Why is reducing waste important to fight climate change?
Single-use plastics and other disposables pose a serious threat for several reasons. For the first time, a report in May this year looked at the emissions that stemmed from a complete life-cycle of single-use plastics employing data previously unaccounted for in widely-used climate models.
The authors specifically called out single-use plastics found in packaging and fast-moving consumer goods - not just the largest but also the fastest-growing segment of the plastic economy. They are calling for urgent action to cut loose from single-use and to stem throwaway plastic production. When does single-use plastic emit carbon emissions? With the help of the report by the Center for International Environmental Law (CIEL), we've explained how plastic production contributes to global warming through its greenhouse gas emissions and interference with the environment.
Extraction and Transportation of Fossil Fuels
Fossil fuels are below us, buried in the ground, and the extraction itself of these natural resources produce both direct and indirect emissions. Extraction (oil rigging, fracking) causes leakage of greenhouse gases and in particular methane, a gas that is 80 times more potent than an equivalent amount of carbon dioxide (CO2) according to the Intergovernmental Panel on Climate Change, during the first 20 years it is released into the atmosphere. After this period, methane turns into CO2 lasting hundreds of years more still. The extraction process and then transport of the obtained resources require machinery that relies on energy consumption and fuel combustion. Add to that the clearing of land (natural areas of carbon sinks) and we have increased greenhouse gases while reducing our planet's natural aids to manage them.
Refining Fossil Fuels and Manufacturing of Plastics
According to CIEL's report, plastic refining ranks in the top most greenhouse-intensive and fast-growing industries in manufacturing. Besides the machinery again, emissions come from the forced chemical reaction itself, which we can compare to the emissions produced by vehicles: in 2015 just 24 ethylene facilities (used to create polythene for plastic bags and packaging) emitted as much CO2 as 3.8 million passenger vehicles. Globally, cracking of ethylene emitted as much 45 million passenger vehicles.
Plastic Waste Management
All waste management scenarios create greenhouse gases. From least to most: landfilling (creates other dangers though), recycling (on an absolute level only because reduces use of new resources), and incineration, the primary driver of emissions from plastic waste management and globally poised to spread rapidly in the near future. The alarming estimated global emissions from plastic packaging incineration (which represent over 40% of plastic demand) does not account for the third of plastic packaging waste that remains unmanaged, domestic and open burning, non waste-to-energy type incinerations or other less quantifiable but widespread practices of incineration.
Plastic Fate in Nature
Finally, we now have evidence that plastics deteriorate to release methane and other greenhouse gases and while they remain difficult to quantify, particularly because we estimate the gases released by ocean surface plastics, but not the deep ocean plastic which are expected to represent the majority of ocean plastic. Other than emissions, more and more studies on microplastics in aquatic environments shed light on their potential to contaminate phytoplankton which would threaten the ocean's natural ability to absorb carbon dioxide, thus removing our planet's largest natural carbon sink.