Waste to Energy : A blind spot in global methane policy? The waste sector's WtE debate

When the United Nations published its Global Methane Status Report (GMSR) 2025, it was broadly seen as a step forward in the international effort to curb one of the most potent greenhouse gases driving the climate crisis. For parts of the waste management industry, however, the report's reception has been more cautious.

The WtE+X Knowledge Alliance — a strategic partnership comprising CEWEP, ESWET and WtERT — has welcomed the report's ambition while raising the alarm over what it describes as a critical omission: the absence of any clear definition or recognition of Waste-to-Energy (WtE) as a necessary final treatment option for non-recyclable residual waste.

In a newly published position paper, the Alliance argues that this gap is not merely a technical oversight. Given the GMSR's status as a globally influential reference document, the Alliance warns that what goes unnamed in its pages risks being unfunded, unbuilt, and ultimately unused — precisely where, in its view, it is needed most.

The Alliance broadly praises the GMSR for prioritising upstream interventions: waste prevention, recycling, composting, and anaerobic digestion. These measures are rightly placed at the top of the waste hierarchy, the organisations acknowledge. Yet they contend that even the most advanced waste management systems produce a residual fraction — material that cannot be recycled or biologically treated — and it is here that they believe the report's analytical framework begins to show its limitations.

According to the Alliance, the GMSR refers to "energy recovery" without offering a technical definition or distinguishing between biological and thermal routes. The term "thermal pre-treatment" appears only peripherally, with no conceptual development, no environmental performance criteria, and no monitoring, reporting and verification (MRV) requirements attached to it.

For the industry bodies involved, this vagueness carries serious practical consequences. The GMSR shapes national climate plans, EU external climate policy, development finance criteria, and sustainable investment frameworks. The Alliance's position is clear: when a technology is not explicitly named, defined and qualified in such a document, it tends to be excluded from implementation and financing decisions.

To illustrate the stakes, the Alliance points to a striking global imbalance. Approximately 500 million tonnes of municipal solid waste are treated annually in WtE facilities worldwide. Yet more than one billion tonnes continue to be landfilled each year — a situation the Alliance describes as one of the largest remaining sources of waste-related greenhouse gas emissions.

Landfills generate methane as organic matter decomposes anaerobically — a process that is difficult to control and, in many parts of the world, entirely unmonitored. The Alliance argues that in regions where waste governance is weak, the realistic alternative to WtE is not a well-functioning recycling system, but uncontrolled dumping or poorly managed landfill sites.

With rapid urbanisation accelerating, particularly across the Global South, the Alliance warns that failing to articulate a clear role for controlled thermal treatment now risks embedding decades of unnecessary emissions into newly built systems.

Speaking on behalf of the WtE+X Knowledge Alliance, Dr Siegfried Scholz, President of the European Suppliers of Waste-to-Energy Technology (ESWET), was direct in his assessment: "We ask to recognise the role of Waste-to-Energy for treating non-recyclable waste while avoiding methane emissions from landfills."

Dr Scholz also pointed to the European regulatory model as a potential template for global policy. "Within the European Union, Waste-to-Energy is clearly regulated, limited, and conditional on best available techniques, strict emissions limits, and robust monitoring. Reflecting this experience in global methane policy would make the GMSR more applicable, more credible, and better aligned with the urgency of the climate challenge."

The Alliance also highlights what it sees as instructive evidence from European practice: countries with the highest recycling rates also maintain significant WtE capacity, which the Alliance interprets as evidence that thermal treatment and material recovery are complementary rather than competing pathways within the waste hierarchy.

The Alliance's concerns extend beyond industry advocacy. Academic voices associated with the coalition argue that the omission also raises questions about the scientific completeness of the report's approach to reducing emissions across the waste management chain.

Prof. Huang Qunxing, Executive President of the Global Waste-to-Energy Research and Technology Council (WtERT) and Vice-Dean of the College of Energy Engineering at Zhejiang University, stated: "From a scientific standpoint, any comprehensive methane mitigation strategy in the waste sector must address the full waste management chain, including the residual fraction that cannot be recycled or biologically treated. Decades of peer-reviewed research and operational data demonstrate that controlled thermal treatment of residual waste plays a critical role in avoiding methane formation from landfills, while ensuring energy recovery and material stabilisation. The omission of this pathway risks creating a gap between scientific evidence and policy implementation."

The WtE+X Knowledge Alliance has set out three concrete requests for the GMSR's authors: that Waste-to-Energy be explicitly recognised as a distinct technological category; that its complementary role alongside recycling and biological treatment be clearly defined; and that eligibility criteria be established, aligned with best available techniques, environmental safeguards, and MRV requirements.

The Alliance is at pains to frame these not as a push for incineration over recycling, but as a call for policy coherence — for a global reference document to reflect what the industry considers the full reality of waste management in a world still far from achieving zero residual waste. Whether the GMSR's authors will agree remains to be seen.