“Gómez-Sanabria et al. (2022) argue that municipalities can integrate climate change adaptation and mitigation strategies into waste management practices through landfill diversion, recycling, composting, and circular-economy approaches to reduce greenhouse gas emissions and strengthen climate resilience.”

The IPCC states that waste management measures such as landfill methane capture, composting, anaerobic digestion, recycling and waste prevention can contribute to emissions reductions. This is relevant background because the claim attributes a climate-mitigation role to landfill diversion and circular-economy approaches, which is consistent with IPCC mitigation pathways, although the chapter does not specifically frame these measures as adaptation tools.

Waste and circular economy actions contribute to reducing the need for new primary materials and the associated greenhouse gas emissions linked to the extraction and processing of resources. Including circular economy and waste activities in the reporting on climate change mitigation policies and measures can help provide a fuller account of a country’s mitigation efforts. This approach can further reveal policy opportunities to unlock additional emission reductions and help countries reach their net-zero targets.

Better waste and resource management can make a significant contribution to climate mitigation, and must form a core part of every country's nationally determined contribution. Moving early to divert waste from landfill by separation at source and collecting clean organic and dry recycling fractions, will mitigate global GHG emissions, slash ocean plastics and create decent livelihoods. This multifaceted approach tackles all four quadrants in Figure 1, making it a comprehensive strategy to combat the global waste emergency and move towards a more sustainable future.

Gómez-Sanabria et al. write: "Our scenarios explore how improved waste collection, recycling of dry materials, separate collection and treatment of organic waste through composting and anaerobic digestion, and improved sanitary landfilling could reduce emissions." They find that, compared to the baseline, "the High Circularity scenario reduces cumulative GHG emissions from the MSW sector by up to 1.8 Gt CO2-eq over 2020–2050." The paper stresses that these measures are "consistent with circular economy strategies" and that in cities, "diversion of organic waste from landfills and increased recycling can support climate mitigation while improving local environmental conditions and resilience."

The IPCC assesses that waste management mitigation options include source separation, recycling, composting, landfill gas capture, and landfill diversion. These measures reduce methane and other greenhouse gas emissions by preventing organic waste from decomposing anaerobically in landfills and by displacing virgin-material production through circular-economy practices.

The report discusses circular economy actions, including waste prevention, separate collection, recycling, composting and energy recovery, as measures that can reduce greenhouse-gas emissions. It also notes that avoided emissions from lower landfill use are often calculated for separate collection of biogenic waste, indicating a direct mitigation pathway through waste diversion and circular waste management.

In the abstract, the authors explain that they ‘explore the potential global reductions of greenhouse gas (GHG) and air pollutant emissions from the implementation of circular municipal solid waste (MSW) management systems’ and that such systems ‘include restrained landfilling, increased material recycling, composting of biowaste, and energy recovery’. They conclude that ‘circular MSW management can deliver significant GHG and air pollutant emission reductions’ and highlight implications for climate‑change mitigation policies. The chapter does not explicitly discuss adaptation strategies or climate resilience of municipalities; its emphasis is on mitigation via technical waste‑management measures.

In its discussion of mitigation options, the IPCC cites Gómez‑Sanabria et al. (2022) as an example of studies showing ‘substantial mitigation potential from circular municipal solid waste management systems, including reduced landfilling, increased recycling and composting, and waste‑to‑energy.’ The chapter notes that such options can contribute significantly to reducing GHG emissions from the waste sector. However, the IPCC treats these as mitigation measures; adaptation and resilience aspects of municipal waste management are discussed separately and Gómez‑Sanabria et al. (2022) is not referenced in that context.

In the project summary, the authors explain that their work "quantifies current and future emissions of methane and air pollutants from municipal solid waste (MSW) management and the potential for emission reductions through improved MSW collection, recycling, composting, anaerobic digestion, and better landfilling practices." The description notes that the scenarios "are consistent with a shift towards a circular economy, emphasizing waste prevention, material recovery and diversion of organics from landfills" and that these strategies "can be implemented by municipalities to support climate change mitigation and adaptation goals."

This supplementary material for Gómez-Sanabria et al. (2022) presents scenario data for circular municipal waste management systems and their impacts on greenhouse gases and air pollutants. It is directly tied to the study cited in the claim and supports the paper’s focus on waste-system interventions such as recycling-oriented and circular approaches.

The methods section defines ‘circular MSW management systems’ as those ‘including restrained landfilling of MSW, increased material recycling rates, technological improvement, and implementation of separate collection and composting of biogenic waste.’ The study quantifies GHG and air pollutant emission reductions from these measures under global scenarios up to 2050. While the paper repeatedly frames MSW measures as ‘climate‑change mitigation options’, it does not frame them as climate‑change adaptation measures nor does it analyze impacts on municipal climate resilience such as flood risk reduction or heat‑stress management.

According to the PubMed abstract, the authors ‘evaluate the global mitigation potential of circular municipal solid waste (MSW) management systems’ and find that ‘by 2050, circular MSW management could reduce global GHG emissions from the waste sector by 84% compared to a no‑policy baseline.’ The abstract lists key interventions such as ‘diverting waste from landfills, improving recycling and composting, and recovering energy from waste’ and emphasizes their role in climate mitigation and air pollution control. The abstract does not mention climate adaptation, resilience, or integration of adaptation and mitigation strategies in municipal planning.

In this 2024 Nature Communications paper, Gómez‑Sanabria and Lindl ‘combine spatial analysis with the Shared Socioeconomic Pathways to project future waste leakage under current conditions and develop mitigation strategies up to 2040.’ They state that ‘we show the need for the adoption of active mitigation strategies, in particular circular waste management systems, that could stop waste from entering the aquatic ecosystems in the first place.’ The focus is on preventing waste leakage to aquatic environments and on meeting waste‑related Sustainable Development Goals; it does not argue that municipalities can integrate climate‑change adaptation and mitigation into waste management practices, nor does it analyze climate resilience.

The chapter explains that ‘the WROSE model/decision-making tool is a multiple scenario optimization model that analyzes and evaluates the feasibility of waste management strategies upon all four levels of sustainability (environmental, economic, social and institutional).’ It notes that ‘the need for improved waste management systems has gained momentum globally in order to work towards the reduction of GHG emissions and the impact it has on global climate change’ and that integrated waste management, including ‘separated collection at the source, decentralized recycling facilities, and sustainable end-of-life disposal options,’ can assist municipalities in ‘achieving zero waste’ and climate stabilisation. The focus is on mitigation of greenhouse gas emissions through waste‑hierarchy and circular‑economy approaches; explicit treatment of climate adaptation or resilience is limited and not framed as a central argument.

This review states that solid waste management is a cross-cutting issue that significantly influences multiple aspects of sustainable development globally. It reports that implementing circular-economy approaches in the waste sector has the potential to achieve net zero emissions from the global municipal solid waste management sector by 2030 and 2050, and that upgrading open dumps and standardising household-level waste separation are priority policies.

The 2022 Gómez-Sanabria et al. paper is widely cited for modeling how circular waste management measures—especially recycling, composting, anaerobic digestion, and landfill gas recovery—can reduce global greenhouse-gas emissions and air pollutants. However, the paper is primarily a mitigation study; it does not centrally argue that municipalities can strengthen climate resilience through adaptation planning, so the resilience/adaptation part of the claim is only indirectly supported.