Are Biodegradable Plastics Truly Eco-Friendly? Unpacking the Facts for a Sustainable Future

October 27, 2024 / activist360

Impact Characterization of Biodegradable Plastics
Credit: Piao, Z., Boakye, A. A. A., & Yao, Y. (2024). Environmental impacts of biodegradable microplastics. Nature Chemical Engineering, 1, 661–669.

When you hear the word “biodegradable,” what comes to mind? Many of us assume biodegradable plastics are a perfect solution for reducing plastic pollution. However, these materials have complex environmental impacts that aren’t immediately obvious. While they can help reduce certain types of pollution, they also come with hidden trade-offs, including greenhouse gas emissions that contribute to climate change.

In this article, we’ll dive into the environmental impacts of biodegradable plastics, explain how Life Cycle Impact Assessment (LCIA) helps scientists understand their effects, and offer tips for more eco-friendly choices.

What Are Biodegradable Plastics?

Biodegradable plastics are materials designed to break down in the environment faster than traditional plastics. They are typically made from renewable resources, like corn starch or sugarcane, or from fossil-based sources. Common types include plant-based PLA (polylactic acid) and fossil-based PCL (polycaprolactone).

To fully understand their impact, scientists use a process called Life Cycle Impact Assessment (LCIA). LCIA evaluates a product’s environmental footprint across its entire life cycle—from production to disposal. This is essential for understanding biodegradable plastics’ real impact on our planet, including factors like greenhouse gas emissions, water pollution, and waste management challenges.

Benefits of Biodegradable Plastics in Reducing Microplastic Pollution

One of the most significant benefits of biodegradable plastics is their potential to reduce microplastic pollution. Microplastics are tiny plastic fragments that pollute our oceans, rivers, and even our food and water. Because they don’t easily decompose, they accumulate in ecosystems and can harm wildlife and human health.

Biodegradable plastics offer a promising alternative. When they break down properly, they are less likely to form these harmful microplastics. Scientists assess this potential benefit through a measure in LCIA called aquatic ecotoxicity, which looks at how materials impact aquatic life. Biodegradable plastics typically score lower in aquatic ecotoxicity than traditional plastics because they break down more completely, reducing the risk of long-term pollution.

Think of biodegradable plastics like “biodegradable litter.” If disposed of properly, they disappear without leaving a trace, unlike conventional plastics that break into microplastics and linger in the environment for years.

The schematic diagram of the LCA methodology for biodegradable plastics

Hidden Costs of Biodegradable Plastics: Greenhouse Gas Emissions

While biodegradable plastics can reduce visible pollution, they aren’t without environmental costs. As these plastics break down, particularly in natural environments like rivers or forests, they can release greenhouse gases (GHGs) like methane—a potent contributor to climate change.

Here’s a surprising statistic: when PCL, a common biodegradable plastic, breaks down in a natural setting, it can emit up to 16.3 kilograms of CO₂-equivalent per kilogram of plastic. This emission rate is about 16 times higher than what it would release in an industrial composting facility.

Scientists use Global Warming Potential (GWP) within LCIA to measure how much a material contributes to climate change. For biodegradable plastics, scientists often use dynamic GWP calculations, which track greenhouse gas emissions over time rather than assuming a constant rate. This approach reveals that biodegradable plastics can emit GHGs in bursts as they break down, especially under anaerobic (low-oxygen) conditions in natural environments.

In some scenarios, biodegradable plastics that aren’t properly managed may actually emit more greenhouse gases than traditional plastics.

Role of Waste Management in Reducing Environmental Impact

The environmental impact of biodegradable plastics depends heavily on how they are disposed of. Ideally, they should be processed in industrial composting facilities, where conditions like temperature and oxygen are carefully controlled to allow these plastics to break down quickly and with minimal greenhouse gas emissions.

However, when biodegradable plastics end up in natural environments, such as lakes or soil, they break down under uncontrolled conditions, leading to increased emissions.

Think of biodegradable plastics as “biodegradable litter.” Just as litter remains litter if tossed on the ground, biodegradable plastics can still pollute if not disposed of correctly.

This brings us to the End-of-Life (EoL) Impact stage in LCIA. LCIA considers the full “end-of-life” cycle of a product to evaluate its environmental footprint based on where it ends up. Without the proper disposal infrastructure, biodegradable plastics may add to environmental pollution rather than reduce it.

What the Future Holds for Biodegradable Plastics

As scientists learn more about the impacts of biodegradable plastics, they’re working to design materials that minimize environmental costs. Using tools like LCIA, researchers can adjust physical properties—such as density, degradation rates, and carbon content—so that biodegradable plastics break down with lower greenhouse gas emissions and reduced aquatic toxicity.

LCIA helps scientists make informed design choices that balance eco-friendliness with practicality. For instance, certain plastics might be designed with an optimized Specific Surface Degradation Rate (SSDR), which controls the rate at which they break down in nature. This helps reduce greenhouse gas emissions while ensuring the plastic still decomposes efficiently.

Think of it like a “recipe” for future plastics. Each ingredient—density, degradation rate, carbon content—needs to be carefully balanced to create a plastic that’s both sustainable and functional. Just as a recipe requires precision for the best result, so does the design of biodegradable plastics.

With LCIA as a guide, scientists and manufacturers can develop low-carbon biodegradable plastics that help protect the planet by reducing pollution and managing emissions.

What Can We Do to Make a Difference?

As consumers, we have a role to play in reducing plastic pollution and supporting sustainable materials. Here are some ways we can contribute:

Mindful Consumption: Choose products with minimal packaging and support companies that use sustainable materials.
Proper Disposal: Make sure biodegradable plastics go into the correct waste streams. Check local composting and recycling guidelines to see if your area has facilities for biodegradable plastics.
Spread the Word: Share this information with friends and family. Understanding the pros and cons of biodegradable plastics helps everyone make more informed, eco-friendly choices.

Summing Up

Biodegradable plastics are a promising step toward reducing plastic pollution, but they also come with their own environmental costs, especially when they end up in natural environments. Through Life Cycle Impact Assessment (LCIA), scientists help us understand these trade-offs, from reducing microplastic pollution to the hidden impacts of greenhouse gas emissions.

Ultimately, while biodegradable plastics offer benefits, they are only part of the solution. Proper disposal methods, innovative material design, and mindful consumer choices are essential to building a sustainable future for our planet.

Source: Piao, Z., Boakye, A. A. A., & Yao, Y. (2024). Environmental impacts of biodegradable microplastics. Nature Chemical Engineering, 1, 661–669. https://doi.org/10.1038/s44286-024-00127-0

Understanding the Global Plastic Pollution Crisis

September 8, 2024 / activist360

Overview of Plastic Pollution and the Role of the Global Plastics Treaty

Plastic pollution is one of the biggest challenges our world faces today. It affects our oceans, rivers, land, and even the air we breathe. Every year, millions of tons of plastic waste end up in the environment, creating serious problems for both people and nature. Let’s dive into the key facts about plastic pollution and the steps being taken to address it through the Global Plastics Treaty.

What is Plastic Pollution?

Plastic pollution happens when plastic waste escapes from managed systems like landfills and enters the environment. When this waste is no longer controlled, it becomes a major threat to ecosystems. Plastic pollution can be broken down into two types:

Macroplastics: These are larger pieces of plastic (greater than 5mm) like bottles, bags, and other visible plastic items.
Microplastics: Tiny plastic particles (smaller than 5mm) that often come from the breakdown of larger plastics.

How Much Plastic Waste is There?

In 2020, around 52.1 million metric tons of macroplastic waste entered the unmanaged environment. This is about 21% of all the plastic waste produced by cities and towns, also known as municipal plastic waste. Municipal plastic waste comes from homes, businesses, schools, and public spaces, according to a global emissions inventory study published in Nature (s41586-024-07758-6).

What is the Unmanaged Environment?

The “unmanaged environment” is any place where plastic waste is no longer being controlled. This includes uncollected waste, litter, and open dumping sites. Once plastic enters this environment, it can move freely and cause harm to wildlife, ecosystems, and even human health.

Why Does Open Burning Happen?

In many parts of the world, especially in developing countries, formal waste collection services are either unavailable or not sufficient. As a result, people resort to open burning of plastic waste as a way to get rid of it. Open burning is harmful because it releases dangerous chemicals into the air and contributes significantly to pollution.

Global North vs. Global South: Who’s Responsible?

When we talk about plastic pollution, the world is often divided into the Global North and the Global South:

The Global North includes wealthier, high-income countries like the United States, Western Europe, and Japan. These countries have better waste management systems and tend to have less uncollected waste.
The Global South includes developing countries in regions like Africa, Latin America, and Southeast Asia. These countries struggle with waste collection, and uncollected plastic waste is a major source of pollution.

Plastic Pollution Hotspots

Certain regions are considered plastic pollution hotspots due to their high levels of unmanaged plastic waste:

Southern Asia, Sub-Saharan Africa, and Southeast Asia have the highest levels of plastic pollution.
India is the largest global emitter, contributing nearly one-fifth of all plastic waste emissions, followed by countries like Nigeria and Indonesia.
In contrast, the Global North has lower levels of pollution because of better waste management practices, though littering is still a problem.

What is the Global Plastics Treaty?

The Global Plastics Treaty is a global agreement being negotiated under the United Nations Environment Programme (UNEP) to tackle plastic pollution. The treaty aims to reduce plastic waste, improve recycling, and promote better waste management worldwide. This treaty brings together representatives from governments, industries, scientists, and environmental groups to find solutions.

Negotiations began in 2023. The next Intergovernmental Negotiating Committee (INC) meeting for the Global Plastics Treaty is scheduled for November 25–December 1, 2024 in Busan, South Korea. This meeting is called INC-5 and is expected to finalize the text of the treaty.

Why Does This Matter?

Plastic pollution has lasting effects on the environment and human health. Once plastic waste enters the environment, it can break down into microplastics, which are even harder to clean up. Without immediate action, plastic waste will continue to harm ecosystems, wildlife, and people.

Call to Action

Plastic pollution is a global issue that needs urgent attention. While some countries have made progress in managing their plastic waste, others face major challenges. The Global Plastics Treaty offers hope for coordinated global action to reduce plastic pollution and protect our planet for future generations. Tackling uncollected waste and improving waste management systems, especially in developing countries, will be key steps toward solving this crisis.

By understanding the sources and impacts of plastic pollution, we can all play a part in making our world a cleaner, healthier place.

What is wishcycling? Two waste experts explain

January 16, 2022 / activist360 / Leave a comment

By Jessica Heiges and Kate O’Neill, The Conversation (CC BY-NC-ND 4.0).

Wishcycling is putting something in the recycling bin and hoping it will be recycled, even if there is little evidence to confirm this assumption.

Hope is central to wishcycling. People may not be sure the system works, but they choose to believe that if they recycle an object, it will become a new product rather than being buried in a landfill, burned or dumped.

The U.S. recycling industry was launched in the 1970s in response to public concern over litter and waste. The growth of recycling and collection programs changed consumers’ view of waste: It didn’t seem entirely bad if it could lead to the creation of new products via recycling.

Pro-recycling messaging from governments, corporations and environmentalists promoted and reinforced recycling behavior. This was especially true for plastics that had resin identification codes inside a triangle of “chasing arrows,” indicating that the item was recyclable – even though that was usually far from the truth. In fact, only resins #1 (polyethylene terephthalate, or PET) and #2 (high-density polyethylene, or HDPE) are relatively easy to recycle and have viable markets. The others are hard to recycle, so some jurisdictions don’t even collect them.

The SPI resin identification coding system is a set of symbols placed on plastics to identify the polymer type. Bonus Unicode & Green Dot Symbol. SourceL Open Clipart Library. — *The SPI resin identification coding system is a set of symbols placed on plastics to identify the polymer type. Bonus Unicode & Green Dot Symbol. Source: Open Clipart Library.*

Wishcycling entered public consciousness in 2018 when China launched Operation National Sword, a sweeping set of restrictions on imports of most waste materials from abroad. Over the preceding 20 years, China had purchased millions of tons of scrap metal, paper and plastic from wealthy nations for recycling, giving those countries an easy and cheap option for managing waste materials.

The China scrap restrictions created enormous waste backups in the U.S., where governments had under-invested in recycling systems. Consumers saw that recycling was not as reliable or environmentally friendly as previously believed.

An unlikely coalition of actors in the recycling sector coined the term “wishcycling” in an effort to educate the public about effective recycling. As they emphasize, wishcycling can be harmful.

Contaminating the waste stream with material that is not actually recyclable makes the sorting process more costly because it requires extra labor. Wishcycling also damages sorting systems and equipment and depresses an already fragile trading market.

Know Your No’s Recycling Informative Postcard – PDF, City of Asheville, N.C. — *Know Your No’s Recycling Informative Postcard,* City of Asheville, N.C.

Huge waste management companies and small cities and towns have launched educational campaigns on this issue. Their mantra is “When in doubt, throw it out.” In other words, only place material that truly can be recycled in your bin. This message is hard for many environmentalists to hear, but it cuts costs for recyclers and local governments.

When in doubt, throw it out.

We also believe it’s important to understand that the global waste crisis wasn’t created by consumers who failed to wash mayonnaise jars or separate out plastic bags. The biggest drivers are global. They include capitalistic reliance on consumption, strong international waste trade incentives, a lack of standardized recycling policies and the devaluation of used resources. To make further progress, governments and businesses will have to think more about designing products with disposal and reuse in mind, reducing consumption of single-use products and making massive investments in recycling infrastructure.