Roland Geyer

Bio: Roland Geyer is an academic researcher from University of California, Santa Barbara. The author has contributed to research in topics: Reuse & Life-cycle assessment. The author has an hindex of 27, co-authored 71 publications receiving 14595 citations. Previous affiliations of Roland Geyer include University of California.

Production, use, and fate of all plastics ever made

Abstract: Plastics have outgrown most man-made materials and have long been under environmental scrutiny. However, robust global information, particularly about their end-of-life fate, is lacking. By identifying and synthesizing dispersed data on production, use, and end-of-life management of polymer resins, synthetic fibers, and additives, we present the first global analysis of all mass-produced plastics ever manufactured. We estimate that 8300 million metric tons (Mt) as of virgin plastics have been produced to date. As of 2015, approximately 6300 Mt of plastic waste had been generated, around 9% of which had been recycled, 12% was incinerated, and 79% was accumulated in landfills or the natural environment. If current production and waste management trends continue, roughly 12,000 Mt of plastic waste will be in landfills or in the natural environment by 2050.

Plastic waste inputs from land into the ocean

Abstract: Plastic debris in the marine environment is widely documented, but the quantity of plastic entering the ocean from waste generated on land is unknown. By linking worldwide data on solid waste, population density, and economic status, we estimated the mass of land-based plastic waste entering the ocean. We calculate that 275 million metric tons (MT) of plastic waste was generated in 192 coastal countries in 2010, with 4.8 to 12.7 million MT entering the ocean. Population size and the quality of waste management systems largely determine which countries contribute the greatest mass of uncaptured waste available to become plastic marine debris. Without waste management infrastructure improvements, the cumulative quantity of plastic waste available to enter the ocean from land is predicted to increase by an order of magnitude by 2025.

Circular economy rebound

Abstract: Summary The so-called circular economy—the concept of closing material loops to preserve products, parts, and materials in the industrial system and extract their maximum utility—has recently started gaining momentum. The idea of substituting lower-impact secondary production for environmentally intensive primary production gives the circular economy a strong intuitive environmental appeal. However, proponents of the circular economy have tended to look at the world purely as an engineering system and have overlooked the economic part of the circular economy. Recent research has started to question the core of the circular economy—namely, whether closing material and product loops does, in fact, prevent primary production. In this article, we argue that circular economy activities can increase overall production, which can partially or fully offset their benefits. Because there is a strong parallel in this respect to energy efficiency rebound, we have termed this effect “circular economy rebound.” Circular economy rebound occurs when circular economy activities, which have lower per-unit-production impacts, also cause increased levels of production, reducing their benefit. We describe the mechanisms that cause circular economy rebound, which include the limited ability of secondary products to substitute for primary products, and price effects. We then offer some potential strategies for avoiding circular economy rebound. However, these strategies are unlikely to be attractive to for-profit firms, so we caution that simply encouraging private firms to find profitable opportunities in the circular economy is likely to cause rebound and lower or eliminate the potential environmental benefits.

The Economics of Remanufacturing Under Limited Component Durability and Finite Product Life Cycles

Abstract: This paper models and quantifies the cost-savings potential of production systems that collect, remanufacture, and remarket end-of-use products as perfect substitutes while facing the fundamental supply-loop constraints of limited component durability and finite product life cycles. The results demonstrate the need to carefully coordinate production cost structure, collection rate, product life cycle, and component durability to create or maximize production cost savings from remanufacturing.

Production, use, and fate of all plastics ever made

Abstract: Plastics have outgrown most man-made materials and have long been under environmental scrutiny. However, robust global information, particularly about their end-of-life fate, is lacking. By identifying and synthesizing dispersed data on production, use, and end-of-life management of polymer resins, synthetic fibers, and additives, we present the first global analysis of all mass-produced plastics ever manufactured. We estimate that 8300 million metric tons (Mt) as of virgin plastics have been produced to date. As of 2015, approximately 6300 Mt of plastic waste had been generated, around 9% of which had been recycled, 12% was incinerated, and 79% was accumulated in landfills or the natural environment. If current production and waste management trends continue, roughly 12,000 Mt of plastic waste will be in landfills or in the natural environment by 2050.

River plastic emissions to the world's oceans.

Abstract: Plastics in the marine environment have become a major concern because of their persistence at sea, and adverse consequences to marine life and potentially human health. Implementing mitigation strategies requires an understanding and quantification of marine plastic sources, taking spatial and temporal variability into account. Here we present a global model of plastic inputs from rivers into oceans based on waste management, population density and hydrological information. Our model is calibrated against measurements available in the literature. We estimate that between 1.15 and 2.41 million tonnes of plastic waste currently enters the ocean every year from rivers, with over 74% of emissions occurring between May and October. The top 20 polluting rivers, mostly located in Asia, account for 67% of the global total. The findings of this study provide baseline data for ocean plastic mass balance exercises, and assist in prioritizing future plastic debris monitoring and mitigation strategies. Rivers provide a major pathway for ocean plastic waste, but effective mitigation is dependent on a quantification of active sources. Here, the authors present a global model of riverine plastic inputs, and estimate annual plastic waste of almost 2.5 million tonnes, with 86% sourced from Asia.

Progress and Perspectives of Electrochemical CO2 Reduction on Copper in Aqueous Electrolyte

Abstract: To date, copper is the only heterogeneous catalyst that has shown a propensity to produce valuable hydrocarbons and alcohols, such as ethylene and ethanol, from electrochemical CO2 reduction (CO2R). There are variety of factors that impact CO2R activity and selectivity, including the catalyst surface structure, morphology, composition, the choice of electrolyte ions and pH, and the electrochemical cell design. Many of these factors are often intertwined, which can complicate catalyst discovery and design efforts. Here we take a broad and historical view of these different aspects and their complex interplay in CO2R catalysis on Cu, with the purpose of providing new insights, critical evaluations, and guidance to the field with regard to research directions and best practices. First, we describe the various experimental probes and complementary theoretical methods that have been used to discern the mechanisms by which products are formed, and next we present our current understanding of the complex reaction networks for CO2R on Cu. We then analyze two key methods that have been used in attempts to alter the activity and selectivity of Cu: nanostructuring and the formation of bimetallic electrodes. Finally, we offer some perspectives on the future outlook for electrochemical CO2R.

What a Waste 2.0: A Global Snapshot of Solid Waste Management to 2050

Abstract: By 2050, the world is expected to generate 340 billion tons of waste annually, increasing drastically from today’s 201 billion tons What a Waste 20: A Global Snapshot of Solid Waste Management to 2050 aggregates extensive solid waste data at the national and urban levels It estimates and projects waste generation to 2030 and 2050 Beyond the core data metrics from waste generation to disposal, the report provides information on waste management costs, revenues, and tariffs; special wastes; regulations; public communication; administrative and operational models; and the informal sector