Current Waste Management Increases Global Warming

Have you ever wondered where the trash you throw away every day goes? Does it go to a landfill? Is it burned? Or is it recycled? Municipal solid waste, more simply called trash, is the unwanted material that we discard every day, whether it comes from homes, schools, or restaurants. Municipal solid waste can consist of food, plastics, paper, glass, and electronics, among other kinds of waste.

Our planet is facing a huge challenge in managing municipal solid waste. According to the World Bank, the world generates over 2 billion tons of solid waste annually (equivalent to the weight of 400 million elephants!), and this amount is expected to almost double by 2050 [1]. Much of this increase will come from rapidly developing countries where people are making more trash, but municipal solid waste management systems have not kept pace. This staggering amount of trash does not simply disappear when we throw it away. In many places, it ends up in open landfills, where it pollutes groundwater and rivers, spreads disease, and releases greenhouse gases that contribute to global warming (see Figure 1).

A major greenhouse gas released from open landfills is methane, which primarily comes from the breakdown of organic waste, such as food waste. Methane, a short-lived greenhouse gas, is 84 times more effective than carbon dioxide at trapping heat over a 20-year period. To reduce the continued warming caused by greenhouse gases, several global climate goals have been established. These include the Paris Agreement’s Goal, which aims to limit global temperature rise compared to the 1850–1900 period, as well as the Global Methane Pledge, which seeks a 30% reduction in methane emissions by 2030, based on a 2020 baseline.

Municipal Solid Waste Solutions to Reduce Global Warming

My team conducted a study to understand how global municipal solid waste management contributes to the warming of our planet [2]. We wanted to answer two big questions. First, can current municipal solid waste management practices effectively achieve climate goals? Second, if not, what are the possible solutions to help the world meet its climate goals? These questions are crucial because the way we handle our municipal solid waste today will affect the planet’s future. In this study, we included data from 43 countries and regions that produce 86% of the world’s municipal solid waste, using an artificial intelligence model to look at thousands of pieces of data from different countries to predict how fast Earth is warming.

We found some alarming results. If we continue with current practices for managing our municipal solid waste (meaning if we change nothing), emissions will exceed safe climate limits as early as 2027–2028 for the 1.5°C warming target and by 2038–2043 for the 2°C warming target. The situation is particularly critical in lower-income countries, where most municipal solid waste is organic and often disposed of improperly, such as in open landfills.

Because current practices cannot meet climate goals, we proposed four solutions: (1) Changing open landfills to managed landfills by capturing the landfill gas (which consists of 40%-60% methane by volume); (2) composting organic waste to make biofertilizers; (3) Sending organic waste to anaerobic digestion plants to generate biogas for heat and electricity; and (4) Cutting municipal solid waste generation in half.

One key discovery was that organic waste presents a big opportunity. Sending organic waste to composting plants and anaerobic digestion plants could reduce emissions by 59%-72%. We also found that different countries need different solutions. Developed countries, such as the United States and Japan, should focus on reducing waste, given their high rates of non-organic waste (e.g., plastics and packaging). For developing countries, composting and anaerobic digestion plants are necessary alternatives to open landfills, given the higher volumes of organic waste produced in these places.

Since municipal solid waste consists of different types of waste, there is no single solution that works on its own (see Figure 2). To reduce waste and emissions, governments should create a combined municipal solid waste management system with multiple strategies. Importantly, our study highlights that there is limited time left to make these changes. To meet climate goals, our proposed solutions must start quickly. Waste disposal and treatment facilities already exist, but they must take urgent action to implement these planet-saving methods.

Challenges for Sustainable Municipal Solid Waste Management

Despite our promising solutions, significant obstacles remain in the path to sustainable municipal waste management. Many countries lack the necessary infrastructure and laws to implement advanced municipal solid waste management systems. In many developing countries, open landfills remain the main method of disposal due to limited resources and the rapid growth of cities [3]. Even in wealthy nations, unclear rules and weak penalties weaken municipal solid waste reduction and recycling efforts.

Economic barriers also slow progress. Building new solid waste infrastructures requires major investments that many countries cannot afford. However, some countries are coming up with creative ways to pay for these upgrades. In Indonesia, a program called Waste Banks allows community members to deposit recyclables in exchange for cash. Norway’s deposit return system for cans and plastic bottles achieves a 92.3% return rate, demonstrating that well-designed money-based rewards can significantly improve recycling rates and promote good habits among consumers.

Changing human behavior may be the most challenging task of all. After years of getting used to throwing things away, many people do not want to take the extra time to sort their trash and make less waste. Japan has developed an outstanding recycling culture through extensive education starting in childhood, combined with strict rules and social pressure to follow them. Similar systems in other countries often fail because they do not have the same strong cultural foundation. Therefore, the government, companies, and parents should work to make sure everyone has good habits and encourage them to use less, waste less, and throw things away more carefully.

Companies also have an important responsibility. Many products are designed without considering their end-of-life disposal, making them difficult or impossible to recycle and reuse. Companies need to transition their businesses from a linear “throw-it-away” economy to a circular “use-it-again” economy, in which materials are continuously reused. The vision of a circular economy where nothing is wasted is within our reach if we act decisively. Every piece of municipal solid waste represents a misplaced resource or energy source that took water, raw materials, and fossil fuels to produce; throwing it away is essentially burying our planet’s limited resources.

Shaping a Sustainable Future for Municipal Solid Waste

We can all contribute to shaping a sustainable future through daily choices: carrying reusable containers, repairing rather than replacing items, and properly sorting recyclables. Communities can improve how they handle their trash, such as by creating deposit systems and encouraging people to sort food waste at home for composting and anaerobic digestion plants. Businesses can redesign products so that they last longer and are recyclable. Governments can invest in modern solid waste infrastructure and enforce responsible disposal practices. Students can advocate for better recycling programs at their schools. Perhaps most importantly, we all need to help instill good consumption and disposal patterns in today’s generations and the next.

Our study offers hope for the future. If we start treating municipal solid waste as a resource rather than trash, we could achieve net-zero waste emissions by 2050. We have created systems that generate too much waste and dispose of it poorly. Now we must design better management systems that value resources rather than waste them. With science, technology, and collective action, we can turn today’s trash into tomorrow’s treasure and build a resilient, sustainable future. The time to act is now. Our planet’s future depends on what we are willing to throw away today.

Glossary

Municipal Solid Waste: ↑ Solid waste generated by people in their daily lives or activities; more commonly known as trash or garbage, which comes from homes, schools, hospitals, and businesses.

Greenhouse Gases: ↑ Gases that trap heat in the atmosphere. Common greenhouse gases include carbon dioxide (CO₂), methane (CH₄), nitrous oxide (N₂O), and fluorinated gases.

Organic Waste: ↑ Biodegradable material, like fruit peels, leaves, eggshells, leftover food, or leaves/grass, which can be broken down by microorganisms into carbon dioxide, methane, or simple organic molecules.

Composting: ↑ Breakdown of organic materials by microorganisms, in the presence of oxygen, to create biofertilizers that improve soil health and fertility.

Biofertilizers: ↑ Materials that work with plant roots to turn nutrients in the soil into food that plants can easily eat and grow well.

Anaerobic Digestion: ↑ A process through which bacteria break down organic materials, such as food waste, human and animal manure, and wastewater biosolids to biogas in the absence of oxygen.

Biogas: ↑ A type of gas (mostly methane) produced from organic matter, which can be burned to cook food or make electricity.

Circular Economy: ↑ A way of making and using things that aims to prevent waste by reusing, repairing, and recycling materials, while also helping protect natural resources and ecosystems.

Conflict of Interest

The author(s) declared that this work was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.

Acknowledgments

The author would like to thank the co-authors (Hoy Zhen Xuan, Chin Wen Cheong, Fan Yee Van, and Yoo Seung Jick) of the original manuscript.

AI Tool Statement

The author(s) declared that Generative AI was not used in the creation of this manuscript.

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