Global Change Center

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Analysis of environmental and economic impacts of hydropower imports for New York City through 2050
Calder, Ryan S. D.; Borsuk, Mark E.; Robinson, Celine (Duke University Nicholas Institute for Environmental Policy Solutions, 2020-10-13)
Indian Point Energy Center (IPEC), a nuclear generating facility that has provided roughly 15 TW·h per year of low-emissions power to the New York City area, will close by 2021. There has been debate over the potential responses to the closure of IPEC which include the development of new generation and transmission infrastructure. This derives in part from difficulties in comparing direct and indirect costs and benefits and environmental and social impacts, which vary substantially across energy alternatives. In particular, the potential role of increased imports of hydropower from Canada to the New York City area has been controversial because of large upfront capital costs and uncertain benefits relative to alternatives such as increased build-out of Downstate New York offshore wind and solar.
Chasing Water in a Rapidly Changing World
Richter, Brian D. (Virginia Tech. University Libraries, 2017-04-07)
Water shortages are now affecting half the world’s population, disrupting food and energy security as well as urban water supplies in many cities. The overuse of water and associated drying of rivers, lakes, and aquifers has become a leading cause of freshwater species imperilment. Climate change forecasts foretell even greater challenges in many water-scarce regions. These threats to our water future can be ameliorated, but it will require bold and concerted action on the part of governments, city leaders, and farmers. This presentation will highlight the key solutions that must be implemented. “Brian Richter has been a global leader in water science and conservation for more than 25 years. He is the Chief Scientist for the Global Water Program of The Nature Conservancy, an international conservation organization, where he promotes sustainable water use and management with governments, corporations, and local communities. He is also the President of Sustainable Waters, a global water education organization. Brian has consulted on more than 120 water projects worldwide. He serves as a water advisor to some of the world’s largest corporations, investment banks, and the United Nations, and has testified before the U.S. Congress on multiple occasions. He also teaches a course on Water Sustainability at the University of Virginia. Brian has developed numerous scientific tools and methods to support river protection and restoration efforts, including the Indicators of Hydrologic Alteration software that is being used by water managers and scientists worldwide. Brian was featured in a BBC documentary with David Attenborough on “How Many People Can Live on Planet Earth?” He has published many scientific papers on the importance of ecologically sustainable water management in international science journals, and co-authored a book with Sandra Postel entitled Rivers for Life: Managing Water for People and Nature (Island Press, 2003). His new book, Chasing Water: A Guide for Moving from Scarcity to Sustainability, was published by Island Press in June 2014.” - National Geographic, http://voices.nationalgeographic.com/author/brichter/
Coupled Human-Natural Modeling for Hydroelectric Development: Understanding the Health Impacts of America’s Renewable Energy Imports
Calder, Ryan S. D. (Duke University, 2019)
Hydropower accounts for 71% of renewable electrical generation worldwide, and installed capacity may more than double by 2050. Major hydroelectric projects involve construction of reservoirs to buffer the periodicity of river discharge, meaning hydropower typically does not suffer from supply intermittency of other renewables such as wind and solar. Meanwhile, average greenhouse gas emissions are likely substantially lower than fossil fuel alternatives per unit energy produced. Domestic hydropower production in the United States is unlikely to increase substantially in the foreseeable future, but imports from Canada play an increasingly important role in achieving renewable energy targets in northern U.S. markets....
COVID-19 Reveals Vulnerabilities of the Food–Energy–Water Nexus to Viral Pandemics
Calder, Ryan S. D.; Grady, Caitlin; Jeuland, Marc; Kirchhoff, Christine J.; Hale, Rebecca L.; Muenich, Rebecca L. (American Chemical Society, 2021)
Food, energy, and water (FEW) sectors are inextricably linked, making one sector vulnerable to disruptions in another. Interactions between FEW systems, viral pandemics, and human health have not been widely studied. We mined scientific and news/media articles for causal relations among FEW and COVID-19 variables and qualitatively characterized system dynamics. Food systems promoted the emergence and spread of COVID-19, leading to illness and death. Major supply-side breakdowns were avoided (likely due to low morbidity/mortality among working-age people). However, COVID-19 and physical distancing disrupted labor and capital inputs and stressed supply chains, while creating economic insecurity among the already vulnerable poor. This led to demand-side FEW insecurities, in turn increasing susceptibility to COVID-19 among people with many comorbidities. COVID-19 revealed trade-offs such as allocation of water to hygiene versus to food production and disease burden avoided by physical distancing versus disease burden from increased FEW insecurities. News/media articles suggest great public interest in FEW insecurities triggered by COVID-19 interventions among individuals with low COVID-19 case-fatality rates. There is virtually no quantitative analysis of any of these trade-offs or feedbacks. Enhanced quantitative FEW and health models are urgently needed as future pandemics are likely and may have greater morbidity and mortality than COVID-19.
Living in the Anthropocene: Science, Sustainability and Society
Tewksbury, Joshua (Virginia Tech. University Libraries, 2016-04-21)
Dr. Joshua Tewksbury is an ecologist, conservation biologist, and planetary health scientist with experience both in academia and in civil society. In addition to his appointment at Future Earth, Tewksbury is also a research professor at the University of Colorado, Boulder, and a senior scholar in the School of Global Environmental Sustainability at Colorado State University. During his visit, Tewksbury met with students in the Interfaces of Global Change Interdisciplinary Graduate Education Program. "Dr. Tewksbury is leading the charge to advance conservation and sustainability initiatives on a global scale," said William A. Hopkins, director of the Global Change Center. As director of the U.S. office of Future Earth, he is working with a broad international coalition of groups like the United Nations to pursue what has been called "possibly the largest, most ambitious international research program ever undertaken. As Virginia Tech is poised to advance its collective strengths in the environmental sciences, we are thrilled to have such an outstanding leader visit Blacksburg to engage in a community-wide discussion about critical issues facing our planet." Tewksbury was previously the Walker Professor of Natural History at the University of Washington, with appointments both in the department of biology and the College of the Environment, where his work focused on major global change issues, including the impacts of climate change on biodiversity, the potential of landscape connectivity to mitigate the impacts of climate change, and the impacts of species loss on ecosystem function. In addition to more than a decade of academic work, Tewksbury also served as the founding director of the Luc Hoffmann Institute at WWF, a global research center based in Switzerland focused on the co-creation of multi-disciplinary research. As director, Tewksbury launched over a dozen research projects, including work on the Food-Energy-Water nexus in South-East Asia, development corridors in East Africa, global mapping of threats to biodiversity, and the development of regionally-appropriate low-carbon sustainability targets for urban areas. Tewksbury's current research interests include studies of direct and indirect effects of climate change on food security at large spatial scales, the potential of large-scale restoration to serve multiple human and biodiversity goals, and the contribution of science to large scale planetary health issues.
Modeling Temperature Effects on Population Density of the Dengue Mosquito Aedes aegypti
El Moustaid, Fadoua; Johnson, Leah R. (MDPI, 2019-11-07)
Mosquito density plays an important role in the spread of mosquito-borne diseases such as dengue and Zika. While it remains very challenging to estimate the density of mosquitoes, modelers have tried different methods to represent it in mathematical models. The goal of this paper is to investigate the various ways mosquito density has been quantified, as well as to propose a dynamical system model that includes the details of mosquito life stages leading to the adult population. We first discuss the mosquito traits involved in determining mosquito density, focusing on those that are temperature dependent. We evaluate different forms of models for mosquito densities based on these traits and explore their dynamics as temperature varies. Finally, we compare the predictions of the models to observations of Aedes aegypti abundances over time in Vitòria, Brazil. Our results indicate that the four models exhibit qualitatively and quantitatively different behaviors when forced by temperature, but that all seem reasonably consistent with observed abundance data.
Predicting temperature-dependent transmission suitability of bluetongue virus in livestock
El Moustaid, Fadoua; Thornton, Zorian; Slamani, Hani; Ryan, Sadie J.; Johnson, Leah R. (2021-07-30)
The transmission of vector-borne diseases is governed by complex factors including pathogen characteristics, vector–host interactions, and environmental conditions. Temperature is a major driver for many vector-borne diseases including Bluetongue viral (BTV) disease, a midge-borne febrile disease of ruminants, notably livestock, whose etiology ranges from mild or asymptomatic to rapidly fatal, thus threatening animal agriculture and the economy of affected countries. Using modeling tools, we seek to predict where the transmission can occur based on suitable temperatures for BTV. We fit thermal performance curves to temperature-sensitive midge life-history traits, using a Bayesian approach. We incorporate these curves into S(T), a transmission suitability metric derived from the disease’s basic reproductive number, 𝑅0. This suitability metric encompasses all components that are known to be temperature-dependent. We use trait responses for two species of key midge vectors, Culicoides sonorensis and Culicoides variipennis present in North America. Our results show that outbreaks of BTV are more likely between 15∘ C and 34∘ C, with predicted peak transmission risk at 26 ∘ C. The greatest uncertainty in S(T) is associated with the following: the uncertainty in mortality and fecundity of midges near optimal temperature for transmission; midges’ probability of becoming infectious post-infection at the lower edge of the thermal range; and the biting rate together with vector competence at the higher edge of the thermal range. We compare three model formulations and show that incorporating thermal curves into all three leads to similar BTV risk predictions. To demonstrate the utility of this modeling approach, we created global suitability maps indicating the areas at high and long-term risk of BTV transmission, to assess risk and to anticipate potential locations of disease establishment.
Risk tradeoffs associated with traditional food advisories for Labrador Inuit
Calder, Ryan S. D.; Bromage, Sabri; Sunderland, Elsie M. (Elsevier, 2019-01-01)
The traditional Inuit diet includes wild birds, fish and marine mammals, which can contain high concentrations of the neurotoxicant methylmercury (MeHg). Hydroelectric development may increase MeHg concentrations in traditional foods. Consumption advisories are often used to mitigate such risks and can result in reduced intake of traditional foods. Data from a dietary survey, MeHg exposure assessment and risk analysis for individuals in three Inuit communities in Labrador, Canada (n = 1145) in 2014 indicate reducing traditional food intake is likely to exacerbate deficiencies in n-3 polyunsaturated fatty acids and vitamins B12 and B2. Traditional foods accounted for < 5% of per-capita calories but up to 70% of nutrients consumed. Although consumption advisories could lower neurodevelopmental risks associated with an increase in MeHg exposure (90th-percentile ∆IQ = − 0.12 vs. − 0.34), they may lead to greater risks of cardiovascular mortality (90th-percentile increase: + 58% to + 116% vs. + 25%) and cancer mortality (90th-percentile increase + 2% to + 4% vs. no increase). Conversely, greater consumption of locally caught salmon mostly unaffected by hydroelectric flooding would lower all these risks (90th-percentile ∆IQ = + 0.4; cardiovascular risk: − 45%; cancer risk: − 1.4%). We thus conclude that continued consumption of traditional foods is essential for Inuit health in these communities.
Should We Trust Science? Perspectives from the History and Philosophy of Science
Oreskes, Naomi (Virginia Tech. University Libraries, 2015-09-02)
The Global Change Center at Virginia Tech welcomed Dr. Naomi Oreskes, Harvard historian and author, for a Distinguished Lecture on September 2, 2015, at 4:00 p.m. at the Lyric Theatre in Blacksburg, VA. Dr. Oreskes is a professor of the history of science and affiliated professor of Earth and planetary sciences at Harvard University. Her research focuses on the earth and environmental sciences, with a particular interest in understanding scientific consensus and dissent. Dr. Oreskes has received international acclaim for her 2010 book, "Merchants of Doubt, How a Handful of Scientists Obscured the Truth on Issues from Tobacco to Global Warming," co-authored with Erik M. Conway. It was shortlisted for the Los Angeles Time Book Prize, received the 2011 Watson-Davis Prize from the History of Science Society, and was recently adapted into a documentary film. Dr. Oreskes' visit represents the second in a Public Distinguished Lecture Series sponsored by the Global Change Center at Virginia Tech. The lecture series is designed to bring some of the world's leading scholars to the Blacksburg community to discuss critical environmental and societal issues in an open forum.
Spiculogenesis and biomineralization in early sponge animals
Tang, Qing; Wan, Bin; Yuan, Xunlai; Muscente, A. D.; Xiao, Shuhai (Springer Nature, 2019-07-26)
Most sponges have biomineralized spicules. Molecular clocks indicate sponge classes diverged in the Cryogenian, but the oldest spicules are Cambrian in age. Therefore, sponges either evolved spiculogenesis long after their divergences or Precambrian spicules were not amenable to fossilization. The former hypothesis predicts independent origins of spicules among sponge classes and presence of transitional forms with weakly biomineralized spicules, but this prediction has not been tested using paleontological data. Here, we report an early Cambrian sponge that, like several other early Paleozoic sponges, had weakly biomineralized and hexactine-based siliceous spicules with large axial filaments and high organic proportions. This material, along with Ediacaran microfossils containing putative non-biomineralized axial filaments, suggests that Precambrian sponges may have had weakly biomineralized spicules or lacked them altogether, hence their poor record. This work provides a new search image for Precambrian sponge fossils, which are critical to resolving the origin of sponge spiculogenesis and biomineralization.

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