By Marc Tijhuis, Managing Director at ISWA International Solid Waste Association

The growing volume of waste and widespread mismanagement are among the most pressing sustainability and public health challenges worldwide. According to the International Solid Waste Association (ISWA), transforming waste and resource management systems offers one of the most impactful and underutilized strategies for mitigating climate change. This article examines how circular economy principles, the reduction of short-lived climate pollutants, and context-specific waste management interventions can meaningfully reduce greenhouse gas (GHG) emissions—while improving human and environmental health. 

The Waste Crisis and Its Carbon Impact  

Globally, more than 2.7 billion people lack access to basic waste collection services. In many regions, the result is the open dumping or burning of waste, both of which contribute to climate change and severe air quality impacts. These practices emit not only methane (CH₄) and carbon dioxide (CO₂), but also black carbon—a short-lived climate pollutant with a global warming potential many times greater than CO₂ over a 20-year period. Addressing open burning and unmanaged organic waste streams is critical for near-term climate mitigation and public health protection. 

Although the waste sector contributes an estimated 3–5% of global GHG emissions directly, its indirect mitigation potential—through avoided emissions in the materials, agriculture, and energy sectors—is much higher. Methane from landfills accounts for approximately 20% of global anthropogenic methane emissions, but other sources (notably fossil fuel production and agriculture) are also significant. Effective waste management strategies can therefore play a key role in reducing short-lived climate pollutants, especially in regions with high rates of open dumping and organic waste mismanagement. 

Circular Economy and Carbon Reduction Strategies 

A circular economy aims to minimize waste and keep materials in use for as long as possible, maximizing their value and reducing emissions associated with virgin material extraction and production. This vision requires a system-wide approach that goes beyond recycling and includes strategies such as reuse, refurbishing, and remanufacturing—all of which preserve embodied carbon more effectively than recycling or disposal. While not directly involved in these other strategies, the waste and resources sector can and should play a strong supporting role in enabling them. 

Key climate-relevant strategies include: 

1. Waste Prevention and Resource Optimization 

  • Prevention is the most effective climate strategy. It reduces the need for material extraction, processing, and transport—often the most carbon-intensive parts of the product lifecycle. 
  • Reusing and repairing products retain more value and carbon than recycling. These strategies are central to the circular economy and should be prioritized accordingly. 
  • For example, recycling aluminium saves up to 95% of the energy required to produce new aluminium from raw materials. 

2. Environmentally Sound Organic Waste Management 

  • Organic waste is the largest component of municipal solid waste globally and a major source of methane in unmanaged settings. 
  • Composting and anaerobic digestion can significantly reduce methane emissions if well-planned, implemented, and monitored.  
  • Example: Austria’s nutrient recycling model, where more than 45% of biosolids are used in agriculture, illustrates how circular organic waste systems can support climate, soil, and food security objectives. 

3. Energy Recovery Pathways 

  • Incineration with energy recovery can reduce reliance on landfilling for non-recyclable, contaminated, or hazardous wastes. However, it must not displace higher-order strategies like prevention, reuse, or recycling. 
  • Energy recovery is not the primary goal of incineration; rather, the focus should be on volume reduction, contaminant control, and appropriate management of residuals.  
  • ISWA recommends that WTER be approached as one component of a broader, technology-agnostic system aligned with the waste hierarchy. 

Policy, Equity, and Regional Contexts 

To ensure waste management supports climate objectives, interventions must be customized to local social, economic, and cultural realities. This includes: 

  • Universal access to collection and safe disposal as a foundational goal, especially in the Global South. 
  • Integration of waste strategies into Nationally Determined Contributions (NDCs) under the Paris Agreement. 
  • Inclusive stakeholder engagement, particularly involving informal workers, who play a vital role in resource recovery in many regions. 
  • Leveraging climate finance (e.g., Green Climate Fund, carbon markets) to upgrade infrastructure and build local capacity. 

As ISWA has emphasized in its Declaration on Climate Change, modern waste management should be recognized as a key enabler of climate resilience, low-emissions development, and just transitions—especially in underserved communities. 

Conclusion 

Sustainable waste management is not only about treating waste—it is about rethinking systems to minimize resource loss, maximize value retention, and reduce emissions. By aligning local interventions with circular economy principles and climate goals, countries can significantly cut short-lived climate pollutants, improve livelihoods, and safeguard public health. 

Rather than being viewed as a burden, the waste sector should be recognized as a climate solution—a catalyst for more resilient, inclusive, and sustainable societies.