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Widespread adoption of regenerative agriculture practices is an integral part of the US plan to achieve net-zero greenhouse gas emissions by 2050. National incentives have particularly increased for the adoption of cover crops (CCs), which have presumably large carbon (C) sequestration potential. However, assessments of national CC climate benefits have not fully considered regional variability, changing C sequestration rates over time, and potential N 2 O trade-offs. Using the DayCent soil biogeochemical model and current national survey data, we estimate CC climate change mitigation potential to be 39.0 ± 24.1 Mt CO 2 e year -1 , which is 45%-65% lower than previous estimates, with large uncertainty attributed to N 2 O impacts. Three-fourths of this climate change mitigation potential is concentrated in the North Central, Southern Great Plains and Lower Mississippi regions. Public investment should be focused in these regions to maximize CC climate benefits, but the national contribution of CC to emissions targets may be lower than previously anticipated., (© 2024 John Wiley & Sons Ltd.)

Flash droughts, characterized by rapid onset and development, present significant challenges to agriculture and climate mitigation strategies. Operational drought monitoring systems, based on precipitation, soil moisture deficits, or temperature anomalies, often fall short in timely detection of these events, underscoring the need for customized identification and monitoring indices that account for the rapidity of flash drought onset. Recognizing this need, this paper introduces a global flash drought inventory from 1990 to 2021 derived using the Soil Moisture Volatility Index (SMVI). Our work expands the application of the SMVI methodology, previously focused on the United States, to a global scale, providing a tool for understanding and predicting these rapidly developing phenomena. The dataset encompasses detailed event characteristics, including onset, duration, and severity, across diverse climate zones. By integrating atmospheric variables through their impact on soil moisture, the inventory offers a platform for analyzing the drivers and impacts of flash droughts, and serves as a large, consistent dataset for use in training and evaluating flash drought prediction models. [ABSTRACT FROM AUTHOR]

As climate change impacts increase, communicators must engage as many audiences as possible in climate action. One potentially underrated audience is video gamers. Two-thirds of Americans play video games, and video games are a potentially effective climate change communication tool. However, little research has examined whether video gamers have unique value as a target audience for climate communication, and if they do, what might be effective ways to reach them. To address this need, we use two surveys including self-identified video game players in the United States to measure their current engagement with climate change, including through video gaming. In Study 1, a nationally representative survey in the United States (N = 1,006), we found that being a video gamer was slightly positively associated with intentions to take collective action on global warming. In Study 2, restricted to gamers in the United States (N = 2,034), we found that having more friends and family who played video games, and/or being exposed to global warming content in gaming, were also positively associated with collective action intentions. These findings were consistent even after controlling for potential confounding variables such as age, political party, and global warming attitudes. Results suggest that video gamers are a worthwhile potential audience for future climate change communication, combatting the stereotype of video gamers as disengaged or antisocial, at least in the context of climate change. Our study also identifies several potential avenues for future communication with video gamers, particularly outreach to and engagement with gaming communities. [ABSTRACT FROM AUTHOR]

Existing estimates of the climate mitigation potential from cropland carbon sequestration (C‐sequestration) are limited because they tend to assume constant rates of soil organic carbon change over all available cropland area, use relatively coarse land delineations, and often fail to adequately consider the agronomic and socioeconomic dimensions of agricultural land use. This results in an inflated estimate of the C‐sequestration potential. We address this gap by defining a more appropriate land base for cover cropping in the United States for C‐sequestration purposes: stable croplands in annual production systems that can integrate cover cropping without irrigation. Our baseline estimate of this suitable stable cropland area is 32% of current U.S. cropland extent. Even an alternative, less restrictive definition of stability results in a large reduction in area (44% of current U.S. croplands). Focusing cover crop implementation to this constrained land base would increase durability of associated C‐sequestration and limit soil carbon loss from land conversion to qualify for carbon‐specific incentives. Applying spatially‐variable C‐sequestration rates from the literature to our baseline area yields a technical potential of 19.4 Tg CO2e yr−1 annually, about one‐fifth of previous estimates. We also find the cost of realizing about half (10 Tg CO2e yr−1) of this potential could exceed 100 USD Mg CO2e−1, an order of magnitude higher than previously thought. While our economic analyses suggest that financial incentives are necessary for large‐scale adoption of cover cropping in the U.S., they also imply any C‐sequestration realized under such incentives is likely to be additional. Plain Language Summary: As a "Nature‐based Climate Solution" (NCS), the practice of cover cropping has received widespread attention and investment recently. Through cover cropping, croplands may be able to absorb and hold more carbon in soil, drawing down CO2 in the atmosphere (i.e., sequester carbon). However, the sequestration that is feasible, which reflects socioeconomic and land use considerations, remains unquantified. We estimate this feasible potential for carbon sequestration in the U.S. croplands from cover cropping and find it to be a fraction of previous estimates. A large portion of the reduction is due to our use of a more realistic and rigorous definition of the land area suitable for cover cropping for climate mitigation purposes. This land area comprises "croplands remaining croplands" (or stable croplands) that are planted to annual crops, like corn and soybeans, because they can more easily integrate the practice. We exclude irrigated croplands to conserve water resources. At just under 44 million ha, our baseline area estimate is 32% of the current U.S. cropland extent. The rest of the reduction is associated with our use of more conservative rates of increase in soil carbon from cover cropping than earlier studies that are more realistic for assessing soil carbon sequestration potential over large areas. Our economic analyses suggests that without financial incentives, implementing cover cropping could be expensive for most U.S. farmers. This high cost hurdle needs to be evaluated against the cost‐effectiveness of alternatives that compete for the same limited resources for climate mitigation. Key Points: For U.S. croplands, the feasible potential of carbon sequestration from cover cropping is a fraction of previous estimatesDefining the land base suitable for mitigation practices more realistically and rigorously is critical to estimating the feasible potentialCover cropping, though beneficial for soil health, may not be a low‐cost pathway for climate mitigation at scale in the U.S. [ABSTRACT FROM AUTHOR]

In light of the International Panel on Climate Change's findings, this article underscores the detrimental effects of climate misinformation in the United States and its role in impeding public understanding and action. Leveraging the power of education, an eighth-grade 5E instructional unit is introduced to foster students' climate literacy by delving into the human-induced causes of climate change. Through the 5E instructional model, students are presented with diverse materials, activities, and projects. These include discussions on climate change activism, interactive simulations, and experiments mirroring Eunice Foote's groundbreaking work, culminating in a student-produced video project highlighting climate change causes. By melding social perspectives and rigorous scientific exploration, this NGSS-aligned unit draws from relevant climate literacy research and aims to produce a generation of students equipped to actively and knowledgeably participate in global climate discourse. [ABSTRACT FROM AUTHOR]

We shed new light on a long-standing question in political science: When confronted with costly policy choices, do citizens form their preferences using material (economic) concerns or other-regarding motivations, such as the distribution of costs, and how are these moderated by political ideology? Using the case of carbon taxation, a widely advocated policy solution to climate change, we conducted survey experiments in Germany and the United States to assess the relative importance of these forms of preferences. The results show that individuals are primarily concerned with how a carbon tax would affect their individual income. There are also important cross-national differences with high-income German respondents being more receptive to redistributive policy design, especially in contrast to high-income Democrats who significantly decrease support for carbon taxation. These findings highlight how the constituencies generated by new policies can significantly alter the distribution of mass support for action on emerging societal problems. [ABSTRACT FROM AUTHOR]

Wildfires are becoming more frequent due to the global climate change. Large amounts of greenhouse gases emitted by wildfires can lead to increases in extreme climate events. Accurately estimating the greenhouse gas carbon dioxide (CO2) emissions from wildfires is important for mitigation of climate change. In this paper, we develop a novel method to estimate wildfire CO2 emissions from the relationship between local CO2 emissions and XCO2 anomalies. Our method uses the WRF-Chem assimilation system from OCO-2 XCO2 retrievals which coupled with Data Assimilation Research Testbed (DART). To validate our results, we conducted three experiments evaluating the wildfire CO2 emissions over the conterminous United States. The four-month average wildfire emissions from July to October in 2015∼2018 were estimated at 4.408 Tg C, 1.784 Tg C, 1.514 Tg C and 2.873 Tg C, respectively. Compared to the average of established inventories CT2019B, FINNv1.5 and GFASv1.2 fire emissions, our estimates fall within one standard deviation, except for 2017 due to lacking of OCO-2 XCO2 retrievals. These results suggest that the regional carbon assimilation system, such as WRF-Chem/DART, using OCO-2 XCO2 retrievals has a great potential for accurately tracking regional wildfire emissions. [ABSTRACT FROM AUTHOR]

There is growing urgency for improved public and commercial services to support a resilient, secure, and thriving United States (US) in the face of mounting decision‐support needs for environmental stewardship and hazard response, as well as for climate change adaptation and mitigation. Sustained space‐based Earth observations are critical infrastructure to support the delivery of science and decision‐support information with local, national, and global utility. This is reflected in part through the United States' sustained support of a suite of weather and land‐imaging satellites. However, outside of these two areas, the US lacks an overarching, systematic plan or framework to identify, prioritize, fund, and implement sustained space‐based Earth observations to meet the Nation's full range of needs for science, government policy, and societal support. To aid and accelerate the discussion on our nation's needs, challenges and opportunities associated with sustained critical space‐based Earth observations, the Keck Institute for Space Studies (KISS) sponsored a multi‐week think‐tank study to offer ways forward. Based on this study, the KISS study team suggests the establishment of a robust coordination framework to help address US needs for sustained Earth observations. This coordination framework could account for: (a) approaches to identify and prioritize satellite observations needed to meet US needs for science and services, (b) the rapidly evolving landscape of space‐based Earth viewing architecture options and technology improvements with increasing opportunities and lower cost access to space, and (c) the technical and programmatic underpinnings required for proper and comprehensive data stewardship to support a wide range of research and public services. Plain Language Summary: The Keck Institute of Space Studies has carried out a think tank study to codify best practices, articulate successes, and identify challenges and opportunities in the prioritization, acquisition, curation, and stewardship of sustained space‐based Earth observations. The goal of the study is to accelerate discussion and plans for a greater and more impactful US contribution to the global satellite observing system that will support decision‐making regarding climate change, environmental hazards, and national security. Based on this study, the KISS study team suggests the establishment of a nimble and responsive coordination framework to help guide and shepherd US concerns regarding sustained Earth observations. This coordination framework should account for: (a) approaches to identify and prioritize satellite observations needed to meet US needs for science and services, (b) the rapidly evolving landscape of space‐based Earth viewing architecture options and technology improvements with increasing opportunities and lower cost access to space and (c) the technical and programmatic underpinnings required for proper and comprehensive data stewardship with a broad science and services user base in mind. Key Points: There is growing urgency for improved public and commercial services to support a resilient, secure, and thriving USSpace‐based Earth observations represent an essential component of the infrastructure needed to support the delivery of needed informationThe US would benefit from an overarching plan for sustained Earth observations to support our science, policy, and resilience goals [ABSTRACT FROM AUTHOR]

The governance challenges embedded in climate change are daunting. Conventional logic holds that national and international action is necessary. While the United States is a major source of Greenhouse Gas (GHG) emissions – second only to China – national action on climate change has been lacking. However, hundreds of subnational US governments and thousands of industrial facilities are actively engaged in addressing climate change. Given the potential mismatch between the global nature of the problem and the policy reach of subnational governments, we evaluate the extent to which polycentric variation in subnational climate action is associated with changes in GHG emissions. We develop a unique data set that incudes facility‐level GHG emissions from major industrial sectors in the United States over 8 years and subnational climate governance action across all 50 states. This large‐N data set allows us to systematically test hypothesis from polycentric governance. This type of comparative analysis can help to better understand the conditions under which polycentric governance is associated with improved climate change outcomes, that is, declining GHG emissions. Our results suggest that even when controlling for past emissions, some elements of polycentric governance are associated with decreases in GHG emissions. Future research would benefit from augmenting the large N comparative analysis presented here with mixed methods research to more fully understand the dynamic processes shaping both climate policy and GHG emissions. [ABSTRACT FROM AUTHOR]

The passage of the Inflation Reduction Act (IRA) in August 2022 was an important step forward in American climate policy. The Act is essential to the United States' goal of effective climate change mitigation efforts, and other countries have even begun to use it as a model for climate mitigation. The Inflation Reduction Act (IRA) provides the framework by which the United States will transition away from fossil fuels and move towards an energy grid powered predominantly by renewable sources. For the first time, the Act addresses head-on the climate and environmental injustices that exist in the United States due to decades of structural inequities that have directly harmed people of color and low-income individuals. However, these environmental injustices are connected to housing injustice, which also disproportionately harms these same vulnerable groups. Low-income tenants often bear the brunt of all of these injustices, due to a lack of legal protection, stability, and resiliency in their homes. While there are crucial environmental justice provisions in the Inflation Reduction Act, its preeminent method to shift to renewable energy is the use of tax credits, which favor energy developers and leave tenants behind. Tax credits are likely to reinforce existing inequalities, and here, incentivize development that could lead to further gentrification. Without housing justice, there is no environmental justice nor climate justice. This Note proposes that in conjunction with the IRA, there needs to be a legislative push for localized, renter-protective policies that will create stability for low-income renters and allow the benefits of the IRA (like clean energy, greener neighborhoods, and cheaper energy prices), to be shared with the communities that need these benefits the most. [ABSTRACT FROM AUTHOR]

This study examined urban park visitors' concerns, beliefs, decision to visit, and support for management actions regarding climate change. A questionnaire was administered to 429 visitors at three city-owned parks in a Midwestern community in the United States, yielding a 46.4% response rate (n = 199). Overall, results showed participants were concerned about the impacts of climate change and were supportive of managerial actions aimed at mitigating its impacts. We found that tick and mosquito-borne diseases were most likely to impact visitation. Recycling bins received the highest support for mitigating the impacts of climate change. Additionally, we observed differences across various demographics, such as non-white visitors being more vulnerable to the impacts of climate change while making trip decisions, and low-income visitors being more likely to choose incorrect climate change causations. We suggest that urban visitors can offer some important managerial insights for addressing climate change impacts. [ABSTRACT FROM AUTHOR]

Climate change mitigation depends on actions that affect the public interest and lead to widespread changes in public attitudes and behavior. With the global outbreak of the COVID-19 pandemic, humanity faced a more imminent threat to its well-being and viability. This retrospective cross-sectional study examines how public interest in climate change was attenuated by the severity of the COVID-19 pandemic using Google Trends Search Volume Index (SVI), weather, and climate data on a United States state-level basis during the first two years of the pandemic from 2020 to 2022. To identify channels through which the COVID-19 pandemic affected information demand on climate change, a novel fixed effect regression model of public climate change interest was developed. The measure captures changes in the climate change SVI independent of weather and climate conditions, comprising pandemic-related changes in living circumstances such as COVID-19-related cases and deaths, mask mandates, and the proportion of the vaccinated population. Our results indicate that public interest in climate change was systematically attenuated by the severity of the COVID-19 pandemic. In addition, this study provides an approach for identifying drivers of public interest in climate change. [ABSTRACT FROM AUTHOR]

Continued climate warming, together with the overall evaluation and implementation of a range of climate mitigation and adaptation approaches, has prompted increasing research into proposed solar climate intervention methods, such as stratospheric aerosol injection (SAI). SAI would use aerosols to reflect a small amount of incoming solar radiation away from Earth to stabilize or reduce future warming due to increasing greenhouse gas concentrations. Research into the possible risks and benefits of SAI relative to the risks from climate change is emerging. There is not yet, however, an adequate understanding of how SAI might impact human and natural systems. For instance, little to no research to date has examined how SAI might impact environmental conditions critical to the formation of severe convective weather over the United States (US). This study uses ensembles of Earth system model simulations of future climate change, with and without hypothetical SAI deployment, to examine possible future changes in thermodynamic and kinematic parameters critical to the formation of severe weather during convectively active seasons over the US Results show that simulated forced changes in thermodynamic parameters are significantly reduced under SAI relative to a climate change (SSP2‐4.5) world, while simulated changes in kinematic parameters are more difficult to distinguish. Also, unforced internal climate variability is likely to significantly modulate the projected forced climate changes over large regions of the US. Plain Language Summary: Human‐caused climate warming is projected to increase occurrences of environmental conditions which favor the formation of severe weather, such as thunderstorms. Stratospheric aerosol injection (SAI) is a form of climate intervention which aims to cool the planet by injecting sunlight‐reflecting particles into the stratosphere, a part of the upper atmosphere. This study investigates how SAI might impact future projections of the environmental conditions which favor the formation of severe weather. One set of climate models simulations show that future increases of the occurrence of temperature driven environmental characteristics that favor the formation of severe weather could be avoided if SAI were to be implemented. These simulations also show that future projections of environmental characteristics that favor the formation of severe weather that are dynamically driven may not be significantly impacted by the implementation of SAI. Climate variability that is not human‐driven may also significantly impact future projections of the environmental conditions which favor severe weather formation, whether or not SAI has been implemented. Key Points: Thermodynamic parameters relevant to severe weather formation are projected to increase in magnitude over the US due to climate changeStratospheric aerosol injection may prevent many of these projected increasesInternal decadal‐scale climate variability is likely to impact future projections of regional changes in convective weather environments [ABSTRACT FROM AUTHOR]

Climate change is a wicked problem, defying simple resolution. Education in various forms and at various levels has sought to improve understanding and stimulate climate change action in young people. There exists, however, a certain wickedness in education systems as well that makes climate change education difficult to enact successfully. These include an unsupportive education environment where academic standards related to climate change are missing, the lack of an inquiry-based pedagogy that can be well-suited to investigating topics like climate change with no easy answers, and ill-prepared teachers who do not fully know both the physical science and social aspects of the topic. A review of education standards in the United States and the literature on the latter two issues is used to make the argument that it is the geography classroom that can serve as the best unifying space that is most supportive of holistic and meaningful climate change education. This future is possible should we be successful in amending standards, pedagogy, and teacher preparation. [ABSTRACT FROM AUTHOR]

While the majority of adults across the United States report that they believe that global warming is happening, far fewer report discussing global warming (Howe et al., 2015, https://doi.org/10.1038/nclimate2583; Marlon et al., 2022, https://climatecommunication.yale.edu/visualizations‐data/ycom‐us/). One way to inspire further climate action and engagement is to increase individuals' capacity to confidently and effectively discuss climate change. Climate communication science highlights that such communication is most effective when it is anecdotal, narrative, tailored to the audience, and place‐based. To generate climate conversations and inspire action in a variety of communities, partners at the University of Minnesota Extension piloted a program to train community members from across the state of Minnesota in effective climate communication through a series of instructional workshops, coaching, and participant‐led communication activities. Following the training portion of the program, participants identified and hosted their own climate‐related communication activities in their communities. These "climate conversations" took place across Minnesota and included community events, dialogue with elected leaders, and conversations stimulated through literature, among other activities. In their communities, program participants sparked conversations, initiated long‐term climate action efforts, and improved their sense of efficacy in response to climate change. Participants also reported that they improved their climate conversation skills, increased their local climate knowledge, established a support network with fellow participants, had reduced anxiety around communicating, and increased their confidence in being able to communicate about climate change in their communities. This pilot program provides a framework for future cohort‐ and community‐based climate communication programs in the state and beyond. Plain Language Summary: More frequent, effective climate conversations initiated by a diversity of trusted voices can help to increase climate concern and desire for action at the community level. However, in the United States, there is a disconnect between the level of concern individuals have about climate change and the extent to which individuals talk about the issue. To help bridge this gap, the University of Minnesota Climate Adaptation Partnership developed a training program aimed at inspiring and equipping local community members across Greater Minnesota with the skills and confidence to have effective conversations about climate change in their communities. This paper summarizes the programmatic activities we used to support our goals, and some reflections on the program's results. This pilot program provides a framework for future efforts that can be facilitated by Extension programs, community‐based organizations, universities, and others to inspire and accelerate similar community‐centered climate conversations. Key Points: We piloted a training program to teach Minnesotans to effectively communicate about climate change and its impacts on their communitiesParticipants improved behavioral and conversation skills to communicate about climate change more effectivelyThis program provides a framework for future programs aimed at increasing the diversity of people engaging in local climate conversations [ABSTRACT FROM AUTHOR]

Cities face substantial risks of economic and physical losses from repeated exposure to climate hazards exacerbated by climate change. Drawing from the climate action and policy mix literatures, this study conceptualizes "climate action mix" defined as the diverse policy actions adopted by city governments to adapt to and mitigate the effects of climate hazards. This study makes a key contribution by analyzing the relation between the variety of hazards and the diversity of cities' climate action mixes. Deploying a modified Shannon diversity index, we develop a new measure of climate action mix by considering the breadth across different actions, and the depth of these efforts as measured by the progress along the policy cycle. We study an expansive range of mitigation and adaptation actions without imposing any domain or jurisdictional limitations in 162 cities across the United States. The analysis reveals a bifurcation in approaches where some cities have not adopted any policies, while others have a diverse mix of adaptation and mitigation actions in various stages of policy progression. We find that climate hazards drive local action—cities that experience multiple threats react by taking a diverse mix of climate actions. Cities broadly utilize global climate networks that offer policy learning opportunities and local networks that might promote a shared understanding of environmental threats leading to diverse climate action mixes. Finally, a city's capacity to develop climate adaptation and mitigation plans is positively related to a diverse portfolio of climate actions. [ABSTRACT FROM AUTHOR]

Local governments have led the way on climate action in the United States. While the federal government has largely stood to the side, local governments have made great efforts to adopt policies aimed at reducing greenhouse gas emissions. A large and robust literature in urban politics has explored the variables that influence local government action on climate change in the United States. Issue severity and resident ideological preferences have been identified as two of the most important factors in local climate action. Governments that are more likely to face major impacts from climate, such as coastal communities, and governments serving more liberal residents have both been found to pursue climate policy at higher rates. In this paper we suggest that these relationships are better understood as conditional. We argue that the effect of issue severity will be moderated by ideology. When residents are liberal, issue severity will matter. When residents are conservative, the impact will be muted. We find strong evidence for this hypothesis. Coastal governments and governments that have experienced drought adopt more climate policies, but this is conditional on the ideology of residents. [ABSTRACT FROM AUTHOR]

In the United States, state governments have been the locus of action for addressing climate change. However, the lack of a holistic measure of state climate policy has prevented a comprehensive assessment of state policies' effectiveness. Here, we assemble information from 25 individual policies to develop an aggregate index of state climate policies from 2000-2020. The climate policy index highlights variation between states which is difficult to assess in single policy studies. Next, we examine the environmental and economic consequences of state climate policy. A standard-deviation increase in climate policy is associated with a 5% reduction in per-capita electricity-sector CO2 emissions and a 2% reduction in economy-wide CO2 emissions per capita. We do not find evidence that more stringent climate policy harms states' economies. Our results make clear the benefits of state climate policy, while showing that current state efforts are unlikelyto meet the US goal under the Paris Climate Accord. In the US, states vary in their efforts to address climate change. Stronger state climate policies reduce CO2 emissions without harming the economy, but these reductions are unlikely to meet the goals in the Paris Climate Accord. [ABSTRACT FROM AUTHOR]

Wildfires and land use play a central role in the long‐term carbon (C) dynamics of forested ecosystems of the United States. Understanding their linkages with changes in biomass, resource use, and consumption in the context of climate change mitigation is crucial. We reconstruct a long‐term C balance of forests in the contiguous U.S. using historical reports, satellite data, and other sources at multiple scales (national scale 1926–2017, regional level 1941–2017) to disentangle the drivers of biomass C stock change. The balance includes removals of forest biomass by fire, by extraction of woody biomass, by forest grazing, and by biomass stock change, their sum representing the net ecosystem productivity (NEP). Nationally, the total forest NEP increased for most of the 20th century, while fire, harvest and grazing reduced total forest stocks on average by 14%, 51%, and 6%, respectively, resulting in a net increase in C stock density of nearly 40%. Recovery from past land‐use, plus reductions in wildfires and forest grazing coincide with consistent forest regrowth in the eastern U.S. but associated C stock increases were offset by increased wood harvest. C stock changes across the western U.S. fluctuated, with fire, harvest, and other disturbances (e.g., insects, droughts) reducing stocks on average by 14%, 81%, and 7%, respectively, resulting in a net growth in C stock density of 14%. Although wildfire activities increased in recent decades, harvest was the key driver in the forest C balance in all regions for most of the observed timeframe. Plain Language Summary: We estimate past forest fires in four regions of the contiguous United States from 1926 to 2017 using historical statistics and satellite data. We compare the biomass removed from forests by wildfires, wood harvest, and forest grazing to identify which of these indicators had the strongest impact on forest biomass. Fire suppression and biomass recovery from past harvest in the twentieth century led to biomass regrowth. Forest regrowth was stronger in the East of the United States than in the West. Recently, wildfires have increased in the West. Higher tree mortality, drought, windthrow, and insects counteracted forest growth in the West. We conclude that fire suppression contributed to forest regrowth in the past, but harvest had the strongest impact in all regions. We show that the connection between wildfires, harvest, and grazing is an important factor for biomass change in forests and needs to be investigated over long time periods. Key Points: We present a new data set, reconstructing biomass removals by fire, harvest, and grazing in U.S. forests on a regional scale from 1941 to 2017Harvest and fire were the most intensive removals of biomass over the 20th century. Regional trends diverge from national trendsIn the context of natural climate solutions, long‐term and regional dynamics of interconnected drivers of forest biomass change need to be considered [ABSTRACT FROM AUTHOR]

Despite the rise of climate justice movements worldwide, climate justice concerns are insufficiently addressed in recent U.S. policy, and public understanding is not yet widespread. To explore possible avenues for climate justice communication, this analysis examines U.S. climate activists' recommended target audiences and communication strategies. Drawing on 67 conversational interviews and 112 online surveys with activists, the analysis discusses strategies for engaging two high-priority audiences: (1) social justice advocates who do not see the climate crisis as a justice issue and (2) climate action advocates who do not view climate justice as integral to climate solutions. The analysis also identifies a low-priority audience category of climate justice deniers, or people who—independent of their views on the climate crisis itself—are apathetic to its social justice implications. These results propose a novel audience segmentation for climate justice communication and consolidate activists' recommendations for engaging each audience, thus providing a grounding for further experimental work. [ABSTRACT FROM AUTHOR]

This study's primary objective was to assess pharmacists' knowledge and beliefs regarding climate change and health. Secondary objectives included assessing perceptions of its relevance to pharmacists and pharmacy practice as well as potential roles in mitigating climate change. An 18-question, anonymous survey was developed using questions adapted from previously published surveys that evaluated the general public's views of international issues and health professionals' perceptions of climate change and health, with additions specific to the Midwestern United States and Ohio. It was sent electronically to a random sample of 500 registered pharmacists living and working in Ohio. Data were analyzed using descriptive and nonparametric statistics. Seventy pharmacists participated in the study. The majority of respondents (78.3%) believed climate change is happening. More respondents recognized climate change to be a great or moderate threat to human health worldwide (72.7%) than to patients in their community (45.4%; P <.001). A little more than half (54.5%) thought climate change was relevant to pharmacy practice. Perceived barriers that reduced willingness to communicate with the public about this topic included lack of time (73.4%) or knowledge (49.2%) and feeling that it would not make a difference (46.1%) or it is too controversial (35.4%). Respondents believed pharmacists could have the greatest impact through increasing sustainability in the health care system (48.5%). Most respondents recognized that climate change is happening, is a threat to human health worldwide, and is relevant to pharmacy. However, many did not recognize its potential impact on their own patients or their role in climate action, showing a need for more education on this topic. As these are the first data collected among pharmacists in the United States, additional studies should be performed in other parts of the country as opinions may vary based on personal experience with or exposure to impacts of climate change. [ABSTRACT FROM AUTHOR]

Communicating about actions to address climate change is critical to mobilize collective actions, and enact policies for climate change mitigation (prevention) and adaptation to climate change. The current study assessed factors associated with climate change action (CCA) communications in the US. Respondents were recruited through Prolific, an online survey research platform. The sample was restricted to the 599 respondents who reported that the issue of climate change was extremely or very important to them. Key outcome variables included (1) talking to family/friends about CCA, (2) texting/emailing family/friends about CCA, and (3) posting or sharing a post on social media about CCA. Multinomial logistic regression models examined correlates of CCA communications. Descriptive and injunctive social norms, barriers to CCA, and climate change distress were consistently significantly associated with engaging in the three CCA communication modalities in the prior month compared to never. This study's results suggest that talking with peers is the most common form of CCA communication, and is associated with social norms and distinct barriers to CCA. Organizations that address climate change should consider utilizing dialogical approaches to shift social norms related to CCA, and foster CCA communications and address barriers to CCA. [ABSTRACT FROM AUTHOR]

Over the past decade, a consensus has emerged among academics and policy makers that climate change could threaten the stability of banks, insurers, and the broader financial system. In response, regulators from around the world have begun implementing policies to mitigate emerging climate risks in the financial sector. The United States, however, lags significantly behind other countries in addressing such risks. This article argues that the United States' sluggishness in responding to climate‐related financial risk is problematic because the U.S. banking system is uniquely susceptible to climate change. The United States' vulnerability stems, in part, from a little‐known statutory provision that prohibits U.S. regulators from relying on external credit ratings in bank capital requirements. Because of this deviation from internationally accepted capital standards, when a credit rating agency downgrades a "dirty" company, U.S. banks that lend to that company need not compensate by maintaining a bigger capital cushion. Over time, this dynamic will likely incentivize "dirty" companies to borrow more from U.S. banks, intensifying the U.S. banking system's exposure to climate risks. This article contends that the United States must overcome this unusual weakness by taking bold steps to safeguard the domestic financial system from the climate crisis. [ABSTRACT FROM AUTHOR]

The Biden administration has revitalized the United States' climate agenda. Current research on the U.S. climate mitigation policies has predominantly focused on individual policies and legislative measures, demonstrating a lack of a comprehensive and systematic analysis. To address this gap, this study establishes a systematic analytical framework for US climate mitigation policies, including the "Vertical Policy Hierarchy - Horizontal Policy Path - Policy Instruments" dimensions, drawing upon first-hand policy data to thoroughly assess the U.S. climate mitigation policy system, pathways, instruments, and potential policy outcomes. The study finds that, (i) Concerning the vertical policy hierarchies based on the government's governance structure, the U.S. federal government has been proactive in advancing climate mitigation policies. However, the government faces multiple risks arising from various factors, including elections, public opinion, limited authority, frequent economic and social unrest, and the ever-shifting domestic and international political factors. These vulnerabilities may undermine the effectiveness of policies. The Congress also encounters certain challenges of significant fragmentation and influence from diverse economic and political factors, which poses challenges to the enactment of related environmental legislation. Moreover, the Supreme Court's climate litigation rulings tend to exhibit a conservative and highly politicized nature. (ii) In terms of the horizontal policy path, which is categorized into six major focus areas, the U.S. climate mitigation policies have made positive strides in the general sector, buildings sector, transport sector, and agriculture and forestry sector. However, challenges persist in the energy sector and industry and business sector. (iii) An analysis of 706 policy instruments indicates that Financial/Fiscal Mechanisms and Direct Investment are the primary means of implementing U.S. climate mitigation policies. Since President Biden assumed office, Regulatory Reform has emerged as a significant breakthrough, accompanied by the gradual adoption of Commercialization Mechanisms and Governance Mechanisms. However, Market-based Mechanisms have encountered challenges in their implementation at the federal level. (iv) An analysis of the potential effects of policy instruments indicates that institutional requirements are a primary consideration; policy design emphasizes environmental justice and equity. Many policies demonstrate positive outcomes in terms of environmental effectiveness, economic effectiveness, and innovation. Policies are also beneficial in improving people's livelihoods, reducing inflation, increasing employment, while also exhibiting positive synergies and enhancing competitiveness. Combining these results and issues, this paper also discusses prominent trends in the policy and offers recommendations for climate decision-making in the United States and other countries. [Display omitted] [ABSTRACT FROM AUTHOR]

Decarbonizing the energy system is critical for addressing climate change. Given the dominance of fossil fuels in the energy system, decarbonization requires rapid and significant industrial transition of the energy supply at scale. This includes explicit and coordinated plans not only for zero carbon phase‐in, but for fossil carbon phase‐out. Even very rapid decarbonization will likely take decades, leading to a medium‐term future where the conventional, fossil‐based energy system coexists with a new, zero‐carbon energy system. Each imposes operational constraints on the other: what we call the mid‐transition. Notably, this coexistence means that the new, zero‐carbon system will develop under fossil carbon system constraints. The mid‐transition will therefore likely require specific analytical metrics designed to support decision making under dynamic and uncertain conditions. Many aspects of transition will be felt, and shaped, directly by individuals because of our direct interactions with energy systems. Even rare missteps are likely to have significant and potentially system design‐relevant impacts on perception, political support, and implementation. Comparisons of the new system to the old system are likely to rest on experience of a world less affected by climate change, such that concerns about lower reliability, higher costs, and other challenges might be perceived as inherent to zero‐carbon systems, versus energy systems facing consequences of climate change and long‐term underinvestment. This review assesses and evaluates medium‐term challenges associated with the mid‐transition in the United States, emphasizing the need for explicit planning for joint and coordinated phase‐in and phase‐out. This article is categorized under: The Carbon Economy and Climate Mitigation > Decarbonizing Energy and/or Reducing Demand [ABSTRACT FROM AUTHOR]

The current study assessed emotional responses and emotion regulation strategies to the climate crisis, and their relationship to pro-environmental behaviour cross-sectionally using self-report online surveys. 1307 participants were recruited through convenience sampling from six European countries, alongside a distinct sample of 1040 participants representative of age, sex, and ethnicity in the United States. Our findings replicated the well-known association that stronger negative emotions to the climate crisis are associated with more pro-environmental behaviour. The relationship between climate emotions and pro-environmental behaviour was moderated by resignation in the US sample, by cognitive reappraisal and other-blame in the European sample and mediated by rumination in both samples. Furthermore, latent profiles of emotional responses were identified. In both samples, there was one distinct class demonstrating strong climate emotions, and a group with very low or no climate emotions (alongside with two/three groups with moderate emotional intensity in the European and the US samples, respectively). Findings also revealed that members of the emotional group were more likely to take climate action and tend to engage more in emotion regulation than the unemotional group. Our results highlight the crucial role of emotions and emotion regulation strategies in mitigating the climate crisis by taking pro-environmental action. • Negative climate emotions are linked with increased climate action. • Ruminating on climate change is associated with taking climate action. • Resignation moderates the link between negative climate emotions and climate action. • Shift of focus moderates the link between negative climate emotions and climate action. • Emotions are crucial in mitigating climate change by facilitating climate action. [ABSTRACT FROM AUTHOR]

This paper examines how the economic growth imperative not only drives climate change and created the conditions for the development and spread of the COVID-19 pandemic but is also the context for climate change inaction and ineffective responses to the pandemic. Focusing on the United States, the paper identifies pretenses for collective inaction on COVID-19 that are similar in content to familiar justifications for delay in climate action: (1) denialism, (2) individualism, and (3) techno-optimism. These justifications must be identified as strategies to maintain the status-quo and benefit the wealthy few while allowing avoidable human suffering and loss. Adequately addressing climate change and future pandemics requires overcoming these false narratives and transitioning to social conditions that are resilient, healthy, and sustainable – specifically conditions where social and ecological well-being are prioritized over economic growth for the sake of profit maximization. [ABSTRACT FROM AUTHOR]

On a warming planet, a key challenge natural resource managers face is protecting wildlife while mitigating climate change—as through forest carbon storage—to the greatest extent possible. But in some ecosystems, habitat restoration for imperiled species may be incompatible with maximizing carbon storage. For example, promoting early successional forest conditions does not maximize stand‐level carbon storage, whereas uniformly promoting high stocking or mature forest conditions in the name of carbon storage excludes species that require open or young stands. Here, we briefly review the literature regarding carbon and wildlife trade‐offs and then explore four case studies from the Northern Forest region of the United States. In each case, human activities have largely dampened the influence of natural disturbances; restoring or emulating these disturbances is typically required for habitat restoration even when doing so equates to less carbon storage at the stand level. We propose that applying a climate adaptation lens can help managers and planners navigate these trade‐offs and steer away from maladaptive practices that may ultimately reduce adaptive capacity. Instead, critically evaluating the consequences of stand‐level management actions on both carbon and wildlife can then facilitate landscape‐scale climate adaptation planning that supports a diversity of habitats alongside opportunities to invest in maximizing forest carbon. [ABSTRACT FROM AUTHOR]

Societal benefits from climate change mitigation accrue via multiple pathways. We examine the US impacts of emission changes on several factors that are affected by both climate and air quality responses. Nationwide benefits through midcentury stem primarily from air quality improvements, which are realized rapidly, and include human health, labor productivity, and crop yield benefits. Benefits from reduced heat exposure become large around 2060, thereafter often dominating over those from improved air quality. Monetized benefits are in the tens of trillions of dollars for avoided deaths and tens of billions for labor productivity and crop yield increases and reduced hospital expenditures. Total monetized benefits this century are dominated by health and are much larger than in previous analyses due to improved understanding of the human health impacts of exposure to both heat and air pollution. Benefit-cost ratios are therefore much larger than in prior studies, especially those that neglected clean air benefits. Specifically, benefits from clean air exceed costs in the first decade, whereas benefits from climate alone exceed costs in the latter half of the century. Furthermore, monetized US benefits largely stem from US emissions reductions. Increased emphasis on the localized, near-term air quality-related impacts would better align policies with societal benefits and, by reducing the mismatch between perception of climate as a risk distant in space and time and the need for rapid action to mitigate long-term climate change, might help increase acceptance of mitigation policies. [ABSTRACT FROM AUTHOR]

State and local climate action has played a prominent role in the global response to climate change. Rather than waiting for national action, states like California have surged ahead. This is not simply a U.S. phenomenon. Still, not all jurisdictions are engaged in emissions reductions, and some are actively recalcitrant. What prompts some state and local governments to take action while prompting others to resist? This Article makes several contributions to understanding state and local climate policies. First, prior efforts have generally had a U.S. focus. We broaden the scope of the inquiry to include the two leading Asian economies. Second, we make use of a jifty-state survey of recent state climate and energy initiatives in the United States rather than focusing on a few prominent jurisdictions like California. Third, rather than concentrating on activist jurisdictions, we discuss the full range of stances on energy policy, from the leadership of states like California in the United States and cities like Shenzhen in China to the resistance of some rural areas of the United States, China, and Japan to climate action. We identify important economic, demographic, and geographic drivers of climate and energy policies in these diverse jurisdictions. Finally, we propose a new way Of conceptualizing subnational climate action based on the peer production model used to create important digital resources. Like some open-source software and projects such as Wikipedia. important parts Of global climate policy have been constructed by sub-nationals through a self-organized, bottom-up effort. This kind of "peer production" has previously been described in the private sector, but it may play an underappreciated role in the sphere of public policy. [ABSTRACT FROM AUTHOR]

Climate change-induced migration is a rapidly increasing phenomenon estimated to affect millions of people in the coming decades. With increasing media coverage of climate migration, including within the United States, it is critical to understand how to effectively communicate about this issue. In two high-powered experiments of U.S. Democrats and Republicans (& leaners; Study 1: N = 1452; Study 2: N = 1873), we test the effects of fictional news coverage about domestic and international climate-induced migration on climate change and migration risk perceptions, warmth toward migrants, and policy support. We also tested whether including a personal story about a specific migrant alongside numerical trends could increase support for climate change mitigation and aiding potential migrants. Impacts on climate outcomes were minimal: in Study 1, those exposed to different message frames reported similar climate policy support and risk perception in Study 1, and, in Study 2, domestic (but not international) climate migration coverage slightly increased climate risk perceptions and marginally increased mitigation policy support compared to a no-message baseline. In both studies, international migration was perceived as riskier to Americans than domestic migration, and coverage of international migration heighted this perceived risk. Coverage of domestic climate migration, on the other hand, did not boost risk perceptions of that type of migration. Furthermore , coverage of international climate migration led to greater support for adaptation infrastructure to help potential migrants stay home but did not affect support for policies to help migration. Contrary to expectations, the inclusion of personal stories did not affect warmth toward migrants in either study. Political affiliation dominated associations with all climate change and migration outcomes, likely obscuring potential framing effects. These results suggest that coverage about climate-induced migration may face challenges in shifting entrenched public opinion and policy support. Communicators should be aware of the limitations of using this type of coverage to promote constructive actions to address climate change and migration. • Reactions to climate migration in the U.S. are highly polarized. • News of international climate migration heightens perceived migration risks. • Framing affected policy support for local climate adaptation more than relocation. • Climate migration coverage has minimal impact on climate beliefs or policy support. [ABSTRACT FROM AUTHOR]

• Climate action on the state level is dependent on political context (specifically, Republicanism)—an influence far less prominent on the local level. • At both state and local scales of governance, climate mitigation is somewhat more strongly influenced by power dynamics compared to climate adaptation. • State-level power dynamics best predict state climate action and, to a substantially weaker extent, combined state and local power dynamics best predict local climate action. • Power dynamics outweigh the influences of politics and climate risk on state and local climate action. American cities have played an increasingly critical role in advancing US climate change mitigation and adaptation. Subnational government support for these efforts, however, varies across social, political, economic, and biogeophysical contexts. While the influence of politics on US climate mitigation is well established, further research is required to identify barriers to—and discern complex influences on—US subnational climate action. This study examines the influences of power dynamics between public and private interests, political party affiliation within government and the public, and risk of climate impacts, on observed climate mitigation and adaptation efforts within 136 urban US cities and 33 states. The findings of this study shed light on the motivations of subnational governments to take climate action, and identify significant dynamics influencing the likelihood of key state or local government decision-makers to take climate action. [ABSTRACT FROM AUTHOR]

Although the scientific community has reached a consensus that anthropogenic climate change is a severe and pressing issue, climate change remains a contentious debate with the United States public. Through a survey (N = 273), we explored climate professionals' perspectives on their role and responsibility to promote climate change adaptation/mitigation strategies related to agroecosystems. They believed that climate professionals have a social responsibility to provide scientific input to both policymakers and the public. There was strong agreement that media, political, and public support is necessary for development, and near unanimous agreement for implementation, of climate change mitigation/adaptation strategies. This study highlights the climate professionals' perceptions of their responsibility to provide scientific input, but also demonstrates that they believe the responsibility does not rest solely on their shoulders. Further research should explore scientists' perceptions of their and others' policy roles and scientists' interactions with different influencers of adaptation/mitigation policy. [ABSTRACT FROM AUTHOR]

Prior research demonstrates widespread persistence of beliefs about climate change causes and risks that are arguably misconceptions. They include believing pollution causes climate change, believing ozone depletion causes climate change, the combination of these two "green beliefs," referred to as environmental problems, and believing natural climate variation significantly contributes to current climate trends. Each of these causal beliefs has the potential to weaken or divert support away from effective climate change risk mitigation policies. To assess this potential, we explore the nature and prevalence of these beliefs in the United States with a national sample of interviews (N = 77) and two national surveys (N = 1,013, N = 1,820), and apply regression and mediation analyses to explore whether they explain any of the variation in individuals' concern or support for policy to mitigate climate change. Adherence to these beliefs—which reflect a variety of misconceptions illustrated in the interviews—differs by political ideology but is common, with over a third of interviewees mentioning one or more. Controlling for general knowledge, political ideology, and other factors, misconceptions about environmental problems are still associated directly with support for climate change policies. On average adherence to the belief that environmental problems cause climate change is associated with a 25% higher probability of policy support. In contrast, believing natural climate variability is a major recent cause of climate change is associated with a 7% lower probability of supporting climate policy, even after controlling for political ideology and other knowledge about climate change. [ABSTRACT FROM AUTHOR]

Climate change is expected to alter the distributions of species around the world, but estimates of species' outcomes vary widely among competing climate scenarios. Where should conservation resources be directed to maximize expected conservation benefits given future climate uncertainty? Here, we explore this question by quantifying variation in fish species' distributions across future climate scenarios in the Red River basin south‐central United States. We modeled historical and future stream fish distributions using a suite of environmental covariates derived from high‐resolution hydrologic and climatic modeling of the basin. We quantified variation in outcomes for individual species across climate scenarios and across space, and identified hotspots of species loss by summing changes in probability of occurrence across species. Under all climate scenarios, we find that the distribution of most fish species in the Red River Basin will contract by 2050. However, the variability across climate scenarios was more than 10 times higher for some species than for others. Despite this uncertainty in outcomes for individual species, hotspots of species loss tended to occur in the same portions of the basin across all climate scenarios. We also find that the most common species are projected to experience the greatest range contractions, underscoring the need for directing conservation resources toward both common and rare species. Our results suggest that while it may be difficult to predict which species will be most impacted by climate change, it may nevertheless be possible to identify spatial priorities for climate mitigation actions that are robust to future climate uncertainty. These findings are likely to be generalizable to other ecosystems around the world where future climate conditions follow prevailing historical patterns of key environmental covariates. [ABSTRACT FROM AUTHOR]

The United States is experiencing growing impacts of climate change but currently receives a limited policy response from its national leadership. Within this policy void, many state governments are stepping up and taking action on adaptation planning. Yet we know little about why some states adopt State Adaptation Plans (SAPs), while others do not. This article investigates factors that predict the emergence of SAPs, both in terms of policy adoption and policy intensity (goal ambitiousness). Applying the diffusion of innovation theory, I consider the relative influence of internal state characteristics, regional pressures, and test for conditional effects between government ideologies and severity of the problem. The results show interesting differences between predictors that influence policy adoption and ambitiousness. States are more motivated to adopt a policy when faced with greater climate vulnerability, have more liberal citizenry, and where governments have crossed policy hurdles by previously passing mitigation plans. The intensity of policies and goal setting, moreover, is more likely to be driven by interest group politics and diffuse through policy learning or sharing information among neighboring states in Environmental Protection Agency regions. These findings support an emerging scholarship that uses more complex dependent variables in policy analysis. These variables have the potential to differentiate symbolic from substantive policies and capture finer information about predictors of importance. [ABSTRACT FROM AUTHOR]

Land‐use/cover change (LUCC) is an important driver of environmental change, occurring at the same time as, and often interacting with, global climate change. Reforestation and deforestation have been critical aspects of LUCC over the past two centuries and are widely studied for their potential to perturb the global carbon cycle. More recently, there has been keen interest in understanding the extent to which reforestation affects terrestrial energy cycling and thus surface temperature directly by altering surface physical properties (e.g., albedo and emissivity) and land–atmosphere energy exchange. The impacts of reforestation on land surface temperature and their mechanisms are relatively well understood in tropical and boreal climates, but the effects of reforestation on warming and/or cooling in temperate zones are less certain. This study is designed to elucidate the biophysical mechanisms that link land cover and surface temperature in temperate ecosystems. To achieve this goal, we used data from six paired eddy‐covariance towers over co‐located forests and grasslands in the temperate eastern United States, where radiation components, latent and sensible heat fluxes, and meteorological conditions were measured. The results show that, at the annual time scale, the surface of the forests is 1–2°C cooler than grasslands, indicating a substantial cooling effect of reforestation. The enhanced latent and sensible heat fluxes of forests have an average cooling effect of −2.5°C, which offsets the net warming effect (+1.5°C) of albedo warming (+2.3°C) and emissivity cooling effect (−0.8°C) associated with surface properties. Additional daytime cooling over forests is driven by local feedbacks to incoming radiation. We further show that the forest cooling effect is most pronounced when land surface temperature is higher, often exceeding −5°C. Our results contribute important observational evidence that reforestation in the temperate zone offers opportunities for local climate mitigation and adaptation. [ABSTRACT FROM AUTHOR]

The article explores the implications of climate change for public welfare and fiscal policy in the U.S. through the use of the Climate Optimization Model of the Economy and Taxation. Topics discussed include the implication of climate change as a fiscal risk for governments, impact of climate change on the costs of providing government services, and the possible increase in the welfare costs of unmitigated climate change.

Exposure to high ambient temperatures is an important cause of avoidable, premature death that may become more prevalent under climate change. Though extensive epidemiological data are available in the United States, they are largely limited to select large cities, and hence, most projections estimate the potential impact of future warming on a subset of the U.S. population. Here we utilize evaluations of the relative risk of premature death associated with temperature in 10 U.S. cities spanning a wide range of climate conditions to develop a generalized risk function. We first evaluate the performance of this generalized function, which introduces substantial biases at the individual city level but performs well at the large scale. We then apply this function to estimate the impacts of projected climate change on heat‐related nationwide U.S. deaths under a range of scenarios. During the current decade, there are 12,000 (95% confidence interval 7,400–16,500) premature deaths annually in the contiguous United States, much larger than most estimates based on totals for select individual cities. These values increase by 97,000 (60,000–134,000) under the high‐warming Representative Concentration Pathway (RCP) 8.5 scenario and by 36,000 (22,000–50,000) under the moderate RCP4.5 scenario by 2100, whereas they remain statistically unchanged under the aggressive mitigation scenario RCP2.6. These results include estimates of adaptation that reduce impacts by ~40–45% as well as population increases that roughly offset adaptation. The results suggest that the degree of climate change mitigation will have important health impacts on Americans. Key Points: We develop a generalized risk function from U.S. epidemiological data to quantify nationwide heat‐related premature deathsWe find ~12,000 premature deaths annually in the contiguous United States during the 2010sProjected deaths rise to ~110,000 and ~50,000 year−1 under high‐ and moderate‐warming scenarios, respectively, including population growth [ABSTRACT FROM AUTHOR]

Forest carbon sequestration via forest preservation can be a viable climate change mitigation strategy. Here, we identify forests in the western conterminous United States with high potential carbon sequestration and low vulnerability to future drought and fire, as simulated using the Community Land Model and two high carbon emission scenario (RCP 8.5) climate models. High‐productivity, low‐vulnerability forests have the potential to sequester up to 5,450 Tg CO2 equivalent (1,485 Tg C) by 2099, which is up to 20% of the global mitigation potential previously identified for all temperate and boreal forests, or up to ~6 yr of current regional fossil fuel emissions. Additionally, these forests currently have high above‐ and belowground carbon density, high tree species richness, and a high proportion of critical habitat for endangered vertebrate species, indicating a strong potential to support biodiversity into the future and promote ecosystem resilience to climate change. We stress that some forest lands have low carbon sequestration potential but high biodiversity, underscoring the need to consider multiple criteria when designing a land preservation portfolio. Our work demonstrates how process models and ecological criteria can be used to prioritize landscape preservation for mitigating greenhouse gas emissions and preserving biodiversity in a rapidly changing climate. [ABSTRACT FROM AUTHOR]

Variations in meteorology associated with climate change can impact fine particulate matter (PM2.5) pollution by affecting natural emissions, atmospheric chemistry, and pollutant transport. However, substantial discrepancies exist among model‐based projections of PM2.5 impacts driven by anthropogenic climate change. Natural variability can significantly contribute to the uncertainty in these estimates. Using a large ensemble of climate and atmospheric chemistry simulations, we evaluate the influence of natural variability on projections of climate change impacts on PM2.5 pollution in the United States. We find that natural variability in simulated PM2.5 can be comparable or larger than reported estimates of anthropogenic‐induced climate impacts. Relative to mean concentrations, the variability in projected PM2.5 climate impacts can also exceed that of ozone impacts. Based on our projections, we recommend that analyses aiming to isolate the effect climate change on PM2.5 use 10 years or more of modeling to capture the internal variability in air quality and increase confidence that the anthropogenic‐forced effect is differentiated from the noise introduced by natural variability. Projections at a regional scale or under greenhouse gas mitigation scenarios can require additional modeling to attribute impacts to climate change. Adequately considering natural variability can be an important step toward explaining the inconsistencies in estimates of climate‐induced impacts on PM2.5. Improved treatment of natural variability through extended modeling lengths or initial condition ensembles can reduce uncertainty in air quality projections and improve assessments of climate policy risks and benefits. Plain Language Summary: Climate change can worsen air pollution caused by small particles in the atmosphere as it alters temperature, precipitation, and other weather variables. Models have been used to project the effects climate change can have on airborne particle concentrations. However, natural year‐to‐year and longer‐term variations in weather can make it difficult to estimate the impacts specifically caused by human forces. In this study, we use a large set of climate and air quality simulations to assess the effect of natural variability in model‐based projections of climate change impacts on air pollution over the United States. Our results show that natural variations in predictions of climate change effects on fine particle levels can be significant. We recommend that projections use longer simulation lengths than typically applied, 10 years or more, in order to filter out this natural variability and better reflect the effect of human‐caused climate change on particle pollution. Natural variability can also make it challenging to confidently project human‐caused climate impacts in some regions or if efforts are taken to reduce greenhouse gas emissions. By using larger modeling lengths or simulation sets, projections of climate change impacts on air pollution and climate policy benefit analyses can be improved. Key Points: Natural variability adds uncertainty to simulations of anthropogenic climate change effects on fine particulate matter pollutionThe use of decadal simulations or ensembles can increase confidence in projections of the impacts on particulate matterRegional‐scale and climate‐stabilization projections may require larger simulation lengths to identify an anthropogenic‐forced signal [ABSTRACT FROM AUTHOR]

Coastal marshes are important carbon sinks facing serious threats from climatic stressors. Current research reveals that the growth of individual marsh plants is susceptible to a changing climate, but the responses of different marsh systems at a landscape scale are less clear. Here, we document the multi‐decadal changes in the phenology and the area of the extensive coastal marshes in Louisiana, USA, a representative of coastal ecosystems around the world that currently experiencing sea‐level rise, temperature warming, and atmospheric CO2 increase. The phenological records are constructed using the longest continuous satellite‐based record of the Earth's ecosystems, the Landsat data, and an advanced modeling technique, the nonlinear mixed model. We find that the length of the growing seasons of the intermediate and brackish marshes increased concomitantly with the atmospheric CO2 concentration over the last 30 years, and predict that such changes will continue and accelerate in the future. These phenological changes suggest a potential increase in CO2 uptake and thus a negative feedback mechanism to climate change. The areas of the freshwater and intermediate marshes were stable over the period studied, but the areas of the brackish and saline marshes decreased substantially, suggesting ecosystem instability and carbon storage loss under the anticipated sea‐level rise. The marshes' phenological shifts portend their potentially critical role in climate mitigation, and the different responses among systems shed light on the underlying mechanisms of such changes. [ABSTRACT FROM AUTHOR]

The article explores how Americans' view global warming. It mentions the view of about half of Americans on climate change as a personal risk and the impact of limited perception of the risks and social consensus on climate change solutions on Americans' views on climate change. It also offers data showing the trends in global warming beliefs and risk perceptions of Americans,political party, and generations as well as the climate change mitigation policy support from 2008 to 2017.

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A growing body of research demonstrates that believing action to reduce the risks of climate change is both possible (self‐efficacy) and effective (response efficacy) is essential to motivate and sustain risk mitigation efforts. Despite this potentially critical role of efficacy beliefs, measures and their use vary wildly in climate change risk perception and communication research, making it hard to compare and learn from efficacy studies. To address this problem and advance our understanding of efficacy beliefs, this article makes three contributions. First, we present a theoretically motivated approach to measuring climate change mitigation efficacy, in light of diverse proposed, perceived, and previously researched strategies. Second, we test this in two national survey samples (Amazon's Mechanical Turk N = 405, GfK Knowledge Panel N = 1,820), demonstrating largely coherent beliefs by level of action and discrimination between types of efficacy. Four additive efficacy scales emerge: personal self‐efficacy, personal response efficacy, government and collective self‐efficacy, and government and collective response efficacy. Third, we employ the resulting efficacy scales in mediation models to test how well efficacy beliefs predict climate change policy support, controlling for specific knowledge, risk perceptions, and ideology, and allowing for mediation by concern. Concern fully mediates the relatively strong effects of perceived risk on policy support, but only partly mediates efficacy beliefs. Stronger government and collective response efficacy beliefs and personal self‐efficacy beliefs are both directly and indirectly associated with greater support for reducing the risks of climate change, even after controlling for ideology and causal beliefs about climate change. [ABSTRACT FROM AUTHOR]

Renewable portfolio standards (RPS) are an important policy tool for reducing carbon emissions and advancing the global shift toward renewable energy. As the U.S. federal government backs away from commitments to reduce greenhouse gas emissions, subnational governments play an increasingly important role in mitigating climate change. In June 2015, Hawaii became the first state in the United States to adopt a 100% RPS. Through understanding the conditions that gave rise to Hawaii's RPS, policy actors will be better informed as they navigate policy processes in other states and jurisdictions. This study uses Kingdon's Multiple Streams Framework (MSF) to explore the policy process that led to Hawaii's 100% RPS. Data were collected during the summer of 2016 via interviews with 25 key policy actors and informants in Hawaii. Expectations based on the MSF are confirmed, and the results suggest factors that might be included or explored in future studies of RPS adoption. [ABSTRACT FROM AUTHOR]