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The widespread demand for animal-sourced foods poses challenges in addressing climate change due to their significant greenhouse gas emissions. Alternative proteins like cultured meat show promise with lower greenhouse gas emissions, but have faced public resistance, posing substantial barriers to their broad development and adoption. This paper reports a survey that examined the perceived naturalness of protein sources as an important factor that predicts perceived risks, benefits, and support for consumption. A diverse sample from the United States considered six different protein technologies, including three newer alternative proteins such as cultured meat and three more conventional proteins. Newer alternative proteins were perceived as less natural and were less supported than conventional proteins. Additionally, the more participants perceived protein sources as natural, the less risky and more beneficial they perceived them to be, contributing to their support. These results suggest that perceived naturalness, and associated risks and benefits, could be an important factor in shaping public support for or opposition to new proteins. These findings have theoretical and broader implications for the development and adoption of sustainability technologies. [ABSTRACT FROM AUTHOR]

Attempts to clear the misinterpretation on the study done by Kirshen and Fennessey (KF) devoted to Climatic Change and Water Resources Planning Criteria. Water supply system of the Massachusetts Water Resources Authority; Total system demand of the KF study; Description on the KF scenario.

A recent paper in this journal argues that the choice of statistical model is responsible for the divergence in damage estimates of climate change on US agriculture. We provide five arguments why we believe this assertion is misguided. [ABSTRACT FROM AUTHOR]

How do we understand national climate change politics in the United States? Using a methodological innovation in network analysis, this paper analyzes discussions about the issue within the US Congress. Through this analysis, the ideological relationships among speakers providing Congressional testimony on the issue of climate change are mapped. For the first time, issue stances of actors are systematically aggregated in order to measure coalitions and consensus among political actors in American climate politics in a relational way. Our findings show how consensus formed around the economic implications of regulating greenhouse gases and the policy instrument that should do the regulating. The paper is separated into three sections. First, we review the ways scholars have looked at climate change policymaking in the United States, paying particular attention to those who have looked at the issue within the US Congress. Next, we present analysis of statements made during Congressional hearings on climate change over a four-year period. Our analysis demonstrates how a polarized ideological actor space in the 109 Congress transforms into a more consensual actor landscape in the 110 Congress, which is significantly less guided by partisan differences. This paper concludes by discussing how these findings help us understand shifting positions within American climate politics and the implications of these findings. [ABSTRACT FROM AUTHOR]

This paper projects the race between technologically driven increases in crop yields and changing climatic conditions in the central USA, one of the world's most productive agricultural regions. Using the highest, average, and lowest decadal rates of technologically driven increases in crop yields over the 1980 to 2017 period, we develop spatially explicit yield scenarios to the end of the twenty-first century under RCP4.5 and RCP8.5. We find that with static technological innovation, severe climate change will decrease yields by an average of 22.4% (26.1 bu. ac−1) for maize, 27.9% (8.83 bu. ac−1) for soybeans, and 20% (7.14 bu. ac−1) for winter wheat in the central USA; however, with even the lowest rates of technological yield growth, yields increase by an average of 25.0% (40.5 bu. ac−1) for maize and 30.2% (14.2 bu. ac−1) for soybeans. We conclude that technology has the potential to overcome the negative impacts of climate change on the yields of maize, soybeans, and winter wheat in the central USA, but if these increases are to be environmentally sustainable, technological developments must be information-intensive rather than input-intensive. [ABSTRACT FROM AUTHOR]

A number of knowledge gaps and research priorities emerged during the third US National Climate Assessment (NCA3). Several are also gaps in the latest IPCC WG2 report. These omissions reflect major gaps in the underlying research base from which these assessments draw. These include the challenge of estimating the costs and benefits of climate change impacts and responses to climate change and the need for research on climate impacts on important sectors such as manufacturing and services. Climate impacts also need to be assessed within an international context in an increasingly connected and globalized world. Climate change is being experienced not only through changes within a locality but also through the impacts of climate change in other regions connected through trade, prices, and commodity chains, migratory species, human mobility and networked communications. Also under-researched are the connections and tradeoffs between responses to climate change at or across different scales, especially between adaptation and mitigation or between climate responses and other environmental and social policies. This paper discusses some of these research priorities, illustrating their significance through analysis of economic and international connections and case studies of responses to climate change. It also critically reflects on the process of developing research needs as part of the assessment process. [ABSTRACT FROM AUTHOR]

Assessing regional-scale vulnerability of agricultural systems to climate change and variability is vital in securing food and fiber systems, as well as sustaining rural livelihoods. Farmers, ranchers, and forest landowners rely on science-based, decision-relevant, and localized information to maintain production, ecological viability, and economic returns. This paper synthesizes the collection of research on the future of agricultural production in the Southwestern United States. A variety of assessment methods indicate the diverse impacts and risks across the Southwest, often related to water availability, which drives adaptive measures in this region. Sector- or species-specific adaptive measures have long been practiced in this region and will continue to be necessary to support agricultural production as a regional enterprise. Diversification of crop selection and income source imparts climate resilience. Building upon biophysical vulnerability through incorporating social and economic factors is critical to future adaptation planning efforts. The persistence and adaptive capacity of agriculture in the water-limited Southwest serves as an instructive example for producers outside the region expecting drier and warmer conditions and may offer solutions to reduce future climate impacts. [ABSTRACT FROM AUTHOR]

The interior southwest United States is one of the hottest, driest regions on the planet, yet irrigated cropland agriculture is successfully practiced where there is access to surface water and/or groundwater. Through climate change, the southwest is projected to become even hotter and drier, increasing the challenges faced by farmers across the region. We can assess the vulnerability of cropland agriculture, to assist in developing potential solutions to these challenges of warming temperatures and water scarcity. However, these types of biophysical vulnerability assessment usually generate technological or policy-level solutions that do not necessarily account for farmers’ ability to respond to climate change impacts. Further, there are non-climatic factors that also threaten the future of agriculture in the region, such as population increase, loss of agricultural land, and increasing competition for depleting water resources. In this paper, we assert that to fully address how southwestern farmers may respond to climate change impacts, we must consider both biophysical outcome and contextual vulnerabilities. Future research on individual localities and/or specific commodities and including cross-disciplinary analysis of socio-economic, institutional, cultural, and political factors alongside biophysical factors will help to develop more substantive understanding of system vulnerabilities and feasible adaptive solutions. [ABSTRACT FROM AUTHOR]

The states of Colorado, Montana, Nebraska, North Dakota, South Dakota, and Wyoming comprise the Northern Great Plains region of the USA. The soil and water resources contained in this region have historically supported highly diverse and productive agriculture enterprises that provide a significant proportion of the food, feed, and oilseed for the nation. The region also provides ecological services that influence air, water, and soil quality along with biological diversity. Combined with livestock production and a biofuel industry, crop production forms an integrated system that can offer producers flexibility in management decisions. Projected climatic changes for this region include increasing atmospheric CO2, a longer, warmer growing season, and increased precipitation, likely received in more frequent extreme events. These changes will impact soil and water resources in the region and create opportunities and challenges for land managers. The objectives of this paper are to describe anticipated impacts of projected mid-(2050) and late-(2085) climatic changes on crop production systems in the Northern Great Plains and provide adaptation strategies that should be developed to take advantage of positive and mitigate negative changes. Projected climatic changes will influence agricultural productivity directly as well as indirectly due to changes in weed pressure, insect populations, and diseases. A warmer, longer growing season will change the crops and distribution of those crops grown within the region. An increase in the number of extreme temperature events (high daytime highs or nighttime lows) will decrease crop yields due to increased plant stress during critical pollination and grain fill periods. Adaptation strategies to reduce vulnerability of soil and water resources to projected climatic changes include increasing cropping intensity, reducing tillage intensity, and use of cover crops to provide surface cover to reduce erosion potential and improve nutrient and water use efficiency. Increased use of perennial forages, crop residue, and failed crops in integrated crop-livestock systems will add biological diversity and provide options for converting vegetation biomass into animal protein. Socio-economic changes will need to be incorporated into adaptation strategies planning to insure that sustaining ecosystem services and meeting desired production and conservation goals is accomplished. Education and extension services will be needed to transfer adaptive knowledge in a timely manner to producers in the field. [ABSTRACT FROM AUTHOR]

The average annual cost of floods in the United States has been estimated at about $2 billion (current US dollars). The federal government, through the creation of the National Flood Insurance Program (NFIP), has assumed responsibility for mitigating the societal and economic impacts of flooding by establishing a national policy that provides subsidized flood insurance. Increased flood costs during the past two decades have made the NFIP operate at a deficit. This paper argues that our current understanding of climate change and of the sensitivity of the urban environment to floods call for changes to the flood policy scheme. Conclusions are drawn on specific examples from cities along the heavily urbanized corridor of northeastern United States. Mesoscale and global models along with urbanization and economic growth statistics are used to provide insights and recommendations for future flood costs under different emissions scenarios. Mesoscale modeling and future projections from global models suggest, for example, that under a high emissions scenario, New York City could experience almost twice as many days of extreme precipitation that cause flood damage and are disruptive to business as today. The results of the paper suggest that annual flood costs in the United States will increase sharply by the end of the 21st Century, ranging from about $7 to $19 billion current US dollars, depending on the economic growth rate and the emissions scenarios. Hydrologic, hydraulic and other related uncertainties are addressed and a revised version of the NFIP is suggested. [ABSTRACT FROM AUTHOR]

This paper measures the influence of climate normals (average long-term surface wetness and temperature) and interannual climate variance on farms in the United States and Brazil using satellite data. The paper finds that just climate normals or just climate variance variables can explain both net revenues and how much land is used for cropland. However, because they are correlated with each other, it is important to include both normals and variance in the same statistical model to get accurate measures of their individual contribution to farm outcomes. In general, higher climate variance increases the probability that land is used for cropland in both countries and higher temperatures reduce both cropland and land values. Other annual effects were not consistent across the two countries. [ABSTRACT FROM AUTHOR]

If uncontrolled, human influences on the climate system may generate changes that will endanger various aspects of life on Earth. The precise implications of the scientific claims about climate change, and the extent to which they pose dangers to various populations, are becoming intensely debated at many levels in relation to policy. How 'danger' is interpreted will ultimately affect which actions are taken. In this paper, we examine how climate change is conceptualised by publics in Europe and in the USA. Although there is widespread concern about climate change, it is of secondary importance in comparison to other issues in people's daily lives. Most individuals relate to climate change through personal experience, knowledge, the balance of benefits and costs, and trust in other societal actors. We analyse these factors through findings from various surveys and studies, which highlight both the distinctiveness and some shared perspectives at a generalised level. We reflect upon these in relation to trust and responsibility for climate change action, and risk communication, supporting the call for discourses about climate change to also be situated in people's locality, as a means of increasing its saliency. [ABSTRACT FROM AUTHOR]

Abstract As carbon dioxide and other greenhouse gasses accumulate in the atmosphere and contribute to rising global temperatures, it is important to examine how a changing climate may affect natural and managed ecosystems. In this series of papers, we study the impacts of climate change on agriculture, water resources and natural ecosystems in the General Circulation Model (GCM)-derived climate change projections, described in Part 1, to drive the crop production and water resource models EPIC (Erosion Productivity Impact Calculator) and HUMUS (Hydrologic Unit Model of the United States). These models are described and validated in this paper using historical crop yields and streamflow data in the conterminous United States in order to establish their ability to accurately simulate historical crop and water conditions and their capability to simulate crop and water response to the extreme climate conditions predicted by GCMs. EPIC simulated grain and forage crop yields are compared with historical crop yields from the US Department of Agriculture (USDA) and with yields from agricultural experiments. EPIC crop yields correspond more closely with USDA historical county yields than with the higher yields from intensively managed agricultural experiments. The HUMUS model was validated by comparing the simulated water yield from each hydrologic basin with estimates of natural streamflow made by the US Geological Survey. This comparison shows that the model is able to reproduce significant observed relationships and capture major trends in water resources timing and distribution across the country. [ABSTRACT FROM AUTHOR]

The results of an experimental `end to end' assessment of the effects of climate change on water resources in the western United States are described. The assessment focuses on the potential effects of climate change over the first half of the 21st century on the Columbia, Sacramento/San Joaquin, and Colorado river basins. The paper describes the methodology used for the assessment, and it summarizes the principal findings of the study. The strengths and weaknesses of this study are discussed, and suggestions are made for improving future climate change assessments. [ABSTRACT FROM AUTHOR]

This paper applies city-specific mortality relationships for extremely hot and cold temperatures for 33 Metropolitan Statistical Areas in the United States to develop mortality projections for historical and potential future climates. These projections, which cover roughly 100 million of 310 million U.S. residents in 2010, highlight a potential change in health risks from uncontrolled climate change and the potential benefits of a greenhouse gas (GHG) mitigation policy. Our analysis reveals that projected mortality from extremely hot and cold days combined increases significantly over the 21st century because of the overwhelming increase in extremely hot days. We also find that the evaluated GHG mitigation policy could substantially reduce this risk. These results become more pronounced when accounting for projected population changes. These results challenge arguments that there could be a mortality benefit attributable to changes in extreme temperatures from future warming. This finding of a net increase in mortality also holds in an analog city sensitivity analysis that incorporates a strong adaptation assumption. While our results do not address all sources of uncertainty, their scale and scope highlight one component of the potential health risks of unmitigated climate change impacts on extreme temperatures and draw attention to the need to continue to refine analytical tools and methods for this type of analysis. [ABSTRACT FROM AUTHOR]

An introduction is presented in which the authors present an overview of the special issue regarding the use of a multi-model framework in the Climate Change Impacts and Risk Analysis (CIRA) project in the U.S.

With rising sea levels and possible storm intensification due to climate change, current United States urban coastal flood management strategies will be challenged. Due to limitations of current flood management strategies, evacuation is likely to become increasingly prominent in many coastal areas. Thus it is important to think critically about challenges for successful evacuation planning, particularly for vulnerable communities. This paper brings together the evacuation planning, climate change and environmental justice literatures. We describe the unique challenges that environmental justice communities face with evacuation, and identify best practice guidelines to improve the quality of evacuation planning for these communities. The guidelines presented, while not comprehensive, provide a framework for planners and policymakers to consider when developing evacuation plans, both for current and future climate conditions, and could improve the quality of evacuation planning. [ABSTRACT FROM AUTHOR]

Many studies suggest that warming is harmful to American crop yields because of a temperature threshold near 30 °C whereupon yields abruptly fall. This study uses a flexible daily temperature bin specification in a Ricardian model to measure the response of farmland value to daily temperature. The analysis does not find evidence that high temperatures are particularly harmful to farmland or cropland value in the Eastern United States. Instead, temperature has a smooth hill-shaped effect on farmland value with a peak temperature of about 18 °C. Nonetheless, the Ricardian model predicts that cropland values would fall linearly by 15%/°C with uniform warming, while farmland values of mixed farms would fall far less. [ABSTRACT FROM AUTHOR]

This paper argues that the IPCC has oversimplified the issue of uncertainty in its Assessment Reports, which can lead to misleading overconfidence. A concerted effort by the IPCC is needed to identify better ways of framing the climate change problem, explore and characterize uncertainty, reason about uncertainty in the context of evidence-based logical hierarchies, and eliminate bias from the consensus building process itself. [ABSTRACT FROM AUTHOR]

Lodgepole pine ( Pinus contorta Dougl.) is a widely distributed species in the Pacific Northwest of North America. The extent that the current distribution of this species may be altered under a changing climate is an important question for managers of wood supply as well as those interested in conservation of subalpine ecosystems. In this paper, we address the question, how much might the current range of the species shift under a changing climate? We first assessed the extent that suboptimal temperature, frost, drought, and humidity deficits affect photosynthesis and growth of the species across the Pacific Northwest with a process-based model (3-PG). We then entered the same set of climatic variables into a decision-tree model, which creates a suite of rules that differentially rank the variables, to provide a basis for predicting presence or absence of the species under current climatic conditions. The derived decision-tree model successfully predicted weighted presence and absence recorded on 12,660 field survey plots with an accuracy of ~70%. The analysis indicated that sites with significant spring frost, summer temperatures averaging <15°C and soils that fully recharged from snowmelt were most likely to support lodgepole pine. Based on these criteria, we projected climatic conditions through the twenty-first century as they might develop without additional efforts to reduce carbon emissions using the Canadian Climate Centre model (CGCM2). In the 30-year period centered around 2020, the area suitable for lodgepole pine in the Pacific Northwest was projected to be reduced only slightly (8%). Thereafter, however, the projected climatic conditions appear to progressively favor other species, so that by the last 30 years of twenty-first century, lodgepole pine could be nearly absent from much of its current range. We conclude that process-based models, because they are highly sensitive to seasonal variation in solar radiation, are well adapted to identify the importance of different climatic variables on photosynthesis and growth. These same variables, once indentified, and run through a decision-tree model, provide a reasonable approach to predict current and future patterns in a species' distribution. [ABSTRACT FROM AUTHOR]

The first part of the paper demonstrates the connection between the abolition of slavery and the Industrial Revolution: steam power changed the perception of labour; new techniques facilitated diffusion of pro-abolition pamphlets; fewer threats to basic existence resulting from industrial advances fostered sensibilities and moral standards toward abolitionism; and, through industrial development, the North grasped victory in the American Civil War. The second part presents similarities between societies in the past that have used slave labour and those in the present that use fossil fuels. It argues that slaves and fossil-fuelled machines play(ed) similar economic and social roles: both slave societies and developed countries externalise(d) labour and both slaves and modern machines free(d) their owners from daily chores. Consequently, we are as dependent on fossil fuels as slave societies were dependent on bonded labour. It also suggests that, in differing ways, suffering resulting (directly) from slavery and (indirectly) from the excessive burning of fossil fuels are now morally comparable. When we emit carbon dioxide at a rate that exceeds what the ecosystem can absorb, when we deplete non-renewable resources, we indirectly cause suffering to other human beings. Similarly, cheap oil facilitates imports of goods from countries with little social protection and hence help externalise oppression. The conclusion draws on the lessons which may be learned by Climate Change campaigners from the campaigns to abolish slavery: environmental apathy can be opposed effectively if we learn from what worked in the fight against this inhuman institution. [ABSTRACT FROM AUTHOR]

Article 2 of the United Nations Framework Convention on Climate Change commits its parties to stabilizing greenhouse gas concentrations in the atmosphere at a level that “would prevent dangerous anthropogenic interference with the climate system.” Authors of the Third Assessment Report of the Intergovernmental Panel on Climate Change (IPCC , ) offered some insight into what negotiators might consider dangerous by highlighting five “reasons for concern” (RFC’s) and tracking concern against changes in global mean temperature; they illustrated their assessments in the now iconic “burning embers” diagram. The Fourth Assessment Report reaffirmed the value of plotting RFC’s against temperature change (IPCC , ), and Smith et al. () produced an unpated embers visualization for the globe. This paper applies the same assessment and communication strategies to calibrate the comparable RFC’s for the United States. It adds “National Security Concern” as a sixth RFC because many now see changes in the intensity and/or frequency of extreme events around the world as “risk enhancers” that deserve attention at the highest levels of the US policy and research communities. The US embers portrayed here suggest that: (1) US policy-makers will not discover anything really “dangerous” over the near to medium term if they consider only economic impacts that are aggregated across the entire country but that (2) they could easily uncover “dangerous anthropogenic interference with the climate system” by focusing their attention on changes in the intensities, frequencies, and regional distributions of extreme weather events driven by climate change. [ABSTRACT FROM AUTHOR]

This paper deals with different responses from various Atmosphere-Ocean Global Climate Models (AOGCMs) at the regional scale. What can be the best use of AOGCMs for assessing the climate change in a particular region? The question is complicated by the consideration of intra-year month-to-month variability of a particular climate variable such as precipitation or temperature in a specific region. A maximum entropy method (MEM), which combines limited information with empirical perspectives, is applied to assessing the probability-weighted multimodel ensemble average of a climate variable at the region scale. The method is compared to and coupled with other two methods: the root mean square error minimization method and the simple multimodel ensemble average method. A mechanism is developed to handle a comprehensive range of model uncertainties and to identify the best combination of AOGCMs based on a balance of two rules: depending equally on all models versus giving higher priority to models more strongly verified by the historical observation. As a case study, the method is applied to a central US region to compute the probability-based average changes in monthly precipitation and temperature projected for 2055, based on outputs from a set of AOGCMs. Using the AOGCM data prepared by international climate change study groups and local climate observation data, one can apply the MEM to precipitation or temperature for a particular region to generate an annual cycle, which includes the effects from both global climate change and local intra-year climate variability. [ABSTRACT FROM AUTHOR]

This paper explores the paradox that while Americans generally identify themselves as environmentalists, they show little willingness to voluntarily restrain their behavior or to support specific fiscal policies that would result in increased levels of environmental protection. I explore the role of values in the explanation of this paradox, and discuss some of the difficulties involved in studying values and their role in human behavior. [ABSTRACT FROM AUTHOR]

Abstract This special issue of Climatic Change describes an effort to improve methodology for integrated assessment of impacts and consequences of climatic change. Highlights of the seven foregoing Parts (papers) that constitute this special issue are summarized here. The methodology developed involves construction of scenarios of climate change that are used to drive individual sectoral models for simulating impacts on crop production, irrigation demand, water supply and change in productivity and geography of unmanaged ecosystems. Economic impacts of the changes predicted by integrating the results of the several sectoral simulation models are calculated through an agricultural land-use model. While these analyses were conducted for the conterminous United States alone, their global implications are also considered in this summary as is the need for further improvements in integrated assessment methodology. [ABSTRACT FROM AUTHOR]

Abstract During this century global warming will lead to changes in global weather and climate, affecting many aspects of our environment. Agriculture is the sector of the United States economy most likely to be directly impacted by climatic changes. We have examined potential changes in dryland agriculture (Part 3) and in water resources necessary for crop production (Part 4) in response to a set of climate change scenarios. In this paper we assess to what extent, under these same scenarios, water supplies will be sufficient to meet the irrigation requirement of major grain crops in the US. In addition, we assess the overall impacts of changes in water supply on national grain production. We apply the 12 climate change scenarios described in Part 1 to the water resources and crop growth simulation models described in Part 2 for the conterminous United States. Drawing on data from Parts 3 and 4 we calculate what the aggregate national production would be in those regions in which grain crops are currently produced by applying irrigation where needed and water supplies allow. The total amount of irrigation water applied to crops declines under all climate change scenarios employed in this study. Under certain of the scenarios and in particular regions, precipitation decreases so much that water supplies are too limited; in other regions precipitation becomes so plentiful that little value is derived from irrigation. Nationwide grain crop production is greater when irrigation is applied as needed. Under irrigation, less corn and soybeans are produced under most of the climate change scenarios than is produced under baseline climate conditions. Winter wheat production under irrigation responds significantly to elevated atmospheric carbon dioxide concentrations [CO2] and appears likely to increase under climate change. [ABSTRACT FROM AUTHOR]

One of the issues with respect to climate change involves its influence on the distribution of future crop yields. Many studies have been done regarding the effect on the mean of such distributions but few have addressed the effect on variance. Furthermore, those that have been done generally report the variance from crop simulators, not from observations. This paper examines the potential effects of climate change on crop yield variance in the context of current observed yields and then extrapolates to the effects under projected climate change. In particular, maximum likelihood panel data estimates of the impacts of climate on year-to-year yield variability are constructed for the major U.S. agricultural crops. The panel data technique used embodies a variance estimate developed along the lines of the stochastic production function approach suggested by Just and Pope. The estimation results indicate that changes in climate modify crop yield levels and variances in a crop-specific fashion. For sorghum, rainfall and temperature increases are found to increase yield level and variability. On the other hand, precipitation and temperature are individually found to have opposite effects on corn yield levels and variability. [ABSTRACT FROM AUTHOR]

The purpose of the paper is to propose and test a new approach to simulating farmers' agronomic adaptation to climate change based on the pattern of adoption of technological innovation/substitution over time widely described as a S-shaped (or logistic) curve, i.e., slow growth at the beginning followed by accelerating and then decelerating growth, ultimately leading to saturation. The approach we developed is tested using the Erosion Productivity Impact Calculator crop model applied to corn production systems in the southeastern U.S. using a high-resolution climate change scenario. Corn is the most extensively grown crop in the southeastern U.S. The RegCM limited area model nested within the CSIRO general circulation model generated the scenario. We compare corn yield outcomes using this new form of adaptation (logistic) with climatically optimized (clairvoyant) adaptation. The results show logistic adaptation to be less effective than clairvoyant adaptation in ameliorating climate change impacts on yields, although the differences between the two sets of yields are statistically significant in one case only. These results are limited by the reliance on a single scenario of climate change. We conclude that the logistic technique should be tested widely across climate change scenarios, crop species, and geographic areas before a full evaluation of its effect on outcomes is possible. [ABSTRACT FROM AUTHOR]

This study explores sense-making about climate engineering among lay focus group participants in Japan, New Zealand, the USA and Sweden. In total, 23 qualitative focus group interviews of 136 participants were conducted. The analyses considered sense-making strategies and heuristics among the focus group participants and identified commonalities and variations in the data, exploring participants' initial and spontaneous reactions to climate engineering and to several recurrent arguments that feature in scientific and public debate (e.g. climate emergency). We found that, despite this study's wide geographical scope, heterogeneous focus group compositions, and the use of different moderators, common themes emerged. Participants made sense of climate engineering in similar ways, for example, through context-dependent analogies and metaphorical descriptions. With few exceptions, participants largely expressed negative views of large-scale deliberate intervention in climate systems as a means to address anthropogenic global warming. [ABSTRACT FROM AUTHOR]

Comments on the issues raised by Paul Kirshen on a particular comparison made of contrasting results in studies of climate sensitivity of the Boston, Massachusetts area Metropolitan Water Supply System to global warming. Error in simulations; Error in the Kirshen and Fennessey study; Corrected version of the model.

Human activities in the Arctic are often mentioned as recipients of climate-change impacts. In this paper we consider the more complicated but more likely possibility that human activities themselves can interact with climate or environmental change in ways that either mitigate or exacerbate the human impacts. Although human activities in the Arctic are generally assumed to be modest, our analysis suggests that those activities may have larger influences on the arctic system than previously thought. Moreover, human influences could increase substantially in the near future. First, we illustrate how past human activities in the Arctic have combined with climatic variations to alter biophysical systems upon which fisheries and livestock depend. Second, we describe how current and future human activities could precipitate or affect the timing of major transitions in the arctic system. Past and future analyses both point to ways in which human activities in the Arctic can substantially influence the trajectory of arctic system change. [ABSTRACT FROM AUTHOR]

Abstract PNNLs Agriculture and Land Use is used to demonstrate the impact of potential changes in climate on agricultural production and land use in the United States. AgLU simulates production of four crop types in several world regions, in 15-yr time steps from 1990 to 2095. Changes in yield of major field crops in the United States, for 12 climate scenarios, are obtained from simulations of the EPIC crop growth model. Results from the HUMUS model are used to constrain crop irrigation, and BIOME3 model is used to simulate productivity of unmanaged ecosystems. Assumptions about changes in agricultural productivity outside the United States are treated on a scenario basis, either responding in the same way as in the United States, or not responding to climate. [ABSTRACT FROM AUTHOR]

We examine the effect of climate scenarios generated using results from climate models of different spatial resolution on yields simulated by the deterministic cotton model GOSSYM for the southeastern U.S.A. Two related climate change scenarios were used: a coarse-scale scenario produced from results of a general circulation model (GCM) which also provided the boundary conditions to a regional climate model (RCM), from which a fine-scale scenario was constructed. Cotton model simulations were performed for three cases: climate change alone; climate change and elevated CO2; climate change, elevated CO2 and adaptations to climate change. In general, significant differences in state-average projected yield changes between the coarse and fine-scale scenarios are found for these three cases. In the first two cases, different directions of change are found in some sub-regions. With adaptation, yields substantially increase for both climate scenarios, but more so for the coarse-scale scenario (30% domain-average increase). Under irrigation, yield change differences between the two climate scenarios are small in all three cases, and yields are higher under irrigation (~ 35% domain-average increase with adaptation case) compared to dryland conditions. For the climate change alone case, differences in summer water-stress levels explain the contrasts in dryland yield patterns between the coarse and fine-scale climate scenarios. [ABSTRACT FROM AUTHOR]

Presents information on a study that uses empirical agricultural impact models to compare the United States climate change predictions of 16 General Circulation Models (GCM). Policy-relevant index provided by the impact analysis; Why the national aggregate impacts vary widely across the 16 GCM; Climate predictions; Methodology; Conclusions.

Numerous studies to date have interrogated United States (US) think tanks—and their networks—involved in climate change countermovement (CCM). Comparatively in Europe (EU), research has been lacking. This investigation therefore attends to that gap. We conducted a frame analysis on eight most prominent contrarian think tanks in six countries and four languages in Europe over 24 years (1994–2018). We found that there has been consistent contrarian framing through think tanks in the EU regarding climate change. Yet, we found a proliferation of contrarian outputs particularly in recent years. This uptick in quantity correlates with increases in CCM activities in the US. Our content analyses showed that well-worn climate change counter-frames spread by US CCM organizations were consistently circulated by European organizations as well. Moreover, we found that, as in the US, neoliberal ideological stances stood out as the most frequently taken up by contrarian think tanks in Europe. As such, we documented that CCM tropes and activities have flowed strongly between US and EU countries. [ABSTRACT FROM AUTHOR]

Local communities around the world are directly exposed to impacts of climate change. It is also clear that many local governments are politically and economically constrained in their capacity to implement needed adaptations. These constraints can restrict adaptation options to incremental, or even maladaptive, practices. At the same time, necessary transformational actions may remain out of reach for local actors. Building on five years of collaborative research with the city of Flagler Beach (FL, USA), we draw on political process theories to describe how incremental adaptation activities that are possible within current constraints can serve to build local capacity for instigating reforms at higher scales of social organization. We use the concept of a collective action strategy to conceptualize how context-specific barriers to adaptation can be overcome. From our analysis, an idealized multi-step process for designing collective action strategies is presented. The study advances scholarship on limits to adaptation beyond the diagnosis of barriers to action by taking steps towards developing context-specific strategies for overcoming these barriers. [ABSTRACT FROM AUTHOR]

Climate data obtained from global climate models (GCMs) form the basis of most studies of regional climate change and its impacts. Using the northeastern U.S. as a test case, we develop a framework to systematically sub-select reliable models for use in climate change studies in the region. Model performance over the historical period is evaluated first for a wide variety of standard and process metrics including large-scale atmospheric circulation features that drive regional climate variability. The inclusion of process-based metrics allows identification of credible models in capturing key processes relevant for the climate of the northeastern U.S. Model performance is then used in conjunction with the assessment of redundancy in model projections, especially in summer precipitation, to eliminate models that have better performing counterparts. Finally, we retain some mixed-performing models to maintain the range of climate model uncertainty, required by the fact that model biases are not strongly related to their respective projections. This framework leads to the retention of 16 of 36 CMIP5 GCMs that (a) have a satisfactory historical performance for a variety of metrics and (b) provide diverse climate projections consistent with uncertainties in the multi-model ensemble (MME). Overall, the models show significant variations in their performance across metrics and seasons with none emerging as the best model in all metrics. The retained set reduces the number of models by more than one half, easing the computational burden of using the entire CMIP5 MME, while still maintaining a wide range of projections for risk assessment. The retention of some mixed-performing models to maintain ensemble uncertainty suggests a potential to narrow the ranges in temperature and precipitation. But any further refinement should be based on a more detailed analysis of models in capturing regional climate variability and extremes to avoid providing overconfident projections. [ABSTRACT FROM AUTHOR]

Cities in the USA engage in action on climate change, even as the federal government remains resistant to comprehensive climate policy. While experts generally agree that local level adaptation and mitigation policies are critical to avoiding the worst climate impacts, the degree to which cities communicate climate change issues to their constituents has yet to be fully explored. In this article, we evaluate how US cities communicate climate change-related issues, problems, and policies. We use a computer-assisted approach to evaluate climate change efforts by cities by examining the full text of press releases of 82 large cities in the USA. We first identify who discusses climate change, finding that many large cities in the USA address climate change in their public communication. Second, we examine the content of these discussions. Many cities discuss weather-related concerns in conjunction with broad collaborative efforts to address global warming, while city-based policy discussions focus more on energy and transportation efforts. Third, we evaluate the local factors associated with these discussions. We find that the city’s climate vulnerability is particularly influential in shaping the level and timing of climatic communication. [ABSTRACT FROM AUTHOR]

Climate change effects are already apparent in some Southwestern US forests and are expected to intensify in the coming decades, via direct (temperature, precipitation) and indirect (fire, pests, pathogens) stressors. We grouped Southwestern forests into ten major types to assess their climate exposure by 2070 using two global climate models (GCMs) and two emission scenarios representing wetter or drier conditions and current or lowered emission levels. We estimate future climate exposure over forests covering 370,144 km2 as the location and proportion of each type projected to experience climate conditions that fall outside 99% of those they currently occupy. By late century, 27-77% is climatically exposed under wetter or drier current emission levels, while lowered emission levels produce 10-50% exposure, respectively. This difference points to the benefits of reducing emissions from the RCP8.5 to the RCP4.5 track, with regard to forest retention. Exposed areas common to all four climate futures include central Arizona and the western slope of the Sierra Nevada. Vulnerability assessments also comprise sensitivity and adaptive capacity, which we scored subjectively by forest type according to the number of key stressors they are sensitive to and the resilience conferred by life history traits of their dominant tree species. Under the 2070 RCP8.5 emissions, four forest types are critically and six are highly vulnerable under the hotter GCM; and eight are highly and two moderately vulnerable under the wetter GCM. We discuss forest management adaptation strategies and the barriers to and co-benefits of such plans. [ABSTRACT FROM AUTHOR]

The Southwestern US is a five-state region that has supported animal agriculture since the late 16th Century when European settlers crossed the Rio Grande into present day west Texas and southern New Mexico with herds of cattle, sheep, goats and horses. For the past 400 years the rangeland livestock industry, in its many forms and manifestations, has developed management strategies and conservation practices that impart resilience to the climatic extremes, especially prolonged droughts, that are common and extensive across this region. Livestock production from rangelands in the southwest (SW) is adapted to low rainfall and high ambient temperatures, but will have to continue to adapt management strategies, such as reduced stocking rates, proper grazing management practices, employing animal genetics suited to arid environments with less herbaceous production, erosion control conservation practices, and alternative forage supplies, in an increasingly arid and variable climatic environment. Even though the aging demographics of western ranchers could be a deterrent to implementing various adaptations, there are examples of creative management coalitions to cope with climatic change that are emerging in the SW that can serve as instructive examples. More importantly, there are additional opportunities for incorporation of transformative practices and technologies that can sustain animal agriculture in the SW in a warmer environment. Animal agriculture in the SW is inherently resilient, and has the capacity to adapt and transform as needed to the climatic changes that are now occurring and will continue to occur across this region. However, producers and land managers will need to thoroughly understand the vulnerabilities and sensitivities that face them as well as the ecological characteristics of their specific landscapes in order to cope with the emerging climatic changes across the SW region. [ABSTRACT FROM AUTHOR]

Native and agricultural forests in the Northern Plains provide ecosystem services that benefit human society—diversified agricultural systems, forest-based products, and rural vitality. The impacts of recent trends in temperature and disturbances are impairing the delivery of these services. Climate change projections identify future stressors of greater impact, placing at risk crops, soils, livestock, biodiversity, and agricultural and forest-based livelihoods. While these native and agricultural forests are also a viable option for providing mitigation and adaptation services to the Northern Plains, they themselves must be managed in terms of climate change risks. Because agricultural forests are planted systems, the primary approaches for reducing risks are through design, plant selection and management. For native forests, management, natural disturbances, and collaboration of multiple ownerships will be needed to address key risks. [ABSTRACT FROM AUTHOR]

We examine the impacts of climate on net returns from crop and livestock production and the resulting impact on land-use change across the contiguous USA. We first estimate an econometric model to project effects of weather fluctuations on crop and livestock net returns and then use a semi-reduced form land-use share model to study agricultural land-use changes under future climate and socio-economic scenarios. Estimation results show that crop net returns are more sensitive to thermal and less sensitive to moisture variability than livestock net returns; other agricultural land uses substitute cropland use when 30-year averaged degree-days or precipitation are not beneficial for crop production. Under future climate and socio-economic scenarios, we project that crop and livestock net returns are both increasing, but with crop net returns increasing at a higher rate; cropland increases with declines of marginal and pastureland by the end of the twenty-first century. Projections also show that impacts of future climate on agricultural land uses are substantially different and a larger variation of land-use change is evident when socio-economic scenarios are incorporated into the climate impact analysis. [ABSTRACT FROM AUTHOR]

This study presents an initial exploration of newspapers' visual representations of climate change using a construal-level perspective. We measured the level of abstraction of 635 news images from widely circulated US newspapers using a novel and replicable coding scheme which we derived from existing construal level literature and communication research. The results show, contrary to expectations, that climate change has been visually portrayed as a relatively concrete rather than abstract issue and has been mostly portrayed with a high level of specificity. In particular, USA Today visually covered the issue as most concrete, followed by the New York Times and Wall Street Journal. Human-themed images were the most concrete images as compared to nature-themed and industry-themed images. Findings regarding the level of abstraction of news images, though not necessarily representing audiences' perceptions, clearly indicate that construal level aspects in the news images provide another novel way of understanding and interpreting climate change imagery in the US media. [ABSTRACT FROM AUTHOR]

El Niño, the Indian Ocean Dipole (IOD), and the Tropical North Atlantic variability (TNA) can influence southeastern South America (SESA) rainfall, particularly during springtime. A recent study has shown that during the last century, there were two synchronization periods (1930s and 1970s) in which different tropical oceans interacted among themselves and, in turn, induced precipitation anomalies over SESA. In this study, we evaluate how this collective influence of the tropical oceans on SESA precipitation observed during the twentieth century, can change in the next century as result of anthropogenic forcing. To do so, we use the output of seven different CMIP5 models and construct a network using as nodes the indices of the Niño3.4, the TNA, the IOD and rainfall over SESA. After evaluating their skill in representing the observed network statistics during the twentieth century, we study changes in the network under RCP4.5 and 8.5 global warming scenarios in the twenty-first century. Focusing on the grand CMIP5 ensemble mean, results suggest that an anthropogenic forcing would increase the number of synchronization periods per century, their time length, and the connectivity between nodes (with the exception of TNA and IOD in RCP8.5). The stronger connectivity of SESA precipitation with the tropical oceans in both scenarios suggest an increase of the oceanic influence on rainfall over SESA as a result of anthropogenic forcing, which would enhance its seasonal predictability. However, these results have to be taken with caution because there is a large disparity in model behavior and thus a large uncertainty in conclusions suggested from the grand ensemble mean. [ABSTRACT FROM AUTHOR]

This study projects land cover probabilities under climate change for corn (maize), soybeans, spring and winter wheat, winter wheat-soybean double cropping, cotton, grassland and forest across 16 central U.S. states at a high spatial resolution (see ), while also taking into account the influence of soil characteristics and topography. The scenarios span three coupled climate models, three Representative Concentration Pathways (RCPs), and three time periods (2040, 2070, 2100). As climate change intensifies, the suitable area for all six crops display large northward shifts. Total suitable area within the study area for spring wheat, followed by corn and soybeans, diminish. Suitable area for winter wheat and for winter wheat-soybean double-cropping expand northward, while cotton suitability migrates to new, more northerly, locations. Grassland intensifies in the western Great Plains as crop suitability diminishes; suitability for forest intensifies in the south while yielding to crops in the north. To maintain current broad geographic patterns of land use, large changes in the thermal response of crops such as corn would be required. A transition from corn-soybean rotations to winter wheat-soybean doubling cropping is an alternative adaptation. [ABSTRACT FROM AUTHOR]

Localized vulnerability assessments are critical to effective climate adaptation. However, the differences between how local decision-makers and experts see vulnerability have not yet been fully explored, especially in the United States. Seeing possible distinctions between these approaches is critical since it is necessary to ensure a comprehensive, accountable approach. This research explores the distinct approach of local stakeholders to conceptualizing climate vulnerability in six American cities. Sixty-five interviews of cross-sectoral local stakeholders were conducted in: Boston (MA), Los Angeles (CA), Portland (OR), Raleigh (NC), and Tampa (FL). Findings demonstrate that conceptualizations of vulnerability are affected by intellectual frameworks that tend to orient around infrastructure and human health; that retrospective and prospective thinking are inter-related and affect one another; and that institutionalized forms and biases are critical. These factors shape the way that vulnerability is conceived differently than traditional expert frameworks. [ABSTRACT FROM AUTHOR]

Wildfire can impose a direct impact on human health under climate change. While the potential impacts of climate change on wildfires and resulting air pollution have been studied, it is not known who will be most affected by the growing threat of wildfires. Identifying communities that will be most affected will inform development of fire management strategies and disaster preparedness programs. We estimate levels of fine particulate matter (PM) directly attributable to wildfires in 561 western US counties during fire seasons for the present-day (2004-2009) and future (2046-2051), using a fire prediction model and GEOS-Chem, a 3-D global chemical transport model. Future estimates are obtained under a scenario of moderately increasing greenhouse gases by mid-century. We create a new term 'Smoke Wave,' defined as ≥2 consecutive days with high wildfire-specific PM, to describe episodes of high air pollution from wildfires. We develop an interactive map to demonstrate the counties likely to suffer from future high wildfire pollution events. For 2004-2009, on days exceeding regulatory PM standards, wildfires contributed an average of 71.3 % of total PM. Under future climate change, we estimate that more than 82 million individuals will experience a 57 % and 31 % increase in the frequency and intensity, respectively, of Smoke Waves. Northern California, Western Oregon and the Great Plains are likely to suffer the highest exposure to widlfire smoke in the future. Results point to the potential health impacts of increasing wildfire activity on large numbers of people in a warming climate and the need to establish or modify US wildfire management and evacuation programs in high-risk regions. The study also adds to the growing literature arguing that extreme events in a changing climate could have significant consequences for human health. [ABSTRACT FROM AUTHOR]

Many recent changes in tree species distributions, mortality, and growth rates have been linked to changes in climate. Managing forests in the face of climate change will require a basic understanding of which tree species will be most vulnerable to climate change and in what ways they will be vulnerable. We assessed the relative vulnerability to climate change of 11 tree species in western North America using a multivariate approach to quantify elements of sensitivity to climate change, exposure to climate change, and the capacity to adapt to climate change. Our assessment was based on a combination of expert knowledge, published studies, and projected changes in climate. Of the 11 species, Garry oak ( Quercus garryana) was determined to be the most vulnerable, largely because of its relatively high sensitivity. Garry oak occupies some of the driest low woodland and savanna sites from British Columbia to California and is highly dependent on disturbances, such as periodic, low intensity fire. Big leaf maple ( Acer macrophyllum) was determined to be the least vulnerable, largely because of its adaptive capacity. Big leaf maple can reproduce quickly after disturbances and its seeds can disperse long distances potentially allowing it to move in response to a changing climate. Our analyses provide a framework for assessing vulnerability and for determining why some species will likely be more vulnerable than others. Such information will be critical as natural resource managers and conservation practitioners strive to address the impacts of climate change with limited funds. [ABSTRACT FROM AUTHOR]

We examine trends and variability in low flows over the eastern U.S. (S. Carolina to Maine) and their attribution in a changing climate. We select 149 out of 4878 USGS stations over the eastern U.S., taking into account data availability and minimal direct management. Annual 7-day low flows (Q7) are computed from the series of daily streamflow records for 1962-2011 and compared to an antecedent precipitation (AP) index calculated over the corresponding basin for each station. In general, a north-south (increasing-decreasing) dipole pattern in low flow trends is associated with trends in AP. The exception is in the southern part of the study area including Virginia and the Carolinas, where moderate increasing trends in AP may have been offset by water withdrawals and increasing potential evapotranspiration (PET) as driven by increasing temperature and vapor pressure deficit. A principal component analysis (PCA) of Q7 and AP indicates that the North Atlantic Oscillation (NAO) and Pacific North America (PNA) pattern show statistically significant correlations for Q7 at 1 and 2 month lead time, respectively, via large-scale pressure patterns. Our findings suggest that the inter-annual variability of low flows has increased due to significant anti-correlation between the NAO and PNA during recent decades, and the future risk of low flow extremes may be further enhanced with temperature driven increases in PET and persistence of the multi-decadal relationship between NAO and PNA. [ABSTRACT FROM AUTHOR]

In this study, we analyze changes in extreme temperature and precipitation over the US in a 60-member ensemble simulation of the 21st century with the Massachusetts Institute of Technology (MIT) Integrated Global System Model-Community Atmosphere Model (IGSM-CAM). Four values of climate sensitivity, three emissions scenarios and five initial conditions are considered. The results show a general intensification and an increase in the frequency of extreme hot temperatures and extreme precipitation events over most of the US. Extreme cold temperatures are projected to decrease in intensity and frequency, especially over the northern parts of the US. This study displays a wide range of future changes in extreme events in the US, even simulated by a single climate model. Results clearly show that the choice of policy is the largest source of uncertainty in the magnitude of the changes. The impact of the climate sensitivity is largest for the unconstrained emissions scenario and the implementation of a stabilization scenario drastically reduces the changes in extremes, even for the highest climate sensitivity considered. Finally, simulations with different initial conditions show conspicuously different patterns and magnitudes of changes in extreme events, underlining the role of natural variability in projections of changes in extreme events. [ABSTRACT FROM AUTHOR]