Executive summary

Current patterns of production and consumption have far-reaching consequences for global resources, greenhouse gas (GHG) emissions and waste generation. Each year, the world generates around 2.6 billion tonnes of municipal solid waste (MSW) – enough to cover New York City under ten metres of waste. The disposal, treatment and incineration of waste alone accounts for about 4% of global GHG emissions, including nearly 20% of global anthropogenic methane emissions, a greenhouse gas that is much more potent than carbon dioxide (CO2). The emissions footprint of waste and inefficient resource use is even greater when full value chains and production systems are taken into account. Tackling waste is thus a key opportunity to slow near-term global warming and contribute to global net zero goals.

Transitioning towards a zero waste economy requires rethinking how goods and infrastructure are designed, produced, consumed and treated at end-of-life. Doing so would mean that fewer resources are used, products last longer, materials are reused and recycled, and what was once waste is instead turned into a valuable resource wherever possible.

More strongly incorporating zero waste and circular economy objectives into the international climate agenda has strong potential to accelerate progress. The Türkiye COP31 Presidency has announced an ambitious goal to reduce the projected increase in global annual MSW generation by at least 50% by 2035 and to boost circular economy approaches. Achieving this goal requires businesses to redesign and innovate across the life cycle of products, buildings and infrastructure, and governments to rethink how policies can enable such a transformation.

Achieving the COP31 Presidency’s goals will require economy-wide action, including preventing food waste and encouraging more sustainable consumption; designing products and buildings that use materials more efficiently and avoid generating waste; expanding reuse and recycling; and improving waste collection and treatment systems.

There are considerable synergies between waste reduction, circularity and energy systems decarbonisation. This report identifies three key areas where GHG emissions reductions and improved resource efficiency outcomes can be achieved together: waste prevention and material efficiency; collection, sorting and recycling; and sustainable energy recovery from residual waste streams.

Implementing a comprehensive package of actions in these areas could cut global GHG emissions by more than 1.5 gigatonnes of carbon dioxide equivalent (Gt CO2-eq) annually by 2035, comparable to bringing the emissions from half the global car fleet to zero. Additionally, they would ease pressures on resources, improve health and local environmental outcomes, create new economic opportunities, generate additional jobs in value-added sectors, and enhance global energy security, including through the use of organic waste as fuel. Most of these measures can be achieved using proven technologies and practices. Priorities will vary by country depending on the national context, the maturity of existing waste management systems, institutional capacity and access to finance.

Five energy-intensive materials-based sectors – steel, cement, chemicals (including plastics), aluminium and paper – account for nearly 20% of global energy-related CO2 emissions today. Using these materials more efficiently in buildings, vehicles, packaging and other value chains can reduce energy use and emissions associated with their production while cutting waste at its source. Product and infrastructure design is a key leverage point, helping optimise material inputs while enabling longer lifetimes, repair, reuse and recycling. Opportunities also exist across value chains, from minimising losses during construction to expanding shared-use models. Illustrative examples include the Quay Quarter Tower in Sydney, Australia, where an existing building was redeveloped rather than demolished and rebuilt, retaining over 65% of its structural elements and avoiding about 7 300 tonnes of embodied CO2; and the city-wide REUSABLE system in Aarhus, Denmark, where the same takeaway cups are returned and reused across multiple participating businesses, reducing the need for single-use packaging. Actions in this area have the potential to reduce emissions by around 0.7 Gt CO2-eq annually by 2035.

Stronger end-of-life waste collection and sorting are essential to improving waste management, opening up opportunities to recover value from materials while reducing emissions. Maximising recycling potential can keep waste out of landfills and reduce demand for virgin materials and the energy needed to produce them. While large-volume metals like steel and aluminium already have relatively high recycling rates, further efforts are especially needed for plastics: through stronger collection and sorting and continued innovation on recycling methods, global plastics recycling could double by 2035. An illustrative example is Seoul, Korea, where households are required to collect transparent PET bottles separately from other plastics, enabling higher-quality recycling into new products such as clothing and bags. Stronger efforts in this area across all materials have the potential to reduce emissions by at least 0.4 Gt CO2-eq annually by 2035.

Even in a transition towards zero waste, some residual waste will remain difficult or uneconomic to recycle. Energy recovery from organic waste – while simultaneously maximising efforts to prevent organic waste where possible – can tackle two challenges at once: avoiding methane emissions from disposal and increasing the supply of low-emissions fuels and valuable by‑products. Global production of biogases – derived from feedstocks such as crop residues, manure and MSW – could quadruple by 2035. Emerging market and developing economies (EMDEs) account for more than half of the associated emissions reduction potential. Production of biogases can enhance energy security by using resources produced close to where they are consumed: the energy from quadrupling the production of biogases is equivalent to all the liquid natural gas exported via the Strait of Hormuz in 2025. The city of Indore in India illustrates how biomethane production can be integrated into waste management: its largest plant converts 550 tonnes of organic waste each day into biomethane, fuelling more than 400 city buses. Biogases production could be complemented by the use of organic waste as a solid fuel in power generation and parts of industry. Increased global action on sustainable energy recovery from waste has the potential to reduce emissions by at least 0.6 Gt CO2-eq annually by 2035.