This is from an article by Brooke Bauman, per Yale Climate Connections at https://yaleclimateconnections.org/2019/08/how-plastics-contribute-to-climate-change/.  The following areas are of particular concern:

Waste management affects community health

Globally, about 40% of plastics are used as packaging. Usually, packaging is meant for a single use, so there’s a quick turnaround to disposal. This packaging can be processed in three different ways: landfill, incineration, or recycling.

Waste incineration has the largest climate impact of the three options. According to the CIEL report, U.S. emissions from plastics incineration in 2015 were 5.9 million metric tons of carbon dioxide equivalent. Based on projections from the World Energy Council, if plastics production and incineration increase as expected, greenhouse gas emissions will increase to 49 million metric tons by 2030 and 91 million metric tons by 2050.

The climate impact isn’t the only concern. Incineration facilities are disproportionately built near communities of color and low-income populations.

“Incineration is a massive environmental injustice – not just in the United States, but all over the world,” Arkin said. “The people who are subjected to the pollution from these incinerators often are the ones who are least responsible for the waste in the first place and have to bear the brunt of the impacts.”

Burning waste can release thousands of pollutants. Incinerator workers and people living near facilities are particularly at risk to exposures.

Landfilling has a much lower climate impact than incineration. But the placement of landfills can be associated with similar environmental injustices.

Recycling is a different beast with an entirely different set of problems. Compared to the low costs of virgin materials, recycled plastics are high cost with low commercial value. This makes recycling profitable only rarely, so it requires considerable government subsidies.

Research from the Ellen MacArthur Foundation suggests that only 2% of plastics are recycled into products with the same function. Another 8% are “downcycled” to something of lower quality. The rest is landfilled, leaked into the environment, or incinerated.

Recycling facilities also commonly receive low-quality materials. Wishful recycling makes people recycle items that they think should be recyclable but are actually not. This puts a huge responsibility on the recycling facilities to process and sort the waste.

For many years, the United States and many other Western countries sent a lot of their contaminated waste to China, transferring the responsibility of waste management. In 2018, China closed its doors to the West’s contaminated recycling. Rather than increasing domestic recycling capacity, the United States now sends the waste to other countries like Thailand, Malaysia, and Vietnam. But some of these countries have started to turn down Western recycling, too.

Recycling could be an important bridge on the way to waste reduction, but Arkin said the Western world needs to address its plastics addiction at the source. “We can’t recycle our way out of the plastic pollution crisis,” Arkin said. “There’s simply too much plastic – single-use plastic – being produced and consumed.”

When plastics enter the environment, they don’t stop polluting

After plastics have been used, people may dump them into the environment, sometimes purposefully and other times accidentally. Even if plastics go to a landfill, some are light enough to blow in the wind and enter waterways.

Plastics can break down into smaller pieces, called microplastics, through biodegradation or exposure to the sun, heat, or water. These microplastics scatter across the globe, even to the depths of the ocean. Toxic chemicals can bind to microplastics and create poison pills that aquatic animals eat. Plastics also harm animals through entanglement and ingestion at all levels of the food chain.

Sarah-Jeanne Royer at Scripps Institution of Oceanography has found that low-density polyethylene – one of the most common types of plastics found in the ocean – releases greenhouse gases as it breaks down in the environment.

But beyond the direct emissions from plastics in the environment, there’s another issue with microplastics. Historically, the ocean has sequestered 30-50% of carbon dioxide emissions from human-related activities. However, evidence suggests that plankton are ingesting ever-greater quantities of microplastics.

Researchers at the Ocean University of China found that microplastics reduced the growth of microalgae and the efficiency of photosynthesis. So producing more microplastics could degrade plankton’s ability to remove carbon dioxide from the atmosphere.

What is the solution?

For every phase of the plastics life cycle, there are ways to reduce emissions. But it may take systemic shifts to slow the growth of plastics production. For example, some advocate for using bio-based feedstocks to reduce emissions in the refining stage. According to 2018 analysis by Material Economics – a sustainability management consulting firm – using only zero-carbon energy sources, such as wind and solar, in the manufacturing phase would decrease overall emissions by 50%. That may not be enough to offset emissions associated with the rapid rise of plastics production.

When developing solutions, it’s important to think critically about the materials that will replace plastics. Authors of a 2011 study from the Environment Agency in the United Kingdom assessed the life cycle environmental impacts of different bags – such as paper, plastic, and cotton – used in U.K. grocery stores. Their study found that the key to reducing global warming impact is to reuse the bags as many times as possible. But the number of times the bag must be reused depends on the material it’s made from. The paper and cotton bags need to be reused three and 131 times respectively to ensure their global warming potential is lower than a typical plastic grocery bag.

Ultimately, cutting emissions associated with plastics may require an all-of-the-above strategy: reducing waste, retaining materials by refurbishing or remanufacturing, and recycling. Under this type of circular business model, authors of the CIEL report say carbon dioxide emissions would decrease by 62 million metric tons per year.

Brooke Bauman is an intern at YCC and a student at UNC-Chapel Hill studying environmental science, geography, and journalism.