Browsing by Subject "Climate"
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Item Open Access Aligning NYISO's Carbon Pricing with Existing Climate Policy(2019-04-24) Stutt, JordanStates across the Northeast and Mid-Atlantic have implemented particularly ambitious policies to deploy clean energy and reduce carbon dioxide (CO2) emissions from the electric sector. These policies create a challenge for the region's electric grid operators, who must oversee the achievement of clean energy and climate targets while ensuring grid reliability and maintaining cost-effective electric service. To harmonize those objectives, three of the region’s grid operators have considered incorporating the cost of CO2 emissions into their competitive wholesale electricity markets. This project examines the effects of the carbon pricing policy proposed by NYISO (New York's grid operator) and offers recommendations on how such a policy could be designed to maximize low-cost emissions reductions and help to achieve the state's existing climate and clean energy objectives.Item Open Access AN EVALUATION OF CORPORATE VOLUNTARY CLIMATE ACTIONS: A FOCUS ON THE RENTAL CAR & TRUCK INDUSTRY(2010-04-30T02:28:31Z) McCorkle, BetsyClimate change is a global problem with social, economic, and environmental consequences, resulting primarily from reliance on fossil fuels like coal and oil. In the absence of federal climate policy, some companies have taken the initiative to voluntarily take actions to measure and disclosure their carbon emissions and related climate actions. A non-profit organization, Climate Counts, believes that business has the power to change the outcomes related to climate change, and consumers have the power to change business. Climate Counts provides a scoring system, which is an effort to bring consumers and companies together in the fight against climate change. By providing a score of 0-100 to individual companies, Climate Counts compares companies with industries on their published and documented commitments to address climate change. This Master’s Project develops the scorecard for the rental car and truck industry. The evaluation includes six companies in the rental car and truck industry, all of which have annual revenues of over one billion dollars. The scores for the six companies varied from zero to 24 with a median score of 18.5. While the top score of 24 held by the Avis Budget Group and Penske demonstrates that they are their industry’s leaders in corporate climate actions, the relatively low score also indicates that car rental industry has room for significant improvements in voluntary climate change action. Companies that choose to utilize and respond to this evaluation are leading the charge in one of the fastest growing corporate disciplines. They have the willingness to develop and implement a climate strategy that works for executives, employees, customers, and other stakeholders.Item Open Access Assessing the Environmental Sustainability Potential of BRI Countries under the Five Connectivities Framework(2019-04-26) Guo, Jiaxin; Nwe, Mya; Qazi, Zainab; Zhou, ShuyiChina’s ambitious vision for the Belt and the Road initiative (BRI) marks a global milestone for economic and political cooperation across Asia, Europe, Africa, and South America. With more than 100 member countries accounting for around one-third of the world trade, BRI’s geographical scope is unmatched. Despite China’s vision for “green” development, BRI’s trillion-dollar infrastructure and energy projects introduce immense environmental risks. Carbon-intensive investments and recipient countries’ asymmetry in addressing environmental issues pose challenges in sustaining green development and meeting the climate goals of the Paris Agreement. Our research investigates China’s vision for green investments by gauging BRI countries’ potential to support environmentally sustainable projects. The study assesses the environmental sustainability potential (ESP) for each country’s performance on climate and energy across the “Five Connectivity Framework”, identified by the Chinese government as the BRI cooperation priority across policy, trade, finance, facilities, and people-to-people connections. The ESP index scores BRI countries across these five connectivities using key environmental indicators. The analysis also presents a case study of BRI countries along the three Asian economic corridors to identify trends and provide specific recommendations for environmental safeguards.Item Open Access Assessment of Smallholder Training Programs in Food Sector Climate Strategies(2022-04-21) Grigg, MarjorieThe future outcomes of climate change, the food sector, and supplier land management are codependent. The food sector is responsible for 37% of global greenhouse gas emissions—predominantly due to land use practices—while also facing decreased productivity as climate change worsens. As food companies and suppliers seek to increase yields, they run the risk of exacerbating this dynamic by intensifying and expanding production. Smallholder farmers (SHF) will play a key role in determining the trajectory of the sector’s land use, as they are particularly vulnerable to climate change and the need to boost food production for household income and consumption. Reducing emissions and mitigating climate risk in the food sector is therefore contingent upon strategic engagements that incentivize and support farmers—particularly SHFs—to transition to land use practices that boost productivity and reduce emissions across supply chains. Encouragingly, food companies are increasingly setting targets to reduce their emissions and establishing climate strategies to address supply risk. Many companies also have long-standing training programs to support SHFs, typically through philanthropic and Corporate Social Responsibility initiatives. However, even where companies are both taking climate action and engaging with small farmers, it is unclear how or if these initiatives are integrated within corporate climate strategy. Alignment across these efforts could accelerate progress by leveraging ongoing programming, and maximize investments and results by identifying synergies across these interconnected objectives. Failing to integrate these initiatives could lead to ineffective investment of limited funding; duplication or counteraction of efforts; and ultimately failure to optimize outcomes across these vital interventions for the sector. In sustainable business strategy, “embedded” initiatives (in which sustainability concerns are integrated into a company’s core strategy) are recognized as more effective than “bolt on” strategies, which tout “green initiatives and social philanthropy,” but are separate from the company’s core strategy. Beyond business strategy, it will be important for companies already investing in initiatives with smallholders to understand how these programs are “embedded into” or “bolted onto” their broader climate action if they are to optimize their efforts to bolster supply, reduce emissions, and support livelihoods. Given the importance of small farmers in creating a sustainable and viable trajectory for global food production and climate action, this study assesses the degree to which companies’ smallholder training programs are embedded within their corporate aims to reduce emissions and mitigate supply risk. Any learnings or areas for improvement will not only inform Corporate Sustainability Officers looking to scale their impact, but will also provide an important road map for companies newly investing in these types of interventions within their supply chains. To improve the level of comparability within this sample, I limited the study area to food companies with 1) emissions targets verified by the Science-based Targets Initiative; 2) climate strategies reported to the same environmental disclosure platform, the Carbon Disclosure Project (CDP); and 3) SHF training programs in Latin America with the same implementing NGO, TechnoServe. I begin by examining companies’ publicly facing sustainability communications, such as Corporate Impact Reports. I examine these publications using the four capitals of environmental economics (natural capital, produced capital, and human and social capitals) to assess companies’ expressed priorities and concerns when communicating to stakeholders about sustainability efforts within their supply chains. I then draw on the principles of materiality and sustainable business strategy to track how supply chain concerns flow throughout companies’ climate strategies, as reported through their CDP “Climate Change Surveys.” I examine how those supply chain concerns translate (or fail to translate) into concrete targets, and then compare these targets with the metrics for success defined in their training programs. I use this alignment as a metric to evaluate the embeddedness of those programs into broader corporate climate action, and posit initial considerations to better integrate smallholders into more effective corporate climate strategies. Findings within this sample indicate that companies emphasizing broad social outcomes for their farmers—rather than explicit land use outcomes within their value chains—are motivated by “social philanthropy” rather than “embedded sustainability,” and, because of this, fail to leverage their investments to drive progress against corporate climate action. While the limited scope of this study does not allow for generalizable conclusions, it highlights initial trends and considerations that can be used by Corporate Sustainability Officers and implementers such as TechnoServe with the power to better align these climate initiatives and optimize their impact. Companies with “embedded” training programs distinguished themselves by training their direct suppliers, aligning training outcomes with internal supply standards, including specific land use concerns within these standards and public sustainability communications, and addressing challenges farmers may face in complying with those standards (for example facilitating access to credit). All “embedded” programs acted within a value chain that accounts for at least 30% of the companies’ revenues. Based on these findings, it will be important for Corporate Sustainability Officers managing “bolt on” farmer engagement programs to identify an achievable, initial set of sourcing standards that can bridge the gap between their farmer training activities and their supply-chain and climate interventions. Third-party certifications and implementing partners could facilitate this transition by providing verification standards and adapting ongoing training curricula to meet these standards, respectively. Because many of these programs are already promoting best practices similar to embedded programs’ sustainable sourcing criteria, a key challenge for corporate sustainability teams will be to measure uptake of those practices in relation to emissions outcomes, and to concentrate training within their companies’ sourcing channels. It will therefore be essential for these teams to understand and mitigate the barriers their sourcing counterparts may face in making direct investments with local suppliers. Conversely, companies with “embedded” training programs could leverage their land use outcomes to establish more rigorous emissions targets. For implementers working with both types of companies, it will be vital to understand their role in making the above transitions feasible and desirable for food companies in order to optimize results for the climate, food production, and the producers who depend on both.Item Open Access Avian Population Trends in the Pacific Northwest(2009-04-24T13:24:27Z) Schoenbaechler, CaimeeLand bird populations are facing a growing number of threats including habitat loss, climate change, loss of stratospheric ozone, and toxic pollution. In response to land bird monitoring needs by federal agencies, the High Cascades Ranger District in Prospect, OR, began implementation of mist-netting efforts as established by the Monitoring Avian Productivity and Survivorship (MAPS) program in 1994. Site specific population trends were analyzed using regression and non metric multi-dimensional scaling (NMS) ordination analysis over a fourteen year period, and then compared to regional trends using the MAPS web-based query. Of thirty nine species, four demonstrated significantly increasing trends, while two species demonstrated significantly decreasing trends in regression analysis. Site-specific trends were consistent with regional trends. Regression analysis also revealed a significant correlation between abundance and climate factors, specifically temperature and precipitation. The NMS ordination did not reveal clear ecological trends, but did show that species composition varies with net placement. Climate factors, life history strategy, productivity, and survivorship were factors used to interpret population trends. Continued MAPS monitoring will facilitate our understanding of shifts in avian populations and their ranges that will most likely occur in light of increased land use and climate change.Item Open Access Avoided Deforestation in the Democratic Republic of Congo(2008-12-05T15:06:25Z) McClanahan, PaigeDeforestation and forest degradation account for one fifth of greenhouse gas emissions around the world, second only to fossil fuel combustion. While the Kyoto Protocol has no mechanism that aims to stop forest loss, climate negotiators have begun to devise a program – to be built into Kyoto’s successor – that would reward developing countries for “avoiding deforestation” that otherwise would have occurred. Reduced Emissions from Deforestation and Forest Degradation, or REDD, certainly offers a lot of promise: by allowing poor forested countries to earn, and then sell, tradable carbon credits on a global carbon market, the program could generate a substantial amount of revenue. And many observers have argued that these funds could be used to help fight poverty in forest-dwelling communities. But REDD implementation would not be easy: it would require the technical capacity to measure and monitor forest cover and the governance capacity to both stop forest loss and distribute REDD-derived income. These challenges would be particularly daunting in countries that already struggle to govern effectively. To consider this issue in greater depth, this paper uses the Democratic Republic of Congo as a lens through which to examine the challenges of REDD implementation, especially with regard to how the program might impact the country’s poor forest dwellers. The paper concludes that, in the face of such governance challenges, the DRC should take concrete steps to create a facilitating environment for the program’s implementation. These steps include increasing investment in the forest sector, strengthening land tenure among forest-dwelling people, devolving more control over forests to local actors, and taking measures to increase transparency and combat corruption.Item Open Access Biogeography in deep time - What do phylogenetics, geology, and paleoclimate tell us about early platyrrhine evolution?(Mol Phylogenet Evol, 2015-01) Kay, Richard FrederickMolecular data have converged on a consensus about the genus-level phylogeny of extant platyrrhine monkeys, but for most extinct taxa and certainly for those older than the Pleistocene we must rely upon morphological evidence from fossils. This raises the question as to how well anatomical data mirror molecular phylogenies and how best to deal with discrepancies between the molecular and morphological data as we seek to extend our phylogenies to the placement of fossil taxa. Here I present parsimony-based phylogenetic analyses of extant and fossil platyrrhines based on an anatomical dataset of 399 dental characters and osteological features of the cranium and postcranium. I sample 16 extant taxa (one from each platyrrhine genus) and 20 extinct taxa of platyrrhines. The tree structure is constrained with a "molecular scaffold" of extant species as implemented in maximum parsimony using PAUP with the molecular-based 'backbone' approach. The data set encompasses most of the known extinct species of platyrrhines, ranging in age from latest Oligocene (∼26 Ma) to the Recent. The tree is rooted with extant catarrhines, and Late Eocene and Early Oligocene African anthropoids. Among the more interesting patterns to emerge are: (1) known early platyrrhines from the Late Oligocene through Early Miocene (26-16.5Ma) represent only stem platyrrhine taxa; (2) representatives of the three living platyrrhine families first occur between 15.7 Ma and 13.5 Ma; and (3) recently extinct primates from the Greater Antilles (Cuba, Jamaica, Hispaniola) are sister to the clade of extant platyrrhines and may have diverged in the Early Miocene. It is probable that the crown platyrrhine clade did not originate before about 20-24 Ma, a conclusion consistent with the phylogenetic analysis of fossil taxa presented here and with recent molecular clock estimates. The following biogeographic scenario is consistent with the phylogenetic findings and climatic and geologic evidence: Tropical South America has been a center for platyrrhine diversification since platyrrhines arrived on the continent in the middle Cenozoic. Platyrrhines dispersed from tropical South America to Patagonia at ∼25-24 Ma via a "Paraná Portal" through eastern South America across a retreating Paranense Sea. Phylogenetic bracketing suggests Antillean primates arrived via a sweepstakes route or island chain from northern South America in the Early Miocene, not via a proposed land bridge or island chain (GAARlandia) in the Early Oligocene (∼34 Ma). Patagonian and Antillean platyrrhines went extinct without leaving living descendants, the former at the end of the Early Miocene and the latter within the past six thousand years. Molecular evidence suggests crown platyrrhines arrived in Central America by crossing an intermittent connection through the Isthmus of Panama at or after 3.5Ma. Any more ancient Central American primates, should they be discovered, are unlikely to have given rise to the extant Central American taxa in situ.Item Open Access Changes in U.S. Residential Monthly Energy Use per Capita: 1990-2017(2019) Yang, XiaoxuanResidential energy consumption represents a large share of total end use energy and shows strong correlation with monthly cooling and heating degree days. This study focuses on quantifying temporal change in the relationship between monthly degree days and monthly U.S. residential use of electricity and natural gas for each of the 48 contiguous states from 1990 to 2017. We introduce a single degree day predicator to characterize the non-linear relationship between degree-day and state-level electricity and natural gas use. By looking at trends in three DD-energy use coordinates and curvature from single quadratic fits on a year-by-year and state-by-state basis, we confirm the non-linear relationship between DD and residential energy use and reveal processes that might influence the relationship. We find that residential electricity energy use has become more sensitive to seasonal fluctuations in temperature in most states. While the lowest electricity use per year has risen, natural gas use has fallen since 1990 in most states. We further group the states into 17 classes for electricity use and 21 classes for natural gas use based on combinations of temporal trends in quadratic curve variables. These large groupings for electricity have shown a similar spatial distribution as that of the climate regions defined by the U.S. Department of Energy, reaffirming temperature and humidity as influential factors in the climate-energy relationship. We also compare our results with the household and end uses information from U.S. Energy Information Administration’s Residential Energy Consumption (REC) Surveys and recognize electricity as a growing heating source in all U.S. regions. We further address economic development, energy efficiency of end uses, and building codes as potential trends that affect the relationship between degree day and residential energy use at national, regional and state levels.
Item Open Access City of Greenville, NC Greenhouse Gas Accounting and Emissions Reduction Plan(2022-04-22) Rosenthal, Regan; Patchett, MaggieAs we near the International Panel on Climate Change’s 2030 deadline to halve global greenhouse gas (GHG) emissions, cities are being called upon to proactively manage the negative effects of urbanization. Greenville, North Carolina aims to join the growing list of American cities who are taking responsibility for their role in climate change by generating a comprehensive inventory of the GHGs emitted by their municipal operations. Our team’s objective was to catalog the city’s greenhouse gas footprint and make recommendations according to our findings, working in coordination with the City Manager of Greenville, NC. Specifically, we were tasked with creating an emissions inventory that could be used as the city’s baseline, against which future years’ inventories could be measured and compared to track reductions over time. We produced a baseline GHG emissions inventory of municipal operations from fiscal year 2019, as that was the most recent fiscal year which experienced no operational interruptions from the Covid-19 pandemic. The inventory identifies activities and sectors with high emissions contributions, and we used this data to recommend the emissions reductions measures that would be most beneficial to the city. Our GHG emissions accounting methodology utilized the standardized framework for local governments created by ICLEI’s Cities for Climate Protection Campaign. Using ClearPath—ICLEI’s GHG emissions inventory tool—we generated an emissions report which includes an emissions inventory, projections of future emissions, and forecasts that predict the effects various potential reduction measures might have on Greenville’s GHG footprint over a 10-year period. The emissions report contributed to the development of a sustainability project work plan with benchmarks and targets to track municipal emissions reduction performance over time. Key Findings: 1. The majority of Greenville’s emissions are Scope 1, or direct emissions from operational activity. 2. The greatest contributing sector of municipal operations to the city’s emissions inventory is Vehicle Fleet. In this instance, “Vehicle Fleet” encompasses both municipal vehicles and transit vehicles, though future inventories should distinguish between the vehicle types to better target possible areas for emissions reductions. 3. Greenville’s emissions per capita for municipal operations are not directly comparable to other North Carolina municipalities. The City of Greenville does not have operational control over some activities and sectors included in their peers’ inventories of government operations. Key Recommendations: 1. Implement energy efficiency improvements within Greenville’s vehicle fleet to reduce the sector’s contribution and the overall emissions footprint for municipal operations. 2. Disaggregate data into individual records within ClearPath to better understand which activities by sector have the largest contribution to better select emissions reduction measures. 3. If data is available, use the same process to generate a 2005 emissions inventory for the purposes of setting goals and measuring progress. 4. Continue the momentum from this project by making sustainability a permanent fixture within city operations through the hiring of a sustainability professional.Item Open Access Climate drives the geography of marine consumption by changing predator communities.(Proceedings of the National Academy of Sciences of the United States of America, 2020-11) Whalen, Matthew A; Whippo, Ross DB; Stachowicz, John J; York, Paul H; Aiello, Erin; Alcoverro, Teresa; Altieri, Andrew H; Benedetti-Cecchi, Lisandro; Bertolini, Camilla; Bresch, Midoli; Bulleri, Fabio; Carnell, Paul E; Cimon, Stéphanie; Connolly, Rod M; Cusson, Mathieu; Diskin, Meredith S; D’Souza, Elrika; Flores, Augusto AV; Fodrie, F Joel; Galloway, Aaron WE; Gaskins, Leo C; Graham, Olivia J; Hanley, Torrance C; Henderson, Christopher J; Hereu, Clara M; Hessing-Lewis, Margot; Hovel, Kevin A; Hughes, Brent B; Hughes, A Randall; Hultgren, Kristin M; Jänes, Holger; Janiak, Dean S; Johnston, Lane N; Jorgensen, Pablo; Kelaher, Brendan P; Kruschel, Claudia; Lanham, Brendan S; Lee, Kun-Seop; Lefcheck, Jonathan S; Lozano-Álvarez, Enrique; Macreadie, Peter I; Monteith, Zachary L; O’Connor, Nessa E; Olds, Andrew D; O’Leary, Jennifer K; Patrick, Christopher J; Pino, Oscar; Poore, Alistair GB; Rasheed, Michael A; Raymond, Wendel W; Reiss, Katrin; Rhoades, O Kennedy; Robinson, Max T; Ross, Paige G; Rossi, Francesca; Schlacher, Thomas A; Seemann, Janina; Silliman, Brian R; Smee, Delbert L; Thiel, Martin; Unsworth, Richard KF; van Tussenbroek, Brigitta I; Vergés, Adriana; Yeager, Mallarie E; Yednock, Bree K; Ziegler, Shelby L; Duffy, J EmmettThe global distribution of primary production and consumption by humans (fisheries) is well-documented, but we have no map linking the central ecological process of consumption within food webs to temperature and other ecological drivers. Using standardized assays that span 105° of latitude on four continents, we show that rates of bait consumption by generalist predators in shallow marine ecosystems are tightly linked to both temperature and the composition of consumer assemblages. Unexpectedly, rates of consumption peaked at midlatitudes (25 to 35°) in both Northern and Southern Hemispheres across both seagrass and unvegetated sediment habitats. This pattern contrasts with terrestrial systems, where biotic interactions reportedly weaken away from the equator, but it parallels an emerging pattern of a subtropical peak in marine biodiversity. The higher consumption at midlatitudes was closely related to the type of consumers present, which explained rates of consumption better than consumer density, biomass, species diversity, or habitat. Indeed, the apparent effect of temperature on consumption was mostly driven by temperature-associated turnover in consumer community composition. Our findings reinforce the key influence of climate warming on altered species composition and highlight its implications for the functioning of Earth's ecosystems.Item Open Access Comparing the model-simulated global warming signal to observations using empirical estimates of unforced noise.(Sci Rep, 2015-04-21) ◦Brown, P.T., W. Li, E.C. Cordero, S.A. MaugetThe comparison of observed global mean surface air temperature (GMT) change to the mean change simulated by climate models has received much public and scientific attention. For a given global warming signal produced by a climate model ensemble, there exists an envelope of GMT values representing the range of possible unforced states of the climate system (the Envelope of Unforced Noise; EUN). Typically, the EUN is derived from climate models themselves, but climate models might not accurately simulate the correct characteristics of unforced GMT variability. Here, we simulate a new, empirical, EUN that is based on instrumental and reconstructed surface temperature records. We compare the forced GMT signal produced by climate models to observations while noting the range of GMT values provided by the empirical EUN. We find that the empirical EUN is wide enough so that the interdecadal variability in the rate of global warming over the 20(th) century does not necessarily require corresponding variability in the rate-of-increase of the forced signal. The empirical EUN also indicates that the reduced GMT warming over the past decade or so is still consistent with a middle emission scenario's forced signal, but is likely inconsistent with the steepest emission scenario's forced signal.Item Open Access Decadal biomass increment in early secondary succession woody ecosystems is increased by CO2 enrichment.(Nature communications, 2019-02) Walker, Anthony P; De Kauwe, Martin G; Medlyn, Belinda E; Zaehle, Sönke; Iversen, Colleen M; Asao, Shinichi; Guenet, Bertrand; Harper, Anna; Hickler, Thomas; Hungate, Bruce A; Jain, Atul K; Luo, Yiqi; Lu, Xingjie; Lu, Meng; Luus, Kristina; Megonigal, J Patrick; Oren, Ram; Ryan, Edmund; Shu, Shijie; Talhelm, Alan; Wang, Ying-Ping; Warren, Jeffrey M; Werner, Christian; Xia, Jianyang; Yang, Bai; Zak, Donald R; Norby, Richard JIncreasing atmospheric CO2 stimulates photosynthesis which can increase net primary production (NPP), but at longer timescales may not necessarily increase plant biomass. Here we analyse the four decade-long CO2-enrichment experiments in woody ecosystems that measured total NPP and biomass. CO2 enrichment increased biomass increment by 1.05 ± 0.26 kg C m-2 over a full decade, a 29.1 ± 11.7% stimulation of biomass gain in these early-secondary-succession temperate ecosystems. This response is predictable by combining the CO2 response of NPP (0.16 ± 0.03 kg C m-2 y-1) and the CO2-independent, linear slope between biomass increment and cumulative NPP (0.55 ± 0.17). An ensemble of terrestrial ecosystem models fail to predict both terms correctly. Allocation to wood was a driver of across-site, and across-model, response variability and together with CO2-independence of biomass retention highlights the value of understanding drivers of wood allocation under ambient conditions to correctly interpret and predict CO2 responses.Item Open Access Dual impact of elevated temperature on plant defence and bacterial virulence in Arabidopsis.(Nature communications, 2017-11-27) Huot, Bethany; Castroverde, Christian Danve M; Velásquez, André C; Hubbard, Emily; Pulman, Jane A; Yao, Jian; Childs, Kevin L; Tsuda, Kenichi; Montgomery, Beronda L; He, Sheng YangEnvironmental conditions profoundly affect plant disease development; however, the underlying molecular bases are not well understood. Here we show that elevated temperature significantly increases the susceptibility of Arabidopsis to Pseudomonas syringae pv. tomato (Pst) DC3000 independently of the phyB/PIF thermosensing pathway. Instead, elevated temperature promotes translocation of bacterial effector proteins into plant cells and causes a loss of ICS1-mediated salicylic acid (SA) biosynthesis. Global transcriptome analysis reveals a major temperature-sensitive node of SA signalling, impacting ~60% of benzothiadiazole (BTH)-regulated genes, including ICS1 and the canonical SA marker gene, PR1. Remarkably, BTH can effectively protect Arabidopsis against Pst DC3000 infection at elevated temperature despite the lack of ICS1 and PR1 expression. Our results highlight the broad impact of a major climate condition on the enigmatic molecular interplay between temperature, SA defence and function of a central bacterial virulence system in the context of a widely studied susceptible plant-pathogen interaction.Item Open Access Elevational ranges of birds on a tropical montane gradient lag behind warming temperatures.(PloS one, 2011-01) Forero-Medina, German; Terborgh, John; Socolar, S Jacob; Pimm, Stuart LBackground
Species may respond to a warming climate by moving to higher latitudes or elevations. Shifts in geographic ranges are common responses in temperate regions. For the tropics, latitudinal temperature gradients are shallow; the only escape for species may be to move to higher elevations. There are few data to suggest that they do. Yet, the greatest loss of species from climate disruption may be for tropical montane species.Methodology/principal findings
We repeat a historical transect in Peru and find an average upward shift of 49 m for 55 bird species over a 41 year interval. This shift is significantly upward, but also significantly smaller than the 152 m one expects from warming in the region. To estimate the expected shift in elevation we first determined the magnitude of warming in the locality from historical data. Then we used the temperature lapse rate to infer the required shift in altitude to compensate for warming. The range shifts in elevation were similar across different trophic guilds.Conclusions
Endothermy may provide birds with some flexibility to temperature changes and allow them to move less than expected. Instead of being directly dependent on temperature, birds may be responding to gradual changes in the nature of the habitat or availability of food resources, and presence of competitors. If so, this has important implications for estimates of mountaintop extinctions from climate change.Item Open Access Emerging Perspectives on Climate Risk: Current Business Leaders & Future Business Leaders(2018-04-27) Blake, Adam; Bonney, Devon; Geoffrey, Luke; Gibson, Amanda; Duggan, AmandaIncreasingly, global companies have to balance short-term objectives with longer-term opportunities in response to a changing climate. Corporations have a great deal to gain from reframing climate-related risks into opportunities for growth, innovation, and operational efficiency. In turn, business schools have an opportunity to train emerging business leaders in mitigation and response strategies to address environmental and climate-related risk. This multi-faceted research project examines how corporations view non-financial risk, particularly as it relates to climate change and in turn, how MBA students – as a proxy for emerging business leaders – perceive climate-related risks and opportunities. Results indicate that corporations are aligned in their focus on non-financial risks as a category but vary across industries on the importance and relevance of what constitutes ‘material’. MBA students place greater value on mitigating environmental and social disruption risk when primed of its importance but do not feel adequately prepared to address emergent social and environmental issues as corporate professionals.Item Open Access Fate of products of degradation processes: consequences for climatic change.(Chemosphere, 1999-03) Slanina, J; ten Brink, HM; Khlystov, AThe end products of atmospheric degradation are not only CO2 and H2O but also sulfate and nitrate depending on the chemical composition of the substances which are subject to degradation processes. Atmospheric degradation has thus a direct influence on the radiative balance of the earth not only due to formation of greenhouse gases but also of aerosols. Aerosols of a diameter of 0.1 to 2 micrometer, reflect short wave sunlight very efficiently leading to a radiative forcing which is estimated to be about -0.8 watt per m2 by IPCC. Aerosols also influence the radiative balance by way of cloud formation. If more aerosols are present, clouds are formed with more and smaller droplets and these clouds have a higher albedo and are more stable compared to clouds with larger droplets. Not only sulfate, but also nitrate and polar organic compounds, formed as intermediates in degradation processes, contribute to this direct and indirect aerosol effect. Estimates for the Netherlands indicate a direct effect of -4 watt m-2 and an indirect effect of as large as -5 watt m-2. About one third is caused by sulfates, one third by nitrates and last third by polar organic compounds. This large radiative forcing is obviously non-uniform and depends on local conditions.Item Open Access Filling the Ocean Funding Gap: A Study of Blended Finance and the Promise of Blue Bonds for Ocean Conservation(2024) Audino, MackenzieThe ocean covers 70% of the Earth’s surface, comprises 97% of all water on earth, and contains 99% of all living space on the planet. It plays a vital role in absorbing carbon dioxide and producing the oxygen we breathe, it is a significant component of the global economy, and a key element in fighting climate change. However, governments and organizations around the world continue to abuse the ocean rather than protect it. The past few years have seen numerous commitments to restoring and protecting the long-term health our oceans. Despite these commitments, the ocean remains chronically underfunded. This project analyzes the role that Blue Bonds can play in closing this funding gap and shows how Green Bonds can be used as a framework to scale the Blue Bond market. Additionally, I created an example bond, The Manta Bond, to illustrate the process by which blue bonds can support conservation goals.Item Open Access Heatwaves, medications, and heat-related hospitalization in older Medicare beneficiaries with chronic conditions.(PloS one, 2020-01) Layton, J Bradley; Li, Wenhong; Yuan, Jiacan; Gilman, Joshua P; Horton, Daniel B; Setoguchi, SokoBackground
Heatwaves kill more people than floods, tornadoes, and earthquakes combined and disproportionally affect older persons and those with chronic conditions. Commonly used medications for chronic conditions, e.g., diuretics, antipsychotics disrupt thermoregulation or fluid/electrolyte balance and may sensitive patients to heat. However, the effect of heat-sensitizing medications and their interactions with heatwaves are not well-quantified. We evaluated effects of potentially heat-sensitizing medications in vulnerable older patients.Methods
US Medicare data were linked at the zip code level to climate data with surface air temperatures for June-August of 2007-2012. Patients were Medicare beneficiaries aged ≥65 years with chronic conditions including diabetes, dementia, and cardiovascular, lung, or kidney disease. Exposures were potentially heat-sensitizing medications including diuretics, anticholinergics, antipsychotics, beta blockers, stimulants, and anti-hypertensives. A heatwave was defined as ≥2 days above the 95th percentile of historical zip code-specific surface air temperatures. We estimated associations of heat-sensitizing medications and heatwaves with heat-related hospitalization using self-controlled case series analysis.Results
We identified 9,721 patients with at least one chronic condition and heat-related hospitalization; 42.1% of these patients experienced a heatwave. Heatwaves were associated with an increase in heat-related hospitalizations ranging from 21% (95% CI: 7% to 38%) to 33% (95% CI: 14% to 55%) across medication classes. Several drug classes were associated with moderately elevated risk of heat-related hospitalization in the absence of heatwaves, with rate ratios ranging from 1.16 (95% CI: 1.00 to 1.35) to 1.37 (95% CI: 1.14 to 1.66). We did not observe meaningful synergistic interactions between heatwaves and medications.Conclusions
Older patients with chronic conditions may be at heightened risk for heat-related hospitalization due to the use of heat-sensitizing medications throughout the summer months, even in the absence of heatwaves. Further studies are needed to confirm these findings and also to understand the effect of milder and shorter heat exposure.Item Open Access Influence of Increased Human Presence in the Mills River Basin on Water Availability and Drought(2016) Hodes, JaredPeriods of drought and low streamflow can have profound impacts on both human and natural systems. People depend on a reliable source of water for numerous reasons including potable water supply and to produce economic value through agriculture or energy production. Aquatic ecosystems depend on water in addition to the economic benefits they provide to society through ecosystem services. Given that periods of low streamflow may become more extreme and frequent in the future, it is important to study the factors that control water availability during these times. In the absence of precipitation the slower hydrological response of groundwater systems will play an amplified role in water supply. Understanding the variability of the fraction of streamflow contribution from baseflow or groundwater during periods of drought provides insight into what future water availability may look like and how it can best be managed. The Mills River Basin in North Carolina is chosen as a case-study to test this understanding. First, obtaining a physically meaningful estimation of baseflow from USGS streamflow data via computerized hydrograph analysis techniques is carried out. Then applying a method of time series analysis including wavelet analysis can highlight signals of non-stationarity and evaluate the changes in variance required to better understand the natural variability of baseflow and low flows. In addition to natural variability, human influence must be taken into account in order to accurately assess how the combined system reacts to periods of low flow. Defining a combined demand that consists of both natural and human demand allows us to be more rigorous in assessing the level of sustainable use of a shared resource, in this case water. The analysis of baseflow variability can differ based on regional location and local hydrogeology, but it was found that baseflow varies from multiyear scales such as those associated with ENSO (3.5, 7 years) up to multi decadal time scales, but with most of the contributing variance coming from decadal or multiyear scales. It was also found that the behavior of baseflow and subsequently water availability depends a great deal on overall precipitation, the tracks of hurricanes or tropical storms and associated climate indices, as well as physiography and hydrogeology. Evaluating and utilizing the Duke Combined Hydrology Model (DCHM), reasonably accurate estimates of streamflow during periods of low flow were obtained in part due to the model’s ability to capture subsurface processes. Being able to accurately simulate streamflow levels and subsurface interactions during periods of drought can be very valuable to water suppliers, decision makers, and ultimately impact citizens. Knowledge of future droughts and periods of low flow in addition to tracking customer demand will allow for better management practices on the part of water suppliers such as knowing when they should withdraw more water during a surplus so that the level of stress on the system is minimized when there is not ample water supply.
Item Open Access Investigating the Eco-Hydrological Impact of Tropical Cyclones in the Southeastern United States(2013) Brun, JulienTropical Cyclones (TCs) intensity and frequency are expected to be impacted by climate change. Despite their destructive potential, these phenomena, which can produce heavy precipitation, are also an important source of freshwater. Therefore any change in frequency, seasonal timing and intensity of TCs is expected to strongly impact the regional water cycle and consequently the freshwater availability and distribution. This is critical, due to the fact that freshwater resources in the US are under stress due to the population growth and economic development that increasingly create more demands from agricultural, municipal and industrial uses, resulting in frequent over-allocation of water resources.
In this study we concentrate on monitoring the impact of hurricanes and tropical storms on vegetation activity along their terrestrial tracks and investigate the underlying physical processes. To characterize and monitor the spatial organization and time of recovery of vegetation disturbance in the aftermath of major hurricanes over the entire southeastern US, a remote sensed framework based on MODIS enhanced vegetation index (EVI) was developed. At the SE scale, this framework was complemented by a water balance approach to estimate the variability in hurricane groundwater recharge capacity spatially and between events. Then we investigate the contribution of TCs (season totals and event by event) to the SE US annual precipitation totals from 2002 to 2011. A water budget approach applied at the drainage basins scale is used to investigate the partitioning of TCs' precipitation into surface runoff and groundwater system in the direct aftermath of major TCs. This framework allows exploring the contribution of TCs to annual precipitation totals and the consequent recharge of groundwater reservoirs across different physiographic regions (mountains, coastal and alluvial plains) versus the fraction that is quickly evacuated through the river network and surface runoff.
Then a Land surface Eco-Hydrological Model (LEHM), combining water and energy budgets with photosynthesis activity, is used to estimate Gross Primary Production (GPP) over the SE US The obtained data is compared to AmeriFlux and MODIS GPP data over the SE United States in order to establish the model's ability to capture vegetation dynamics for the different biomes of the SE US. Then, a suite of numerical experiments is conducted to evaluate the impact of Tropical Cyclones (TCs) precipitation over the SE US. The numerical experiments consist of with and without TC precipitation simulations by replacing the signature of TC forcing by NARR-derived climatology of atmospheric forcing ahead of landfall during the TC terrestrial path. The comparison of these GPP estimates with those obtained with the normal forcing result in areas of discrepancies where the GPP was significantly modulated by TC activity. These areas show up to 10% variability over the last decade.