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Background Climate change presents an increasing challenge for food-nutrition security. Nutrition metrics calculated from quantitative food system projections can help focus policy actions. Objectives To estimate future chronic and hidden hunger disability-adjusted life years (DALYs)—due to protein-energy undernutrition and micronutrient deficiencies, respectively—using food systems projections to evaluate the potential impact of climate change and agricultural sector investment for adaptation. Methods We use a novel combination of a chronic and hidden hunger DALY estimation procedure and food system projections from quantitative foresight modeling to assess DALYs under alternative agricultural sector scenarios to midcentury. Results Total chronic and hidden hunger DALYs are projected to increase globally out to 2050—by over 30 million compared with 2010—even without climate change. Climate change increases total DALY change between 2010 and 2050 by nearly 10% compared with no climate change. Agricultural sector investments show promise for offsetting these impacts. With investments, DALY incidence due to chronic and hidden hunger is projected to decrease globally in 2050 by 0.24 and 0.56 per 1000 capita, respectively. Total global DALYs will still rise because projected population growth will outpace the rate reduction, especially in Africa south of the Sahara. However, projections also show important regional reductions in total DALYs due to chronic (13.9 million in South Asia, 4.3 million in East Asia and the Pacific) and hidden hunger (7.5 million in East Asia and the Pacific) with investments. Conclusions Food system projections to 2050 show a decreasing DALY incidence from both chronic and hidden hunger. Population growth is projected to outpace these improvements and lead to increasing total chronic and hidden hunger DALYs globally, concentrated in Africa south of the Sahara. Climate change increases per-capita chronic and hidden hunger DALY incidence compared with no climate change. Agricultural sector investments show the potential to offset the climate impact on DALYs. [ABSTRACT FROM AUTHOR]

Recycling is generally recognized as a key component of strategies to achieve improved resource efficiency and reduce the environmental burden associated with resource use. However, to maximize the net benefits offered by recycling, one must understand the system-wide effects of substituting primary materials with recycled materials and how those effects vary under alternative strategies. Consequential life cycle assessment (cLCA) approaches to evaluate the impact of increasing use of recycled materials require identification of grades and sources of scrap materials used at the margin. Various grades of recycled materials differ in their substitution possibilities and supply limits. However, most studies of cLCA for material recycling overlook these aspects and typically assume a fixed set of marginal activities. This study develops a model to describe the resource consumption behaviors of material producers and the resulting cascade of material flows for the case of the United States (US) pulp and paper industry. We observe that grades and sources of scrap materials used at the margin dynamically change so as the resulting environmental impact when demand for recycled containerboard products increases. The results show that the greenhouse gas (GHG) emission savings effect of using recycled materials can be considerably larger when marginal recovered fiber comes from additional recovery from landfill rather than being diverted from the export market. Also, the results show that the behavior of international trade partners for recovered paper may offset GHG emission savings from the domestic replacement of virgin pulpwood with recovered paper. Most importantly, such behaviors are dependent on grades used at the margin. The developed model and results can help inform the US pulp and paper industry, policymakers, and other stakeholders about the system-wide effects of increasing use of recovered paper. • We develop a model to describe resource consumption behaviors of the US pulp and paper producers and resulting fiber flows. • This study suggests the importance of identifying the grade and source of scrap used at the margin in the recycling industry. • CLCA based on static marginal technologies may not correctly quantify the system-wide effect of material recycling. [ABSTRACT FROM AUTHOR]

Abstract This paper performs a multi-model comparison to assess strategies for adaptation to climate change impacts in hydropower generation in Brazil under two Representative Concentration Pathways. The approach used allows for evaluating the interactions between climate change mitigation and adaptation strategies under low and high impact scenarios through 2050. Climate change impact projections of sixteen General Circulation Models indicate that a global high emissions trajectory scenario would likely yield more severe impacts on hydropower generation than a mitigation scenario. Adaptation modeling suggests that climate change impacts can be compensated by a wide range of alternatives, whose optimality will depend on the level of mitigation effort pursued. Our results show that climate change impacts would lead to even higher emissions in the absence of climate change mitigation policies. On the other hand, mitigation strategies to pursue lower emissions are maintained under climate change impacts, meaning that mitigation strategies are robust when faced with adaptation challenges. Mitigation efforts could yield a more diverse and less carbon intensive mix of technological options for adaptation. When analyzing investment costs to adapt to climate change impacts, in some cases mitigation can lead to a lower total investment level. Highlights • Climate change impacts on hydropower are assessed for sixteen models and two scenarios. • Interactions between climate change mitigation and adaptation are analyzed. • Adaptation/mitigation strategies from six different energy models are compared. • Adaptation and mitigation investment costs are assessed and compared. [ABSTRACT FROM AUTHOR]