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://www.nature.com/articles/s44286-024-00127-0?error=cookies_not_supported&code=30edf270-5181-43e1-ad25-342ee6f78155

Climate Litigation: A Growing Force in the Fight Against Climate Change

September 22, 2024 / activist360

As the world faces increasingly severe climate impacts, governments and corporations are being held accountable through a surge of climate-related lawsuits. A recent study, Research Areas for Climate Litigation, conducted by the Union of Concerned Scientists (UCS) in September 2024, highlights the critical role of climate litigation in driving action where traditional policy-making has often fallen short.

The Rise of Climate Litigation

Since 2015, more than 1,800 climate-related lawsuits have been filed worldwide, with at least 230 new cases in 2023 alone. The United States, United Kingdom, and Australia have become the primary hubs for this legal activity, while other regions, especially parts of Africa, have seen limited litigation.

The UCS study emphasizes that this growing body of legal action requires strong scientific evidence to be effective. To that end, scientists and researchers are increasingly collaborating with legal teams to provide the necessary data, helping courts make informed decisions on climate cases. The study aims to bridge gaps between science and law by identifying key research priorities that can strengthen future litigation efforts.

Key Research Areas for Climate Litigation

The study highlights three priority research areas that are essential for advancing climate lawsuits:

Attribution Science: This field connects specific climate impacts to particular sources of emissions. Courts need this science to establish a clear causal link between climate change and its effects, such as extreme weather events. The study calls for more geographically diverse research, particularly in regions like the Global South, where climate data is scarce.
Climate Change and Human Health: Legal arguments are increasingly focusing on the health impacts of climate change. Vulnerable groups, including older adults, infants, people with disabilities, and those in poverty, are especially at risk from worsening air quality, heatwaves, and water scarcity. The study points to a need for more research linking climate change to health outcomes like asthma, cardiovascular diseases, and heat-related illnesses.
Economic Modeling: Courts rely on economic data to assess the costs of climate change. This includes not only the direct damages caused by extreme weather events but also the costs of adapting to a changing climate and the economic opportunities lost due to inaction. The study calls for robust economic modeling that can predict future costs and benefits under different climate scenarios.

Strategic Research Areas for the Future

Beyond the priority areas, the study identifies five strategic research areas where further scientific evidence is needed to support climate litigation:

Legal and Financial Accountability: Holding corporations accountable for their emissions, particularly in industries like fashion and cement, requires more detailed research on how financial institutions contribute to climate change by funding fossil fuel projects.
Disinformation and Greenwashing: The study stresses the importance of exposing and countering misleading claims made by corporations about their environmental practices, which can mislead consumers and delay meaningful climate action.
Fair Share Analysis and Compliance: Understanding whether corporations and nations are meeting their climate goals is critical. The study highlights the need for standardized emissions metrics and tracking, especially for corporations with complex supply chains.
Environmental and Social Impacts: Research on how climate change affects ecosystems, biodiversity, and human communities—especially in remote regions with limited data—is vital for comprehensive environmental impact assessments.
Emissions Accounting and Reductions: Courts need better methods for tracking and reducing emissions, particularly those related to the indirect effects of products, known as Scope 3 emissions. The study also calls for research into the effectiveness of renewable energy credits and other mitigation strategies.

Losses and Damages: A Cross-Cutting Theme

One of the study’s most important cross-cutting themes is losses and damages—the economic and non-economic harms caused by climate change that can’t be prevented through adaptation or mitigation. The study calls for more research to quantify these losses, especially in terms of intangible cultural heritage, social structures, and ways of life. Understanding these losses is critical for communities seeking reparations for the damage caused by climate change.

Why This Study Matters

As climate litigation accelerates globally, the need for solid scientific research to support these cases becomes more urgent. The UCS study provides a roadmap for scientists looking to contribute to the legal battle against climate change by focusing on areas where their work can have the greatest impact. This research will not only improve the effectiveness of climate lawsuits but also push governments and corporations to take more meaningful climate action.

Summing Up

Climate litigation is emerging as a powerful tool in the fight against climate change. With over 1,800 lawsuits filed since 2015, the legal community is increasingly relying on science to prove the connections between climate change, its impacts, and the entities responsible. The Union of Concerned Scientists’ 2024 study highlights the critical research areas—such as attribution science, health impacts, and economic modeling—that will strengthen these legal efforts.

For those interested in how climate change is being addressed through legal channels, this study underscores the vital role that science plays in holding governments and corporations accountable. As the impacts of climate change worsen, the importance of this intersection between science and law will only grow.

Source: Merner, L. D., Phillips, C. A., & Mulvey, K. (2024). Research areas for climate litigation: 2024 report. Union of Concerned Scientists.

Climate Change Threatens U.S. Bridges

September 15, 2024 / activist360

Key Findings from a Recent Study

A recent study published in PLOS ONE, authored by Susan Palu and Dr. Hussam Mahmoud, highlights the growing vulnerability of deteriorating U.S. bridges due to climate change. This research, conducted at Colorado State University, focuses on how rising temperatures and clogged expansion joints could jeopardize the structural integrity of thousands of bridges across the country.

The Researchers Behind the Study

Susan Palu was a master’s student in civil engineering when the study was conducted, bringing fresh academic insight into the challenges of aging infrastructure. Dr. Hussam Mahmoud, a professor at Colorado State University and the George T. Abell Professor in Infrastructure, is a renowned expert in sustainable infrastructure and community resilience. With a Ph.D. from the University of Illinois at Urbana-Champaign and over 300 publications to his name, Mahmoud’s research focuses on making infrastructure systems more resilient to natural hazards, including climate change.

The Aging U.S. Bridge Infrastructure

As U.S. infrastructure ages, many bridges are approaching or exceeding their intended design life. Approximately 40% of U.S. bridges are over 50 years old, with around 54,560 classified as structurally deficient. While bridges have been inspected and maintained regularly, this study sheds light on a specific issue: malfunctioning expansion joints, small but critical components responsible for allowing bridge expansion and contraction during temperature changes.

Impact of Climate Change on Bridges

he study examines the effects of climate change on steel-span bridges, which were mass-produced during the highway boom of 1950s to 1970s, when the interstate highway system was being developed. These bridges, when subjected to higher future temperatures, are at risk of developing dangerous levels of thermal stress, especially when their expansion joints are clogged.

When debris builds up in these joints, it prevents the bridge from expanding as temperatures rise. This blockage causes axial pressure on the girders, which, combined with the weight of vehicles, could lead to structural fatigue, cracks, and even failure.

Researchers also studied how temperature changes during bridge construction impact their strength.
They looked at four scenarios: building bridges in winter, spring, summer, or fall. They found that:

If built in winter, 100% of bridges might be too weak.
If built in spring, 97% might be too weak.
If built in summer, 83% might be too weak.
If built in fall, 95% might be too weak.

Most Vulnerable Regions

The study identifies bridges in the Northern Rockies, Upper Midwest, and Northwest as the most vulnerable, particularly in states like North Dakota and South Dakota. These regions are likely to experience more severe temperature variations, exacerbating the effects of clogged joints and adding stress to already aging structures.

A Call for Action

With over 89,000 simply supported steel girder bridges analyzed, the study advocates for immediate attention to maintaining and clearing bridge expansion joints. It emphasizes that neglecting to address these climate-related challenges could lead to substantial economic and social costs. Prioritizing repair and maintenance will be essential to ensure the safety and longevity of U.S. infrastructure in the face of climate change.

Summing Up

This groundbreaking study, conducted by Susan Palu and Dr. Hussam Mahmoud at Colorado State University, offers critical insights into how climate change is accelerating the deterioration of U.S. bridges. Without intervention, the impact on national infrastructure could be catastrophic. Policymakers, engineers, and transportation authorities are urged to take immediate steps to mitigate these risks and protect public safety.

By staying ahead of these challenges, the U.S. can safeguard its infrastructure from the growing threat of climate change.

Source: Palu, S., & Mahmoud, H. (2019). Impact of climate change on the integrity of the superstructure of deteriorated U.S. bridges. PLOS ONE, 14(10), e0223307. https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0223307.