathways result in further emissions. Only 9% of plastic produced since 1950 has ended up recycled, while 12% has been incinerated. Though less carbon-intensive than incineration, recycling plastic requires burning fossil fuels to power recycling facility machinery, while incinerating plastic directly produces considerable amounts of greenhouse gases. The climate impact of plastic waste incineration in the US is equivalent to “1.26 million passenger vehicles driven for one year, or more than half a billion gallons of gasoline consumed."
Finally, though currently less clearly defined than emissions from incineration, “disposing” of plastic waste by landfilling or, worse, open littering produces carbon emissions over time due to exposure to solar radiation.
What is the cumulative impact of the plastic life-cycle on carbon emissions, and how does it square with the world’s imperative to reduce carbon emissions as quickly as possible? The 2019 CIEL study estimated that, if growth in plastic production and incineration continue as planned by oil and gas majors, “their cumulative greenhouse gas emissions by 2050 will be over 56 gigatons CO2e, or between 10–13 percent of the total remaining carbon budget."
As the world faces an unprecedented challenge in reducing greenhouse gas emissions, increased plastic production takes us in the exact wrong direction, continuing fossil fuel extraction and consumption and increasing emissions from the plastic production process at the very time we need to be reducing both carbon emissions and the amount of plastic in the world.
On the bright side, reducing plastic production and turning off the plastic tap will bring double the benefits, for the world’s marine life and climate alike. It’s past time to do so.
Big thanks to the Center for International Environmental Law for their comprehensive report, "Plastic and Climate: the Hidden Costs of a Plastic Planet." We highly recommend reading the full report.
Image by Ralf Vetterle from Pixabay