More Like this

1. Life cycle based alternatives assessment (LCAA) for chemical substitution

   https://doi.org/10.1039/d0gc01544j  

   Fantke, Peter; Huang, Lei; Overcash, Michael; Griffing, Evan; Jolliet, Olivier (September 2020, Green Chemistry)

   null (Ed.)

   The world faces an increasing need to phase out harmful chemicals and design sustainable alternatives across various consumer products and industrial applications. Alternatives assessment is an emerging field with focus on identifying viable solutions to substitute harmful chemicals. However, current methods fail to consider trade-offs from human and ecosystem exposures, and from impacts associated with chemical supply chains and product life cycles. To close this gap, we propose a life cycle based alternatives assessment (LCAA) framework for consistently integrating quantitative exposure and life cycle impact performance in the substitution process. We start with a pre-screening based on function-related decision rules, followed by three progressive tiers from (1) rapid risk screening of various alternatives for the consumer use stage, to (2) an assessment of chemical supply chain impacts for selected alternatives with substantially different synthesis routes, and (3) an assessment of product life cycle impacts for alternatives with substantially different product life cycles. Each tier focuses on relevant impacts and uses streamlined assessment methods. While the initial risk screening will be sufficient for evaluating chemicals with similar supply chains, each additional tier helps further restricting the number of viable solutions, while avoiding unacceptable trade-offs. We test our LCAA framework in a proof-of-concept case study for identifying suitable alternatives to a harmful plasticizer in household flooring. Results show that the use stage dominates human health impacts across alternatives, supporting that a rapid risk screening is sufficient unless very different supply chains or a broader set of alternative materials or technologies are considered. Combined with currently used indicators for technical and economic performance, our LCAA framework is suitable for informing function-based substitution at the level of chemicals, materials and product applications to foster green and sustainable chemistry solutions. 

   more » « less
2. Post-NAFTA Changes in Peasant Land Use—The Case of the Pátzcuaro Lake Watershed Region in the Central-West México

   https://doi.org/10.3390/land9030075  

   Astier, Marta; Orozco-Ramírez, Quetzalcóatl; Walker, Robert; Galván-Miyoshi, Yankuic; González-Esquivel, Carlos; Simmons, Cynthia S. (March 2020, Land)

   null (Ed.)

   Rural life in México has changed drastically over the past several decades in the wake of structural reforms in the 1980s and the North American Free Trade Agreement (NAFTA) implemented in 1994. Researchers predicted dire consequences for smallholder farmers following trade liberalization and in certain respects the prophecies have been fulfilled. Indeed, many regions experienced significant out-migration as smallholders, unable to compete with global maize imports without price subsidies, sold or abandoned their lands, making way for the expansion of industrial agriculture into forests, secondary vegetation and primary crops. Nevertheless, many smallholders have adapted to the new economic environment with farming systems that manage risk by diversifying portfolios to incorporate commercialized maize and livestock production. This article examines the evolution of smallholder farming systems since the mid 1980s, when the impact of neoliberal reforms emerged, using data collected from field research on 130 smallholder farms in the Pátzcuaro Lake Watershed (PLW) in the State of Michoacán. Farmers in the PLW have been characterized as traditional peasant farmers, planting crops for subsistence, including a diverse array of domestic maize varieties and practicing limited animal husbandry with chickens, turkeys, pigs, an oxen and a cow or two for milk. But the results presented in this article show that the traditional peasant farming systems in the region have changed substantially to a highly diversified agriculture-cattle-forest system. Most notable changes include the use of fertilizers and pesticides; and the increase in livestock herd and reorientation to beef production. The results demonstrate the resilience of smallholder farmers, while at the same time raising potential concern that increased reliance on livestock and beef production specialization, might lead to shifts in farming systems that replace domestic maize varieties with hybrid corn used primarily for animal feed and thereby leaving vulnerable the genetic reservoir of traditional maize landraces. 

   more » « less
3. Environmental impacts of circularity strategies for social distancing plastic shields made of polymethyl methacrylate in the United States

   https://doi.org/10.1177/0734242X241237102  

   Silva_de_Souza_Lima_Cano, Nathalia; Hossain, Md Uzzal; Bilec, Melissa M (April 2024, Waste Management & Research: The Journal for a Sustainable Circular Economy)

   One application of plastics that grew during the COVID-19 pandemic is for social distancing plastic shields, or protective barriers, made from polymethyl methacrylate (PMMA) such as transparent face guards. Although available for other applications, end-of-life impacts for barriers are currently lacking in the literature, and there is a need to fill in this gap to guide decisions. This study evaluated the end-of-life environmental impacts of PMMA barriers in the United States by using life cycle assessment. We evaluated five strategies including landfilling, waste-to-energy, mechanical recycling, chemical recycling and reuse. Data were sourced from literature and various life cycle inventory databases. The Tool for Reduction and Assessment of Chemicals and Other Environmental Impacts (TRACI) was used as the life cycle impact assessment method. Landfilling exhibited the highest impact in all indicators and reuse demonstrated optimal results for global warming potential. A scenario analysis was conducted to explore a combination of strategies, revealing that the most promising approach involved a mix of 40% reuse, 20% mechanical recycling and 40% chemical recycling. Circular economy recommendations are proposed for managing these sources of plastic waste in the United States. 

   more » « less
4. An agent-based model of agricultural land use in support of local food systems

   https://doi.org/10.1109/WSC60868.2023.10408152  

   Patel, P; Krejci, C; Schwab, N; Dorneich, M (December 2023, Proceedings of the Winter Simulation Conference)

   Local food systems, in which consumers source food from nearby farmers, offer a sustainable alternative to the modern industrial food supply system. However, scaling up local food production to meet consumer demand will require farmers to allocate more land to this purpose. This paper describes an agent-based model that represents commodity-producing Iowa farmers and their decisions about converting some of their acreage to specialty crop production for local consumption. Farmer agents’ land-use decisions are informed by messages passed to them via their social connections with other farmers in their communities and messages from agricultural extension agents. Preliminary experimentation revealed that leveraging extension agents to increase the frequency and strength of messages to farmers in support of local food production has a modest positive impact on adoption. By itself, however, this intervention is unlikely to yield significant improvements to food system sustainability. 

   more » « less
5. TOWARDS FOOD SOVEREIGNTY: THE ROLE OF SMALLHOLDER FARMERS’ SEED SECURITY IN IMPROVING CLIMATE CHANGE RESILIENCE IN NORTHERN MALAWI

   https://doi.org/10.1080/00167428.2024.2335395  

   Amoak, Daniel; Lupafya, Esther; Dakishoni, Laifolo; Luginaah, Isaac (April 2024, Geographical Review)

   With climate extreme events increasing in frequency and intensity in Malawi, the future of local food production faces serious threats, necessitating renewed efforts to build the adaptive capabilities of the majority poor smallholder farmers. In this context, seed security is critical to improving rural livelihoods and agrobiodiversity; however, knowledge of its role in climate change resilience is sparse. Drawing insights from vulnerability and resilience literature, this paper examines the role of seed security in enhancing climate change resilience in northern Malawi. Using a cross-sectional survey of 1,090 smallholder farmers and applying logistic regression analysis, the study found that households that are seed-secure were significantly more likely to report stronger resilience to climate change than those that were not seed-secure, even after controlling for theoretically relevant variables (OR = 1.89; p < .01). Other noteworthy predictors of climate change resilience included level of education, wealth, agroecological practice, and seed sources. Based on the findings, we advocate for promoting seed security as part of broader localized and place-specific action plans to foster resilience to climate change in agricultural regions. 

   more » « less