Report on Methane Emissions from Landfills and Alignment with Sustainable Development Goals

Introduction: The Climate Impact of Solid Waste

Solid waste deposited in landfills represents the third-largest global source of anthropogenic methane, a potent greenhouse gas. The continuous emission of methane from these sites poses a significant challenge to achieving climate targets. This issue is central to SDG 13 (Climate Action), which calls for urgent measures to combat climate change and its impacts. Methane emissions from landfills are highly variable, influenced by factors such as local waste management practices and climatic conditions, making accurate assessment and mitigation critical.

Assessment of Global Landfill Emissions

A comprehensive assessment was conducted on 102 high-emitting landfills worldwide using five years of satellite observation data. The study analyzed emissions under diverse management strategies and climate scenarios to understand the key drivers of methane release.

Key Findings and Discrepancies with Existing Inventories

• Underestimation of Emissions: The study reveals that for the observed sites, methane emissions from open dumps are underestimated by a factor of 5.3 ± 0.3 in the EDGAR v8.0 inventory. This significant discrepancy highlights a critical data gap that hinders effective climate action.
• Impact on Urban Sustainability (SDG 11): Inaccurate emission data directly affects the ability of nations to meet SDG 11 (Sustainable Cities and Communities), specifically Target 11.6, which aims to reduce the adverse per capita environmental impact of cities, including through improved waste management.

Mitigation Strategies and Contribution to Sustainable Development Goals

A targeted approach to waste management can drastically reduce methane emissions and advance several SDGs simultaneously. The recommended strategy involves a two-pronged approach:

1. Upgrading Waste Infrastructure: Transforming open dumpsites worldwide into modern sanitary landfills. This directly supports SDG 11 by creating safer and more environmentally sound urban infrastructure.
2. Promoting a Circular Economy: Diverting organic waste from landfills to composters and biodigesters. This measure is fundamental to SDG 12 (Responsible Consumption and Production), particularly Target 12.5, which focuses on substantially reducing waste generation. Furthermore, capturing methane in biodigesters can contribute to SDG 7 (Affordable and Clean Energy).

Quantified Mitigation Potential for Climate Action (SDG 13)

The implementation of these improved waste management practices offers substantial climate benefits:

• A potential global reduction in methane emissions from the solid waste sector by 80% (with a confidence interval of 60–89%).
• An annual mitigation potential equivalent to 760 megatonnes of CO₂ (Mt CO₂e), with an estimated range of 570–850 Mt CO₂e.

Achieving this reduction represents a highly effective and actionable strategy for fulfilling commitments under SDG 13.

Conclusion and Recommendations for Global Partnership (SDG 17)

The findings confirm that prioritizing improved solid waste management is one of the most impactful strategies for mitigating methane emissions. A critical recommendation is to focus efforts on developing countries, where the prevalence of open dumpsites is highest. This underscores the importance of SDG 17 (Partnerships for the Goals), as success depends on robust international cooperation, including the provision of economic and technological support to facilitate the transition to sustainable waste management systems. Such partnerships are essential to unlock the full mitigation potential and advance a sustainable, low-carbon future for all.

Analysis of Sustainable Development Goals in the Article

1. Which SDGs are addressed or connected to the issues highlighted in the article?

SDG 11: Sustainable Cities and Communities

• The article’s core subject is the management of solid waste in landfills, which is a critical component of urban infrastructure and environmental management. It directly addresses the environmental impact of cities by focusing on emissions from municipal waste.

SDG 12: Responsible Consumption and Production

• The article discusses waste management practices and proposes solutions like diverting organic waste. This relates to Target 12.5, which aims to substantially reduce waste generation through reduction and recycling, thereby promoting sustainable production and consumption patterns.

SDG 13: Climate Action

• The central theme is the significant emission of methane, a potent greenhouse gas, from landfills. The article quantifies these emissions and proposes mitigation strategies, directly contributing to the global effort to combat climate change and its impacts.

SDG 17: Partnerships for the Goals

• The article explicitly mentions the need to support developing countries with “economic and technological measures” to improve their waste management systems. This highlights the importance of international cooperation, technology transfer, and financial assistance to achieve global environmental goals.

2. What specific targets under those SDGs can be identified based on the article’s content?

1. SDG 11: Sustainable Cities and Communities

   • Target 11.6: By 2030, reduce the adverse per capita environmental impact of cities, including by paying special attention to air quality and municipal and other waste management. The article’s entire focus on assessing and mitigating methane emissions from landfills is a direct effort to reduce the environmental impact of municipal waste. The proposal to transform “open dumpsites” into “sanitary landfills” directly addresses this target.

2. SDG 12: Responsible Consumption and Production

   • Target 12.5: By 2030, substantially reduce waste generation through prevention, reduction, recycling and reuse. The article’s proposed strategy to divert “organic waste to composters and biodigesters” is a form of waste reduction (at the landfill) and recycling, preventing it from generating methane.

3. SDG 13: Climate Action

   • Target 13.2: Integrate climate change measures into national policies, strategies and planning. The article presents improved waste management as “one of the most effective strategies for mitigating methane emissions from the solid waste sector,” advocating for its integration into climate action plans.

4. SDG 17: Partnerships for the Goals

   • Target 17.7: Promote the development, transfer, dissemination and diffusion of environmentally sound technologies to developing countries. The article concludes by stating that prioritizing improved waste management in developing countries must be “supported by economic and technological measures,” a direct call for the actions described in this target.

3. Are there any indicators mentioned or implied in the article that can be used to measure progress towards the identified targets?

1. For Target 11.6:

   • Type of waste management facility: The article differentiates between “open dumps” and “sanitary landfills,” which directly relates to Indicator 11.6.1 (Proportion of municipal solid waste collected and managed in controlled facilities). Progress can be measured by the rate of transformation from open dumps to sanitary landfills.
   • Methane emissions from landfills: The study uses “satellite observations” to assess methane emissions, providing a direct, quantifiable indicator of the environmental impact of waste.

2. For Target 12.5:

   • Amount of organic waste diverted: The recommendation to divert “organic waste to composters and biodigesters” implies an indicator measuring the tonnage or percentage of organic waste that is recycled rather than sent to landfills. This aligns with Indicator 12.5.1 (National recycling rate).

3. For Target 13.2:

   • Reduction in greenhouse gas emissions: The article provides a clear, quantifiable indicator of progress. It states that improved management can “decrease methane emissions by 80% (60–89%),” offering a “mitigation potential of 760 (570–850) Mt CO₂e annually.” This directly measures progress toward reducing total greenhouse gas emissions (Indicator 13.2.2).

4. For Target 17.7:

   • Provision of support to developing countries: The article implies a qualitative indicator by highlighting the need for “economic and technological measures” to support developing countries. Progress could be measured by the amount of investment, technology transfer programs, and capacity-building initiatives directed toward waste management in these nations.

4. Table of SDGs, Targets, and Indicators

Source: nature.com