US Climate Research Articles

Impact of switchable roof insulation on energy performance of US residential buildings

In the analysis described in this paper, the energy efficiency benefits of switchable insulation systems (SIS) are evaluated when applied to roofs for US residential buildings. Unlike conventional static insulations, SISs can change their thermal properties based on control strategies to achieve desired objectives. In this analysis, SISs applied to roofs are controlled to minimize heating and cooling thermal loads for US housing units. Specifically, 2-step controls are utilized to switch the R-value of SISs between low and high levels depending on outdoor and indoor thermal interactions in order to reduce heating and cooling needs while maintaining thermal comfort within a prototypical one-story home located in different US climates. The analysis results indicate that SISs can significantly reduce energy consumption for heating and cooling systems. The energy efficiency effectiveness of SISs is found to increase for high reflective roofs and for high difference between the high and low R-values especially to reduce cooling energy needs for mild and heating dominated climates. In particular, the deployment of 2-step control strategies operating SISs can reduce annual energy use by up to 44% for space cooling and up to 17% for space heating.

Energy savings of retrofitting residential buildings with variable air volume systems across different climates

Residential buildings account for 20% of total energy consumption in the United States, with single family detached houses accounting for 77% of residential site energy consumption. A multizone variable air volume (VAV) system can save energy by directing conditioned air to different occupied zones in the home as needed. While multizone VAV systems in single family houses have been economically inaccessible in the past, recent technological developments in building automation controls and the Internet of Things (IoT) can enable homeowners to retrofit their existing HVAC systems into VAV systems, warranting further investigation into the energy savings potential of such systems. Past residential VAV system research mostly involved simulations and measurements of singular case study houses over short periods of time. In this study, representative energy models of two different house sizes, with estimates of individual room sizes, were developed to expand on those case studies and examine energy savings for single family homes across seven US climate zones over an entire year. Average size house models report 24%–42% source energy savings while large house size models report 18%–35% source energy savings, with houses in cooling dominant climate saving relatively more. Annual energy cost savings range from 24% to 42% for average size house models and 18%–35% for large size house models. These results indicate greater energy savings potential for single family homeowners considering VAV retrofits in cooling climates and areas with higher cost of electricity. Projected present value of energy cost savings over a typical home ownership period similarly yielded favorability for houses in cooling dominant climates, but were impacted by energy price changes over time. Future research should focus on the payback analyses of single family VAV system implementations and its sensitivity to occupant behavior. The details of the representative energy models, with estimates of room sizes and occupancy schedules, are provided for future studies that focus on multizone energy saving strategies.

The rigorous adjustment of the global mean sea level budget during 2005–2015

Global mean sea level budget is rigorously adjusted during the period 2005–2015. The emphasis is to provide the best estimates for the linear rates of changes (trends) of the global mean sea level budget components during this period subject to the constraint: Earth's hydrosphere conserves water. The newly simultaneously adjusted trends of the budget components suggest a larger correction for the global mean sea level trend implicated by the other budget components' trends under the budget constraint. The simultaneous estimation of the linear trends of the budget components subject to the constraint for closure improves their uncertainties and enables a holistic assessment of the global mean sea budget, which has implications for future sea level science studies, including the future Intergovernmental Panel on Climate Change (IPCC) Assessment Reports, and the US Climate Assessment Reports.

A Stochastic Approach in Modeling of Regional Atmospheric CO2 in the United States

Global warming is a function of two main contributable entities in the atmosphere, carbon dioxide, and atmospheric temperature. The objective of this study is to develop a statistical model using actual fossil fuel carbon dioxide emissions data from the United States to predict relative probability of rate of change in fossil fuels carbon dioxide emissions from nine US climate regions using transition modeling. The sensitivity of these transition probabilities to five sectors, that are the commercial, industrial, residential, transportation, and electric power sector, is also investigated for all nine US climate regions. The present study also suggests that the US government should be developing regional policies to control fossil fuel carbon dioxide emissions that will be more effective in addressing the subject problem.

Cultural responses to loss and grief among Black Americans: Theory and practice implications for clinicians

Dying, death, and grief are universal human experiences that are impacted by cultural values and beliefs. We provide service providers a context from which to consider the importance of spirituality and religiosity in the grief process and the variances in grief practices that exist within the Black community. This knowledge can serve as a catalyst for developing culturally appropriate interventions for Black people aimed at helping them to more effectively cope with grief and further enabling them to thrive rather than merely survive a sociopolitical US climate that is laden with grief producing experiences.

Eddy covariance measurements of carbon dioxide and water fluxes in US mid-south cotton production

An eddy covariance (EC) system was used over a production-scale, US mid-south cotton field in order to improve understanding of carbon and water flux dynamics in cotton production. Measurement outcomes of NEE and ET from agricultural cropping systems in the humid US mid-south may differ from measurements made in arid production regions due to variation in precipitation, relative humidity, and cloud cover. Local measurements are needed for timely irrigation water management decisions and to assess their impact on the carbon cycle. Measurements were made in a 63-ha field in Northeast Arkansas in the 2016 and 2017 growing seasons (May-October). Average daily NEE during the growing season was driven largely by gross primary production (GPP) measured at -1.80 ± 0.26 g C m−2 d-1 ranging between -13.5 and 2.4 g m−2 d-1 during 2016 and -1.97 ± 0.26 g C m−2 d-1 ranging between -11.1 and 5.9 g m−2 d-1 during 2017. Across both years the average daily GPP during the growing season was 7.65 ± 0.45 g C m−2 d-1 during 2016 and 8.33 ± 0.37 g C m−2 d-1 during 2017. GPP was lowest during emergence and post-harvest and highest from the first week of flowering (FF) stage to about 3 weeks after cutout (cessation of vegetative expansion and production of new fruiting sites). Measured ET was lowest early and late in the season, and highest from FF until cutout. Across both seasons, average ET was 3.5 ± 0.1 mm d-1, more specifically 3.3 ± 0.1 mm d-1 during 2016 and 3.6 ± 0.1 mm d-1 during 2017. Peak water use was 7.6 mm d-1 during both growing seasons. Measured ET values were similar to results from lysimeter studies conducted in humid southeastern US climates, but lower than those observed in studies in arid regions. The water use efficiency of harvest yield per evapotranspiration flux was 0.26 kg lint cotton m-3 water and 0.34 kg lint m-3 water in 2016 and 2017, respectively which 1.5–2 times those of other studies, likely due to higher yields and lower evapotranspiration measured in this study. The findings suggest that US mid-south cotton production should continue to be managed differently than other more arid US cotton production regions.

The Future of US Carbon-Pricing Policy

There is widespread agreement among economists—and a diverse set of other policy analysts—that at least in the long run, an economy-wide carbon-pricing system will be an essential element of any national policy that can achieve meaningful reductions of CO2 emissions cost-effectively in the United States. There is less agreement, however, among economists and others in the policy community regarding the choice of specific carbon-pricing policy instrument, with some supporting carbon taxes and others favoring cap-and-trade mechanisms. This prompts two important questions: How do the two major approaches to carbon pricing compare on relevant dimensions, including but not limited to efficiency, cost-effectiveness, and distributional equity? And which of the two approaches is more likely to be adopted in the future in the United States? This paper addresses these questions by drawing on both normative and positive theories of policy instrument choice as they apply to US climate change policy and draws extensively on relevant empirical evidence. The paper concludes with a look at the path ahead, including an assessment of how the two carbon-pricing instruments can be made more politically acceptable.

A statistical protocol for a holistic adjustment of global sea level budget

Abstract Current studies in global mean sea level, GMSL, studies assess the closure/misclosure of the GMSL budget components and their uncertainties. Because Earth’s hydrosphere conserves water, a closed global mean sea level budget with a consistent set of estimates and their statistics is necessary. An unclosed budget means that there are problems to be addressed such as biases in the budget components, unreliable error statistics about the estimates, unknown or known but unmodeled budget components. In a misclosed global mean sea level budget, as practiced in recent studies, the trend estimates for the budget components and their errors account only for the anomalies of each budget component in isolation. On the other hand, the trend of each series must consider the trends of the other series in tandem such that the global mean sea level budget is closed for a holistic assessment, which can only be achieved by adjusting global mean sea level budget components simultaneously. In this study, we demonstrate a statistical protocol to ameliorate this deficiency, which potentially have implications for future sea level science studies, including the future Intergovernmental Panel on Climate Change (IPCC) Assessment Reports, and the US Climate Assessment Reports.

A Sociology of Failure: Migration and Narrative Method in US Climate Fiction

A Sociology of Failure: Migration and Narrative Method in US Climate Fiction

Decadal and Interannual Variability of Persistent Heavy Rainfall Events over the Middle and Lower Reaches of the Yangtze River Valley

This study investigates the relationship between the anomalous atmospheric circulation pattern and summertime persistent heavy rainfall (PHR) over the middle and lower reaches of the Yangtze River valley (MLYRV) on the decadal and interannual timescales. Based on the gridded daily rainfall data of the US Climate Prediction Center, the PHR events on grid-point and the regional PHR events considering both the area of PHR and regionally averaged rainfall intensity are identified over the MLYRV during the summers of 1979–2017. A PHR index (PHRI) is defined, to describe the variability of summertime PHR event number over the MLYRV. The PHRI is then divided into the decadal and interannual components. Further analysis reveals that the decadal PHR events are closely related to anomalous precipitation, intensified vertical motion, and strengthened upper-level divergence over southern China, as well as an anomalous anticyclone over the western Pacific transporting more water vapor from the South China Sea (SCS) to southern China. As for the interannual component, the above pattern still co-exists but over a narrow region around the MLYRV. By choosing the years in which the decadal and interannual components of the PHRI are simultaneously positive (SP) or negative (SN), the features of regional PHR events in SP and SN years are analyzed, respectively. The results show that there are more regional PHR events in SP years with enhanced intensity and larger affected areas compared with those in SN years. Meanwhile, the zonal oscillations of the South Asian high (SAH) and the western Pacific subtropical high (WPSH) during the regional PHR events demonstrate a better regularity in SP years than those in SN years.

The development of partisan polarization over the Green New Deal

In early 2019, a US climate change and economic renewal policy proposal called the Green New Deal (GND)1 rose from obscurity to national prominence in just four months. This situation created a natural field experiment in which to study the emergence of partisan polarization. Here, we report findings from two nationally representative surveys of registered US voters that measured familiarity with and support for the GND shortly before and after the issue entered the national spotlight. Initially, there was low public awareness of the GND but majority support for it across party lines. Four months later, voters had become much more familiar with the GND and partisan polarization had increased significantly due to a sharp decrease in support among Republicans. In fact, Republicans who had heard the most about the GND were the least likely to support it. In contrast, support for the GND remained high among Democrats, and did not vary substantially across degrees of familiarity. We also identify a likely mechanism: a ‘Fox News effect’. That is, among Republicans, Fox News viewing was a significant predictor of both familiarity with the GND and opposition to it, even when controlling for alternative explanations. Opinions on climate policy in the United States are politically polarized. Here, survey research shows that opinion polarization on the Green New Deal developed rapidly due to decreasing support among Republicans, which was associated with exposure to conservative media and increasing familiarity with the policy.

Probabilistic assessment and projections of US weather and climate risks and economic damages

Weather and climate extremes cause significant economic damages and fatalities. Over the last few decades, the frequency of these disasters and their economic damages have significantly increased in the USA. The prediction of the future evolution of these damages and their relation to global warming and US economic growth is essential for deciding on cost-efficient mitigation pathways. Here we show using a probabilistic extreme value statistics framework that both the increase in US Gross Domestic Product per capita and global warming are significant covariates in probabilistically modeling the increase in economic damages. We also provide evidence that the Pacific Decadal Oscillation affects the number of fatalities. Using the Intergovernmental Panel on Climate Change scenarios, we estimate the potential future economic risks. We find that by 2060, the extreme risks (as measured by 200-year effective return level) will have increased by 3–5.4 times. The damage costs due to extreme risks are projected to be between 0.1 and 0.7% of US Gross Domestic Product by 2060 and could reach 5–16% by 2100.

Climate change as catastrophe or opportunity? Climate change framing and implications for water and climate governance in a drought-prone region

Given recent events in US climate policy, such as the US withdrawal from the Paris Agreement, understanding local (e.g., city and state) efforts to address climate change is increasingly imperative. Climate change–framing research has shown that people are motivated or deterred by different framing of issues in policy documents and other discourse. Considering this, there is a dearth of understanding of framing decisions in climate change–related policy documents that often inform how different levels of government communicate about and act to address climate change. We contribute a content analysis of framing in climate change–related policy documents tied to three western US cities/states (Phoenix, AZ; Denver, CO; Las Vegas, NV) that are particularly vulnerable to climate change. We discover that climate change is most frequently framed in terms of negatives/losses, both in water-related and climate change documents. Other common frames differed between the water-related and climate change–specific documents. The practical implications of climate change framing decisions are discussed in the context of recent political events in the United States. We emphasize the significance of understanding how local level actors frame climate change, as researchers and government officials have acknowledged the burden of responding to climate change progressively falls to local actors. We call for increased research on framing decisions and their connections to the perceived solution space, or suite of possible actions, to strengthen efforts by local actors to contribute to addressing climate change generally and to sustainably govern water resources specifically.

Trump, US climate politics, and the evolving pattern of global climate governance

ABSTRACTThis paper argues that the Trump administration’s position on climate change should be understood more in terms of continuity than disjuncture. It develops this argument in four principal ways. First, it situates Trump in the US’s paradoxical relationship to the UNFCCC, as a would-be leader that struggles to commit itself to substantive action, and the evolving geopolitics within the UNFCCC. Second, the paper focuses on an on-going struggle between pro-fossil fuel interests and a ‘decarbonising’ bloc, interpreting Trump (like George W. Bush) as a pro-fossil fuel backlash. Third, it explores the pattern of climate politics within the US, where stalemate in Congress has been often offset by action at the state, city, and corporate levels. Fourth, it should be understood in relation to the emergence of a ‘global climate governance complex’, where the UNFCCC has to be understood in relation to multilevel and transnational governance initiatives on climate change.

Echo chambers in climate science

To date, echo chambers in American climate politics have been found to focus on the climate-related policy instrument that is under review. In this paper, we explore how echo chambers change over time, integrating data collected on the federal climate policy network after the first 100 days of the Trump Administration had passed with data collected during two periods during the Obama Administration. We employ Exponential Random Graph (ERG) models to test for the similarity and differences over time in the top policy actors working on the issue during each time period. We then compare the newer findings from 2017 to previous work on data from 2010 and 2016. We find that echo chambers continue to play a significant role in the network of information exchange among policy elites and in the adoption of new information sources over time. In contrast to previous findings, however, where echo chambers centered on specific policy instruments—a binding international commitment to emission reductions or the Obama Administration’s Clean Power Plan—opinion regarding whether or not climate change is caused by humans (i.e. is anthropogenic) has become the central organizing force behind echo chambers in the US climate policy network. These results provide new empirical evidence that ideological polarization drives the selection of expert information in the debate around climate politics. Moreover, our results show how misinformation diffuses among political elites working on the issue of climate change.

Analysis of multi-step control strategies for dynamic insulation systems

Dynamic Insulation Materials (DIMs) present an opportunity to reduce the energy consumption of buildings by allowing heat transfer through the envelope at times when it is beneficial. Studies in the past have investigated a binary R-value control in which the thermal resistance of the wall is either “on” or “off. This study attempts to improve on this control strategy by maximizing the amount of beneficial heat transfer through the envelope using wall surface temperatures, the heating/cooling set-point temperature, and the temperature in the middle of the wall as parameters. It is found that adding a period during which the R-value of the wall can vary continuously within a defined range has the potential to modestly decrease the heating and cooling energy consumption. However, it is found that the most energy savings can be achieved by using a 2-step operation with settings slightly modified from previous studies. For a parametric analysis specific to a residential building in Golden, Colorado, the optimized operation mode produced heating energy savings of 9.3% and cooling energy savings of 21.0% relative to static RSI-3.8 insulation. Moreover, a parametric analysis was conducted to extrapolate the findings to multiple US cities with different climate zones. It is found that the optimized operation mode offers some energy savings for residential buildings in all US climates, though the extent of the savings and the optimized parameters are dependent on climate. Specifically, climates with low cooling degree-days have the potential for a higher reduction of cooling energy up to 35%, while climates with low heating degree-days are found to have the potential for a significant decrease in heating energy of over 80% relative to static insulation.

Strategic Gestures in Bill McKibben's Climate Change Rhetoric

Although Bill McKibben is widely recognized as one of the leading strategists of the US climate change movement, several observers identify significant limitations to his approach to climate advocacy and politics. These criticisms are based on his reliance upon “symbolic gestures,” such as campaigns to promote fossil fuel divestment and stop fossil fuel infrastructure construction. In this essay we reconsider McKibben’s work, drawing specifically on his speeches given from 2013-2016 in support of the fossil fuel divestment campaign and campaigns attempting to block the construction of fossil fuel infrastructure, in order to show how McKibben’s strategic orientation is grounded in a politics of gesture. His speeches provide a model for how to reconceive gestures and assemble them for political ends. Beyond the case of McKibben our analysis contributes the concept of strategic gestures to identify and theorize social movement interventions that have significant symbolic and material consequences.

Representation of the Madden–Julian Oscillation in CAMS-CSM

The Madden–Julian Oscillation (MJO) has a significant impact on global weather and climate and can be used as a predictability resource in extended-term forecasting. We evaluate the ability of the Chinese Academy of Meteorological Sciences Climate System Model (CAMS-CSM) to represent the MJO by using the diagnostic method proposed by the US Climate Variability and Predictability Program (CLIVAR) MJO Working Group (MJOWG). In general, the model simulates some major characteristics of MJO well, such as the seasonality characteristics and geographical dependence, the intensity of intraseasonal variability (ISV), dominant periodicity, propagation characteristics, coherence between outgoing longwave radiation (OLR) and wind, and life cycle of MJO signals. However, there are a few biases in the model when compared with observational/reanalyzed data. These include an overestimate of precipitation in the convergence zone of the North and South Pacific, a slightly weaker eastward propagation, and a shift in the dominant periodicity toward lower frequencies with slower speeds of eastward propagation. The model gives a poor simulation of the northward propagation of MJO in summer and shows less coherence between the MJO convection and wind. The role of moistening in the planetary boundary layer (PBL) in the eastward/northward propagation of MJO was also explored. An accurate representation of the vertical titling structure of moisture anomalies in CAMS-CSM leads to moistening of the PBL ahead of convection, which accounts for the eastward/northward propagation of MJO. Poor simulation of the vertical structure of the wind and moisture anomalies in the western Pacific leads to a poor simulation of the northward propagation of MJO in this area. Budget analysis of the PBL integral moisture anomalies shows that the model gives a good simulation of the moisture charging process ahead of MJO convection and that the zonal advection of moisture convergence term has a primary role in the detour of MJO over the Maritime Continent.

Tradeoffs in US dairy manure greenhouse gas emissions, productivity, climate, and manure management strategies

The United States is the largest supplier of dairy products globally, making it an important focus for environmental, economic, and societal outcomes. Increasingly greenhouse gases (GHGs) have become an area of focus for the industry, as industry groups have set their own goals to improve environmental impacts. A significant portion of dairy GHG emissions come from manure management, which can vary considerably by farm and region. Here we explore how the adoption and use of six common manure management strategies (MMS) have changed over a recent 12-year period, and how this relates to milk production, climate, and manure GHGs. Using data from the United States Department of Agriculture, the Environmental Protection Agency, and the National Oceanic and Atmospheric Administration across all fifty states, we find that overall US dairy manure management GHG emission intensity (CO2e per kg of milk produced) has increased 18% between 2003 and 2014, which is associated with an increase in adoption of liquid and anaerobic MMS. However, we also find that these systems are positively associated with higher productivity: nationally, total milk production grew by 21.0%, while the cow herd inventory grew by just 1.9%, an increase of 18.7% in per-cow milk production over the study period. We find clear regional adoption of certain kinds of MMS, which relate in many cases to temperature and rainfall. We discuss why these shifts may have occurred as a result of economic and policy drivers, including the shift towards these MMS for compliance with new water quality policies in the past decade, highlighting the tradeoffs that exist in on-farm decision-making. We provide some potential strategies to reduce GHG emissions in these systems while simultaneously considering water quality and other potential tradeoffs. We suggest that transitioning to some of these strategies requires additional research to better understand farmer decision-making as it relates to MMS, a currently understudied topic.

Are there periodically collapsing bubble behaviours in the global coffee market?

ABSTRACTThis paper investigates price bubbles in the global coffee market using the generalised supremum augmented Dickey-Fuller test. This approach can recognise multiple bubbles and date their origination and termination. The empirical results show that three bubbles existed in the coffee market from January 1990 to September 2017, during which the coffee price deviated from its fundamental value. Mismatch between supply and demand, speculation, US dollar fluctuations and climate change are applied to explain these bubbles. Corresponding policies, such as the prevention of pests and disease, emergency assistance, market structure improvement and recognition of US dollar fluctuations, should be emphasised to relieve the negative impacts of excessive coffee price volatility.