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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.

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]

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]

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]

The paper focuses on relocation, retreat, zoning, insurance, and subsidy as major dimensions of coastal hazard mitigation measures that have resurfaced as potent forces for combating coastal inundation and climate change. It reviews the issues surrounding the practice of these measures and discusses compatibilities of policies, engineering measures, and natural defense. Property rights, development interest, and distorted financial incentives pose as main barriers to coastal relocation and retreat policies in hazard-prone areas. To understand and propose coastal adaptation solutions, the paper recommends place-based studies of local coastal adaptation strategies. Place-based studies offer an in-depth knowledge of local conditions specifically regarding the level of implementation of hazard mitigation policies, and shed light on important trade-offs and synergies of various hazard policies. In addition, coupling existing hazard mitigation policies with coastal management and community management can better inform long-term and comprehensive planning of coastal adaptation. [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]

The article presents the author's perspectives on the two papers published in the 2009 issue of the publication "Climatic Change Letters." He notes that the two letters emphasized the great cost involved in strictly adhering to the greenhouse gas mitigation-oriented Byrd-Hagel Resolution from U.S. He discusses the implications of the integrated assessment models used by the papers, in intensifying the commitment of various countries especially China in reducing the emission.

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]

Abstract As carbon dioxide and other greenhouse gases accumulate in the atmosphere and contribute to rising global temperatures, it is important to examine how derivative changes in 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 conterminous United States using twelve scenarios derived from General Circulation Model (GCM) projections to drive biophysical impact models. These scenarios are described in this paper. The scenarios are first put into the context of recent work on climate-change by the IPCC for the 21st century and span two levels of global-mean temperature change and three sets of spatial patterns of change derived from GCM results. In addition, the effect of either the presence or absence of a CO2 fertilization effect on vegetation is examined by using two levels of atmospheric CO2 concentration as a proxy variable. Results from three GCM experiments were used to produce different regional patterns of climate change. The three regional patterns for the conterminous United States range from: an increase in temperature above the global-mean level along with a significant decline in precipitation; temperature increases in line with the global-mean with an average increase in precipitation; and, with a sulfate aerosol effect added to in the same model, temperature increases that are lower than the global-mean. The resulting set of scenarios span a wide range of potential climate changes and allows examination of the relative importance of global-mean temperature change, regional climate patterns, aerosol cooling, and CO2 fertilization effects. [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]

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]

Globally, changing fire regimes due to climate is one of the greatest threats to ecosystems and society. In this paper, we present projections of future fire probability for the southcentral USA using downscaled climate projections and the Physical Chemistry Fire Frequency Model (PC2FM). Future fire probability is projected to both increase and decrease across the study region of Oklahoma, New Mexico, and Texas. Among all end-of-century projections, change in fire probabilities (CFPs) range from - 51 to + 240%. Greatest absolute increases in fire probability are shown for areas within the range of approximately 75 to 160 cm mean annual precipitation (MAP), regardless of climate model. Although fire is likely to become more frequent across the southcentral USA, spatial patterns may remain similar unless significant increases in precipitation occur, whereby more extensive areas with increased fire probability are predicted. Perhaps one of the most important results is illumination of climate changes where fire probability response (+, -) may deviate (i.e., tipping points). Fire regimes of southcentral US ecosystems occur in a geographic transition zone from reactant- to reaction-limited conditions, potentially making them uniquely responsive to different scenarios of temperature and precipitation changes. Identification and description of these conditions may help anticipate fire regime changes that will affect human health, agriculture, species conservation, and nutrient and water cycling. [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]

Banking and borrowing emission allowances provide temporal flexibility in cap-and-trade systems, which can enhance the economic efficiency of environmental policy while adhering to the same cumulative emission budget. This paper investigates the role of temporal ('when') flexibility from emission banking provisions under an economy-wide cap-and-trade policy in the USA. The current literature on meeting deep decarbonization targets almost exclusively assumes unlimited banking, which may bias policy recommendations and have important consequences for R&D prioritization and model development. Numerical experiments using the energy-economic model US Regional Energy, GHG, and Economy (US-REGEN) indicate that assumptions about banking materially impact cost and emission pathways in meeting long-term targets like 80% reductions by 2050 relative to 2005 levels. Given the stringency of long-run targets and convexity of marginal abatement costs, the cost-minimizing time path for mitigation with banking suggests that 2025 abatement should exceed the pledged level under the Paris Agreement (42% instead of 26-28%) to reduce future costs. Total policy costs are approximately 30% higher when banking is excluded; however, political economy barriers and uncertainty may limit the use of banking provisions despite their appeal on economic efficiency grounds. Banking on policy implementation with unlimited temporal flexibility may distort insights about the pace, extent, and economic impacts of future energy transitions associated with long-term abatement targets, especially for more stringent climate policies. [ABSTRACT FROM AUTHOR]

The impact of substituting biofuels for fossil fuels on carbon dioxide (CO) emissions has been debated for many years. A reason for the lack of resolution is that the method widely used to address the question, lifecycle analysis (LCA), is subjective. Its results irreducibly depend on untestable assumptions, notably those pertaining to system boundaries but also those for representing market effects. The best one can do is empirically constrain estimates of net CO impact using data that characterize important aspects of the overall system. Our 2016 paper, 'Carbon balance effects of U.S. biofuel production and use,' took such an approach, using field data to estimate the direct CO exchanges for a circumscribed vehicle-fuel system over the 2005-2013 period of expanding US biofuel use. De Kleine and colleagues criticize our work because it does not follow LCA conventions, arguing in particular for the primacy of the assumption that biofuels are inherently carbon neutral. This response refutes their critique; it reminds readers why the lifecycle paradigm fails for a dynamic system involving the terrestrial carbon cycle, stresses the need to bound an analysis of key carbon exchanges, and explains why the circular logic of LCA can be so beguiling. [ABSTRACT FROM AUTHOR]

This article focuses on the implications for the US National Climate Assessment (NCA) of diversifying information needs to support climate change risk management. It describes how the Third US National Climate Assessment (NCA3) evolved to begin to narrow the gap between information from climate and impact scientists and 'intermediaries' (individuals who have expertise in climate science, communication, and decision-support processes)-who are sometimes collectively described as 'producers' in this article-and the decision-making needs of a wide range of 'users' (individuals involved in advising or making a wide range of policy and management decisions). One step in the evolution of the NCA3 included adding a chapter to assess decision-support tools and systems being used in climate-related decisions. Another involved efforts to improve characterization of the level of confidence of NCA3 authors in their findings to help decision-makers and their advisors differentiate well-established and more preliminary conclusions. This paper lays out an argument for increasing the role of the NCA in assessing decision-support systems in the Fourth Assessment (NCA4) and the Sustained Assessment. It also briefly reviews approaches and potential next steps related to characterizing uncertainty and communicating confidence intended to improve application of assessment findings by decision-makers. [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]

Coastal areas are on the front lines of the impacts of climate change. The immediate impacts of temperature, precipitation and sea-level change affect rich but already threatened ecological systems and the most populated, highly developed, and economically vibrant regions of human activity on the planet. The specific vulnerabilities, impacts and adaptation options and activities vary greatly across the coastal areas of the US. The charge given to the coastal chapter team of the third US National Climate Assessment (NCA3, released in May 2014) was to discern the key vulnerabilities and most important cross-cutting concerns across the extensive coastline of the US. This paper is a reflection on what the coastal chapter team accomplished and how it was done (including author selection, staff support, technical inputs, the chapter development process, within- and cross-chapter integration, the review process, the delivery and high-impact release, the timeline of key assessment steps, and evaluation of the chapter development process). It concludes with eight lessons that might inform the activities of future collaborative author teams writing transdisciplinary, integrated assessment reports. [ABSTRACT FROM AUTHOR]

Well-targeted scientific assessments can support a range of decision-making processes, and contribute meaningfully to a variety of climate response strategies. This paper focuses on opportunities for climate assessments to be used more effectively to enhance adaptive capacity, particularly drawing from experiences with the third US National Climate Assessment (NCA3). We discuss the evolution of thinking about adaptation as a process and the importance of societal values, as well as the role of assessments in this evolution. We provide a rationale for prioritizing future assessment activities, with an expectation of moving beyond the concept of climate adaptation as an explicit and separable activity from 'normal' planning and implementation in the future. Starting with the values and resources that need to be protected or developed by communities rather than starting with an analysis of changes in climate drivers can provide opportunities for reframing climate issues in ways that are likely to result in more positive outcomes. A critical part of successful risk management is monitoring and evaluating the systems of interest to decision-makers and the effectiveness of interventions following integration of climate considerations into ongoing strategic planning activities and implementation. Increasingly this will require consideration of path dependency and coincident events. We argue that climate adaptation is a transitional process that bridges the gap between historically time-tested ways of doing business and the kinds of decision processes that may be required in the future, and that scientific assessments will be increasingly central to these transitions in decision processes over time. [ABSTRACT FROM AUTHOR]

The Third US National Climate Assessment (NCA3) was produced by experts in response to the US Global Change Research Act of 1990. Based on lessons learned from previous domestic and international assessments, the NCA3 was designed to speak to a broad public and inform the concerns of policy- and decision-makers at different scales. The NCA3 was also intended to be the first step in an ongoing assessment process that would build the nation's capacity to respond to climate change. This concluding paper draws larger lessons from the insights gained throughout the assessment process that are of significance to future US and international assessment designers. We bring attention to process and products delivered, communication and engagement efforts, and how they contributed to the sustained assessment. Based on areas where expectations were exceeded or not fully met, we address four common tensions that all assessment designers must confront and manage: between (1) core assessment ingredients (knowledge base, institutional set-up, principled process, and the people involved), (2) national scope and subnational adaptive management information needs, (3) scope, complexity, and manageability, and (4) deliberate evaluation and ongoing learning approaches. Managing these tensions, amidst the social and political contexts in which assessments are conducted, is critical to ensure that assessments are feasible and productive, while its outcomes are perceived as credible, salient, and legitimate. [ABSTRACT FROM AUTHOR]

During the development of the Third U.S. National Climate Assessment, an indicators system was recommended as a foundational product to support a sustained assessment process (Buizer et al. ). The development of this system, which we call the National Climate Indicators System (NCIS), has been an important early product of a sustained assessment process. In this paper, we describe the scoping and development of recommendations and prototypes for the NCIS, with the expectation that the process and lessons learned will be useful to others developing suites of indicators. Key factors of initial success are detailed, as well as a robust vision and decision criteria for future development; we also provide suggestions for voluntary support of the broader scientific community, and for funding priorities, including a research team to coordinate and prototype the indicators, system, and process. Moving forward, sufficient coordination and scientific expertise to implement and maintain the NCIS, as well as creation of a structure for scientific input from the broader community, will be crucial to its success. [ABSTRACT FROM AUTHOR]

Public discourse on climate change often refers to possible bias among climate scientists as a rationale for limited climate policy action by the United States. Part of this discussion is the association of scientists with environmental interest groups and whether such affiliations facilitate the perception that climate scientists lack objectivity. While surveys suggest that some climate scientists disapprove of affiliations with interest groups, recent research indicates that climate scientists are quite likely to be involved with environmental organizations. This paper compares the affiliations of scientists and the general public to discern whether scientists are uniquely likely to affiliate with interest groups or they simply share characteristics common to the public who also affiliate with these organizations. Our findings suggest that climate scientists are no more likely to donate money, but are less likely to sign a petition or attend a demonstration, when controlling for other factors. These results strengthen our understanding of the affiliations between scientists and interest groups and hold implications for the accuracy of popular perceptions of climate scientists. [ABSTRACT FROM AUTHOR]

This paper develops and applies methods to quantify and monetize projected impacts on terrestrial ecosystem carbon storage and areas burned by wildfires in the contiguous United States under scenarios with and without global greenhouse gas mitigation. The MC1 dynamic global vegetation model is used to develop physical impact projections using three climate models that project a range of future conditions. We also investigate the sensitivity of future climates to different initial conditions of the climate model. Our analysis reveals that mitigation, where global radiative forcing is stabilized at 3.7 W/m in 2100, would consistently reduce areas burned from 2001 to 2100 by tens of millions of hectares. Monetized, these impacts are equivalent to potentially avoiding billions of dollars (discounted) in wildfire response costs. Impacts to terrestrial ecosystem carbon storage are less uniform, but changes are on the order of billions of tons over this time period. The equivalent social value of these changes in carbon storage ranges from hundreds of billions to trillions of dollars (discounted). The magnitude of these results highlights their importance when evaluating climate policy options. However, our results also show national outcomes are driven by a few regions and results are not uniform across regions, time periods, or models. Differences in the results based on the modeling approach and across initializing conditions also raise important questions about how variability in projected climates is accounted for, especially when considering impacts where extreme or threshold conditions are important. [ABSTRACT FROM AUTHOR]

Changes in temperature, precipitation, sea level, and coastal storms will likely increase the vulnerability of infrastructure across the United States. Using four models that analyze vulnerability, impacts, and adaptation, this paper estimates impacts to roads, bridges, coastal properties, and urban drainage infrastructure and investigates sensitivity to varying greenhouse gas emission scenarios, climate sensitivities, and global climate models. The results suggest that the impacts of climate change in this sector could be large, especially in the second half of the 21st century as sea-level rises, temperature increases, and precipitation patterns become more extreme and affect the sustainability of long-lived infrastructure. Further, when considering sea-level rise, scenarios which incorporate dynamic ice sheet melting yield impact model results in coastal areas that are roughly 70 to 80 % higher than results that do not incorporate dynamic ice sheet melting. The potential for substantial economic impacts across all infrastructure sectors modeled, however, can be reduced by cost-effective adaptation measures. Mitigation policies also show potential to reduce impacts in the infrastructure sector - a more aggressive mitigation policy reduces impacts by 25 to 35 %, and a somewhat less aggressive policy reduces impacts by 19 to 30 %. The existing suite of models suitable for estimating these damages nonetheless covers only a small portion of expected infrastructure sector effects from climate change, so much work remains to better understand impacts on electric and telecommunications networks, rail, and air transportation systems. In addition, the effects of climate-induced extreme events are likely to be important, but are incompletely understood and remain an emerging area for research. [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]

Climate change impacts on water resources in the United States are likely to be far-reaching and substantial because the water is integral to climate, and the water sector spans many parts of the economy. This paper estimates impacts and damages from five water resource-related models addressing runoff, drought risk, economics of water supply/demand, water stress, and flooding damages. The models differ in the water system assessed, spatial scale, and unit of assessment, but together provide a quantitative and descriptive richness in characterizing water sector effects that no single model can capture. The results, driven by a consistent set of greenhouse gas (GHG) emission and climate scenarios, examine uncertainty from emissions, climate sensitivity, and climate model selection. While calculating the net impact of climate change on the water sector as a whole may be impractical, broad conclusions can be drawn regarding patterns of change and benefits of GHG mitigation. Four key findings emerge: 1) GHG mitigation substantially reduces hydro-climatic impacts on the water sector; 2) GHG mitigation provides substantial national economic benefits in water resources related sectors; 3) the models show a strong signal of wetting for the Eastern US and a strong signal of drying in the Southwest; and 4) unmanaged hydrologic systems impacts show strong correlation with the change in magnitude and direction of precipitation and temperature from climate models, but managed water resource systems and regional economic systems show lower correlation with changes in climate variables due to non-linearities created by water infrastructure and the socio-economic changes in non-climate driven water demand. [ABSTRACT FROM AUTHOR]

The U.S. Cooperative Extension Service was created 100 years ago to serve as a boundary or interface organization between science generated at the nation′s land grant universities and rural communities. Production agriculture in the US is becoming increasingly complex and challenging in the face of a rapidly changing climate and the need to balance growing crop productivity with environmental protection. Simultaneously, extension budgets are diminishing and extension personnel are stretched thin with numerous, diverse stakeholders and decreasing budgets. Evidence from surveys of farmers suggests that they are more likely to go to private retailers and consultants for information than extension. This paper explores the role that extension can play in facilitating climate change adaptation in agriculture using data from a survey of agricultural advisors in Indiana, Iowa, Michigan and Nebraska and a survey of extension educators in the 12 state North Central Region. Evidence from these surveys shows that a majority of extension educators believe that climate change is happening and that they should help farmers prepare. It also shows that private agricultural advisors trust extension as a source of information about climate change. This suggests that extension needs to continue to foster its relationship with private information providers because working through them will be the best way to ultimately reach farmers with climate change information. However extension educators must be better informed and trained about climate change; university specialists and researchers can play a critical role in this training process. [ABSTRACT FROM AUTHOR]

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]

Ever-increasing global warming has created a societal imperative to reach and engage youth, whose futures are at risk. In this paper, we evaluate the climate science knowledge, beliefs, attitudes, behavior and communication impact of an entertainment-education high school assembly program in a random sample of 49 schools (from population of 779 that received the intervention) and a panel of 1,241 students. Pre- and post-assembly surveys composed of questions from the Global Warming's Six Americas segmentation and intervention-specific measures were administered in classrooms. We demonstrate that exposure to climate science in an engaging edutainment format changes youths' knowledge, beliefs, involvement, and behavior positively and moves them to audience segments that are more engaged in the issue. The net impact of scaled, multi-sensory, captivating programs for youth could be a population shift in science-informed engagement in the issue of climate change. In addition, such programs can inspire youth for deeper engagement in school programs, personal action, and political and consumer advocacy. [ABSTRACT FROM AUTHOR]

As sea level rises, coastal communities will face increased risks of flooding, storm surge, and inundation. In some areas, structural protective measures will be built, and for some properties, accommodation to sea level rise may be possible. For other areas, however, some form of retreat will be either preferred on economic or sociopolitical grounds or required given fiscal constraints. This paper considers how society can proactively manage shoreline retreat in those locations where it is deemed the preferable policy. A three-part strategy is proposed: (1) reduce new development in the highest-risk areas; (2) adopt policies that allow for expected and orderly removal or modification of development as inundation occurs; and (3) take advantage of disasters to implement managed retreat approaches. Specific policies are recommended and the challenges of institutional change discussed. [ABSTRACT FROM AUTHOR]

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]

American Indian and Alaska Native tribes are uniquely affected by climate change. Indigenous peoples have depended on a wide variety of native fungi, plant and animal species for food, medicine, ceremonies, community and economic health for countless generations. Climate change stands to impact the species and ecosystems that constitute tribal traditional foods that are vital to tribal culture, economy and traditional ways of life. This paper examines the impacts of climate change on tribal traditional foods by providing cultural context for the importance of traditional foods to tribal culture, recognizing that tribal access to traditional food resources is strongly influenced by the legal and regulatory relationship with the federal government, and examining the multi-faceted relationship that tribes have with places, ecological processes and species. Tribal participation in local, regional and national climate change adaption strategies, with a focus on food-based resources, can inform and strengthen the ability of both tribes and other governmental resource managers to address and adapt to climate change impacts. [ABSTRACT FROM AUTHOR]

The likely intensification of extreme droughts from climate change in many regions across the United States has increased interest amongst researchers and water managers to understand not only the magnitude of drought impacts and their consequences on water resources, but also what they can do to prevent, respond to, and adapt to these impacts. Building and mobilizing 'adaptive capacity' can help in this pursuit. Researchers anticipate that drought preparedness measures will increase adaptive capacity, but there has been minimal testing of this and other assumptions about the governance and institutional determinants of adaptive capacity. This paper draws from recent extreme droughts in Arizona and Georgia to empirically assess adaptive capacity across spatial and temporal scales. It combines quantitative and qualitative methodologies to identify a handful of heuristics for increasing adaptive capacity of water management to extreme droughts and climate change, and also highlights potential tradeoffs in building and mobilizing adaptive capacity across space and time. [ABSTRACT FROM AUTHOR]

This paper conducts an empirical analysis of the factors affecting U.S. public concern about the threat of climate change between January 2002 and December 2010. Utilizing Stimson's method of constructing aggregate opinion measures, data from 74 separate surveys over a 9-year period are used to construct quarterly measures of public concern over global climate change. We examine five factors that should account for changes in levels of concern: 1) extreme weather events, 2) public access to accurate scientific information, 3) media coverage, 4) elite cues, and 5) movement/countermovement advocacy. A time-series analysis indicates that elite cues and structural economic factors have the largest effect on the level of public concern about climate change. While media coverage exerts an important influence, this coverage is itself largely a function of elite cues and economic factors. Weather extremes have no effect on aggregate public opinion. Promulgation of scientific information to the public on climate change has a minimal effect. The implication would seem to be that information-based science advocacy has had only a minor effect on public concern, while political mobilization by elites and advocacy groups is critical in influencing climate change concern. [ABSTRACT FROM AUTHOR]

Effectively communicating the complexity of climate change to the public is an important goal for the climate change research community, particularly for those of us who receive public funds. The challenge of communicating the science of climate change will be reduced if climate change researchers consider the links between personality types, communication tendencies and learning preferences. Jungian personality type is one of many factors related to an individual's preferred style of taking in and processing information, i.e., preferred communication style. In this paper, we demonstrate that the Jungian personality type profile of interdisciplinary, early career climate researchers is significantly different from that of the general population in the United States. In particular, Ph.D. climate researchers tend towards Intuition and focus on theories and the 'big picture', while the U.S. general population tends towards Sensing and focuses on concrete examples and experience. There are other differences as well in the way the general public as a group prefers to take in information, make decisions, and deal with the outer world, compared with the average interdisciplinary climate scientist. These differences have important implications for communication between these two groups. We suggest that climate researchers will be more effective in conveying their messages if they are aware of their own personality type and potential differences in preferred learning and communication styles between themselves and the general public (and other specific audiences), and use this knowledge to more effectively target their audience. [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 uses a modified form of Thornthwaite’s moisture index to better quantify climate variability by integrating the effects of temperature and precipitation. Using the moisture index, trends were evaluated over the last 112 years (1895–2006), when unique changes in temperature and precipitation have been documented to have occurred. In addition, data on potential evapotranspiration and the moisture index were used to investigate changing climate and vegetation regions. The results show that the eastern half of the country has been getting wetter, even as temperatures have continued to increase in many areas. In particular, conditions have become wetter in the South, Northeast, and East North Central regions. The changing climate is illustrated by computing climate and vegetation regions for three 30-year periods (1910–1939, 1940–1969, and 1970–1999). Climate regions based on the moisture index show an expansion of the Humid region (where precipitation vastly exceeds climatic demands for water) across the East as well as a westward shift in the zero moisture index line. In terms of vegetation zones, the most dramatic change occurs across the Midwestern prairie peninsula where the wetter conditions lead to a westward expansion of conditions favorable for oak–hickory–pine vegetation. [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]

Greenhouse gas abatement policies will increase the demand for renewable sources of energy, including bioenergy. In combination with a global growing demand for food, this could lead to a food-fuel competition for bio-productive land. Proponents of bioenergy have suggested that energy crop plantations may be established on less productive land as a way of avoiding this potential food-fuel competition. However, many of these suggestions have been made without any underlying economic analysis. In this paper, we develop a long-term economic optimization model (LUCEA) of the U.S. agricultural and energy system to analyze this possible competition for land and to examine the link between carbon prices, the energy system dynamics and the effect of the land competition on food prices. Our results indicate that bioenergy plantations will be competitive on cropland already at carbon taxes about US $20/ton C. As the carbon tax increases, food prices more than double compared to the reference scenario in which there is no climate policy. Further, bioenergy plantations appropriate significant areas of both cropland and grazing land. In model runs where we have limited the amount of grazing land that can be used for bioenergy to what many analysts consider the upper limit, most of the bioenergy plantations are established on cropland. Under the assumption that more grazing land can be used, large areas of bioenergy plantations are established on grazing land, despite the fact that yields are assumed to be much lower (less than half) than on crop land. It should be noted that this allocation on grazing land takes place as a result of a competition between food and bioenergy production and not because of lack of it. The estimated increase in food prices is largely unaffected by how much grazing land can be used for bioenergy production. [ABSTRACT FROM AUTHOR]

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]

This paper tests whether climate has an impact on per capita rural income. The study finds that total (agricultural and nonagricultural) income in rural counties and municipios in the US and Brazil are affected by climate. The study demonstrates that this income effect is due to changes in the net value of agriculture. Regions with better climates for agriculture support higher rural incomes and regions with poor climates have more rural poverty. The results also suggest that global warming will likely increase rural poverty. [ABSTRACT FROM AUTHOR]

One of the banes of farming is the frequent complete loss of crops due to adverse weather conditions or pests. In this paper, we explore what causes catastrophic crop failures. The study demonstrates that 39% of the variation in expected crop failure rates across the United States can be explained by soils and climate. The analysis shows that precipitation, soils, and especially temperature all explain average crop failure rates. Surprisingly, the analysis did not suggest that annual warming would increase crop failure rates. However, decreases in annual precipitation or increases in interannual or diurnal variation would all be harmful to crops. [ABSTRACT FROM AUTHOR]

The purpose of this paper is to develop and apply a new method to assess economic potential for agricultural greenhouse gas mitigation. This method uses secondary economic data and conventional econometric production models, combined with estimates of soil carbon stocks derived from biophysical simulation models such as Century, to construct economic simulation models that estimate economic potential for carbon sequestration. Using this method, simulations for the central United States show that reduction in fallow and conservation tillage adoption in the wheat-pasture system could generate up to about 1.7 million MgC/yr, whereas increased adoption of conservation tillage in the corn--soy--feed system could generate up to about 6.2 million MgC/yr at a price of $200/MgC. About half of this potential could be achieved at relatively low carbon prices (in the range of $50 per ton). The model used in this analysis produced estimates of economic potential for soil carbon sequestration potential similar to results produced by much more data-intensive, field-scale models, suggesting that this simpler, aggregate modeling approach can produce credible estimates of soil carbon sequestration potential. Carbon rates were found to vary substantially over the region. Using average carbon rates for the region, the model produced carbon sequestration estimates within about 10% of those based on county-specific carbon rates, suggesting that effects of spatial heterogeneity in carbon rates may average out over a large region such as the central United States. However, the average carbon rates produced large prediction errors for individual counties, showing that estimates of carbon rates do need to be matched to the spatial scale of analysis. Transaction costs were found to have a potentially important impact on soil carbon supply at low carbon prices, particularly when carbon rates are low, but this effect diminishes as carbon prices increase. [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]

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 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]