The death spiral of coal in the U.S.: will changes in U.S. Policy turn the tide?

ABSTRACT

The administration of U.S. President Donald Trump has promised to stop the ongoing spiralling down of the U.S. coal industry. We discuss the origins of the decline and assess the effects of policy interventions by the Trump administration. We find that, with fierce competition from natural gas and renewables, a further decrease of coal consumption must be expected by the old and inefficient U.S. coal-fired electricity generation fleet. By contrast, we consider the overly optimistic (for coal producers) view of the U.S. Energy Information Agency, and test whether the tide for the U.S. coal industry could turn as a result of three potential support measures: (i) revoking the Clean Power Plan (CPP); (ii) facilitating access to the booming Asian market; and (iii) enhanced support for Carbon Capture, Transport and Storage (CCTS) technology. We investigate the short-term and long-term effects on U.S. coal production using a comprehensive partial equilibrium model of the world steam coal market, COALMOD-World (Holz, Haftendorn, Mendelevitch, & von Hirschhausen, 2016). We find that revoking the CPP could stop the downward trend of steam coal consumption in the U.S., but even allowing for additional exports, will not lead to a return of U.S. coal production to the levels of the 2000s, that is, over 900?Mt per year. When global steam coal use is aligned with the 2°C climate target, U.S. steam coal production drops to around 100?Mt per year by 2030 and below 50?Mt by 2050, even if CCTS is available and exports via the U.S. West Coast is possible.

Key policy insights

• Declining U.S. coal use is primarily caused by competition from natural gas and renewables not by environmental regulation of the coal sector.

• Without substantial policy support, U.S. coal-fired generation capacity will continue to decline rapidly.

• Revoking the Clean Power Plan will lead to about one eighth higher U.S. coal production in the next years.

• Carbon Capture, Transport and Storage does not prevent the rapid decline of coal use required under stringent climate policy.

• Even in the most extreme pro-coal scenarios with additional export possibilities, U.S. coal production will not return to its pre-2010 levels.

     

The tidal jet in Rupert‐Holberg inlet,B.C.

Abstract

Observations of the tidal jet issuing from Quatsino Narrows into Rupert‐Holberg Inlet, B.C. are discussed. Two types of flow are observed: a buoyant surface jet and a negatively buoyant jet. The buoyant flow is parameterized with an initial densimetric Froude number, and agreement is good between the observed vertical penetration of the jet and that predicted by several existing models. The negatively buoyant jet entrains several times its initial volume; entrainment constants for the flow are larger than those observed from the two‐dimensional plume on similar inclines, yet smaller than those for neutrally buoyant jets. A time‐scale of 2 to 3 weeks is calculated for the flushing of the Inlet during times of negatively buoyant inflow. The buoyant jet is observed to reduce the overall density of the water column, and estimated vertical eddy diffusivities are considerably larger than in most other fjords. Changes in the Froude number of the jet are controlled primarily by changes in the density and speed of the inflow. During the period of observations the density of the jet appears to be controlled by runoff.     

Ergebnisse der luftelektrischen Arbeiten in Buchau a. F. Studien über das atmosphärische Potentialgefälle. VII

Zusammenfassung Aus 1 1/2jährigen Registrierungen des luftelektrischen Potentialgefälles und des Vertikalstromes wird ein Überblick über das Verhalten und den Verlauf dieser Elemente sowie der aus ihnen berechneten Leitfähigkeit an einer großstadtfernen Landstation der Hochebene von Südwürttemberg abgeleitet. Die Messungen wurden mit der in Buchau entwickelten Registrierapparatur zur gleichzeitigen Aufzeichnung von Potentialgefälle und Vertikalstrom an zwei Stellen des Dorfes Kappel ausgeführt, von denen die eine am N-Rand, die andere am SW-Rand des Dorfes lag. Die mittleren Tagesgänge der zwei Elemente und der daraus abgeleiteten Leitfähigkeit sind in den Wintermonaten charakterisiert durch geringe Leitfähigkeitsvariation und demgemäß fast parallelen Verlauf von Potentialgefälle und Vertikalstrom. Zum Sommer hin tritt, besonders bei Beschränkung auf ungestörte Tagesreihen, mit größer werdender Schwankungsamplitude der Leitfähigkeit in zunehmendem Maße antiparalleles Verhalten von Potentialgefälle und Strom in den Vordergrund. Unterschiede in den Ergebnissen der beiden Stationen sind zum Teil durch die örtlichen Verhältnisse, zum Teil durch die bei den beiden Elementen verschiedenartige Auswahl bedingt. An der Station Forsthaus Kappel wird durch Vergleich der Tagesgänge mit den für den gleichen Ort vor einigen Jahren aus Registrierungen mit dem Benndorf-Quadrantelektrometer abgeleiteten Gängen der Anschluß beider Meßmethoden aneinander hergestellt.

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Summary For 1 1/2 years the electric potential gradient and the air-earth current have been recorded at two places at the village of Buchau-Kappel on the tableland of southern Württemberg (Germany), far from cities. This was done by means of an apparatus developed in Buchau. One of these places was situated at the northern end, the other one at the southwest end of the village. In the following a summary is given of the behavior and the diurnal and annual variation of these two elements of atmospheric electricity. Furthermore the conductivity has been calculated from the two other elements.In the winter months the mean daily variation of the three elements is characterized by a small variation of conductivity and accordingly by an almost parallel course of potential gradient and air-earth current. During the summer months when the variations of conductivity are increasing, an antiparallel behavior of potential gradient and air-earth current prevails, especially if only undisturbed diurnal curves are taken into consideration. Differences of the results at the two stations are caused partly by local conditions, partly by a heterogeneous selection of the material.For one of these recording places a comparison of the daily variations according to the new records show a fairly good agreement with earlier records by a Benndorf electrometer.

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Résumé Des enregistrements simultanés du gradient de potentiel atmosphérique et du courant vertical ont été faits pendant un an et demi dans une station de campagne éloignée de la ville, sur le plateau du Wurtemberg méridional. Les mesures furent faites au moyen de l'appareillage, développé à Buchau, en deux endroits du village de Kappel, l'un au Nord et l'autre au Sud-Ouest de la localité. Les marches diurnes moyennes des deux éléments, ainsi que de la conductibilité qu'on en peut déduire, sont caractérisées en hiver par la faible variation de conductibilité et par conséquent par le parallélisme des courbes du gradient et du courant vertical. Vers l'été, et surtout en se limitant aux séries non perturbées, la variation de la conductibilité augmente d'amplitude et les courbes du gradient de potentiel et du courant vertical tendent à varier en sens contraire. Des divergences entre les deux stations sont dues en partie aux conditions locales et en partie au choix différent parmi les deux éléments. A la station «Forsthaus Kappel», une comparaison des variations diurnes des mesures en question et de celles effectuées précédemment au même endroit par des enregistrements avec l'électromètre Benndorf permet d'harmoniser les deux méthodes de mesure.

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Mit 6 Textabbildungen.     

Comment on “Trends and low frequency variability of extra-tropical cyclone activity in the ensemble of twentieth century reanalysis” by Xiaolan L. Wang,Y. Feng,G. P. Compo,V. R. Swail,F. W. Zwiers,R. J. Allan,and P. D. Sardeshmukh,Climate Dynamics, 2012

The main subject of this article is to comment on the issue of storminess trends derived from the twentieth century reanalysis (20CR) and from observations in the North Atlantic region written about in Wang et al. (Clim Dyn 40(11–12):2775–2800, 2012). The statement that the 20CR estimates would be consistent with storminess derived from pressure-based proxies does not hold for the time prior to 1950.     

A “precariously unprepared” Pentagon? Climate security beliefs and decision-making in the U.S. military

Increasing evidence suggests that climate change poses direct and indirect threats to national and human security. However, the degree to which such knowledge of the risks informs decision-making remains poorly understood for key security communities, including the U.S. Department of Defense. Here, through document analysis and interviews with climate security researchers and practitioners from the U.S. military community, we evaluate perceptions about and the degree to which (i) these individuals believe climate change is a threat to U.S. national security interests, and (ii) the U.S. Department of Defense integrates climate security science into its decision-making. Our research suggests a complex answer. Public statements and reports indicate U.S. Department of Defense leadership considers climate change a security threat of strategic importance, and most researchers interviewed believe the U.S. Department of Defense prioritizes climate security as a near-term threat. However, evidence of climate security threats is only selectively integrated into planning and decision-making. Interviews suggest several barriers and enablers to evidence-based decision-making within the U.S. Department of Defense. Barriers include mixed beliefs in the near-term urgency of the threat, changing political environments, and insufficient co-production of actionable science across the levels of war, including issues of data collection, sharing, and analysis. Enablers include increased awareness after climate-related impacts, strong leadership support, and knowledge transfer and convening forums. Improved insight into the production and use of climate security knowledge is crucial for the task of safeguarding human and national security in a changing climate.     

What (science for) adaptation to climate change in Colombian agriculture? A commentary on “A way forward on adaptation to climate change in Colombian agriculture: perspectives towards 2050” by J. Ramirez-Villegas, M. Salazar, A. Jarvis, C. E. Navarro-Valcines

Climate change is putting Colombian agriculture under significant stress and, if no adaptation is made, the latter will be severely impacted during the next decades. Ramirez-Villegas et al. (2012) set out a government-led, top-down, techno-scientific proposal for a way forward by which Colombian agriculture could adapt to climate change. However, this proposal largely overlooks the root causes of vulnerability of Colombian agriculture, and of smallholders in particular. I discuss some of the hidden assumptions underpinning this proposal and of the arguments employed by Ramirez-Villegas et al., based on existing literature on Colombian agriculture and the wider scientific debate on adaptation to climate change. While technical measures may play an important role in the adaptation of Colombian agriculture to climate change, I question whether these actions alone truly represent priority issues, especially for smallholders. I suggest that by i) looking at vulnerability before adaptation, ii) contextualising climate change as one of multiple exposures, and iii) truly putting smallholders at the centre of adaptation, i.e. to learn about and with them, different and perhaps more urgent priorities for action can be identified. Ultimately, I argue that what is at stake is not only a list of adaptation measures but, more importantly, the scientific approach from which priorities for action are identified. In this respect, I propose that transformative rather than technical fix adaptation represents a better approach for Colombian agriculture and smallholders in particular, in the face of climate change.     

Scavenging Efficiency of ‘Aerosol Carbon’ and Sulfate in Supercooled Clouds at Mt. Sonnblick (3106 m a.s.l., Austria)

Cloud water and interstitial aerosol samples collected at Mt. Sonnblick (SBO) were analyzed for sulfate and aerosol carbon to calculate in-cloud scavenging efficiencies. Scavenging efficiencies for sulfate (_SO) ranged from 0.52 to 0.99 with an average of 0.80. Aerosol carbon was scavenged less efficiently with an average value (_AC) of 0.45 and minimum and maximum values of 0.14 and 0.81, respectively. Both _SO and _AC showed a marked, but slightly different, dependence on the liquid water content (LWC) of the cloud. At low LWC, _SO increased with rising LWC until it reached a relatively constant value of 0.83 above an LWC of 0.3 g/m³. In the case of aerosol carbon, we obtained a more gradual increase of _AC up to an LWC of 0.5 g/m³. At higher LWCs, _{_} remained relatively constant at 0.60. As the differences between _SO and _A varied across the LWC range observed at SBO, we assume that part of the aerosol carbon was incorporated into the cloud droplets independently from sulfate. This hypothesis is supported by size classified aerosol measurements. The differences in the size distributions of sulfate and total carbon point to a partially external mixture. Thus, the different chemical nature and the differences in the size and mixing state of the aerosol particles are the most likely candidates for the differences in the scavenging behavior.     

Is Strange Weather in the Air? A Study of U.S. National Network News Coverage of Extreme Weather Events

This paper asks whether extreme weather events are becoming more discernible. It uses the Vanderbilt University Television News Archives to determine if annual coverage given to heat waves, droughts, hurricanes and floods has increased on the network news between 1968 and 1996. An index of extreme weather events shows a clear trend toward increased coverage, especially since 1988. However, the different types of extreme events do not receive equal coverage: for example, annual peaks for droughts contain about twice as many stories as the peaks for heat waves. The data further reveal that there is no association between coverage of climate change and the overall coverage of extreme events. While extreme events have attracted more stories in the U.S., there has been no increase in the coverage devoted to extreme events in foreign countries. The possible effects of shifts in TV coverage on the public salience and understanding of climate change are discussed.     

Physikalisch-chemische Verhältnisse in der Nord-Adria längs des 45. Breitenkreises

Zusammenfassung Die physikalischen und chemischen Verhältnisse der Gewässer der oberen Adria wurden während einer Frühlings- und einer Sommerperiode längs des 45. Breitenkreises beobachtet. Die Gleichzeitigkeit der Messungen wurde mit Hilfe dreier funkkommandierter Schiffe erreicht. Dabei zeigten sich folgende Unterschiede der Umwelteinflüsse: Die Gewässer der östlichen und der mittleren Zone gleichen dem reinen Meerwasser aus dem Süden, während die der westlichen Zone von den Zuflüssen der Flüsse beeinflußt sind.

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Summary An investigation of the physico-chemical conditions of the waters of the upper Adriatic has been carried out during a spring and a summer period along the 45th parallel. Due to the measurements being taken by three radio-commanded ships it was possible to effect them at exactly the same time. Water-conditions differ according to location: In the eastern and central zone the water corresponds to the pure sea-water coming from the south, while in the western zone the water is influenced by fluvial affluents.

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Résumé Les conditions physiques et chimiques des eaux de la Haute-Adriatique ont été observées pendant une période de printemps et une période d'été, le long d'une section à la hauteur du 45ème parallèle; la simultanéité des recherches était assurée, car les mesures furent effectuées par trois navires radiocommandés. Les états du milieu des eaux sont différents: celles des zones orientale et centrale correspondent aux eaux marines pures venant du sud tandis que dans la zone occidentale elles sont influencées par des affluents fluviaux.

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Riassunto Le condizioni fisico-chimiche delle acque dell'Alto Adriatico sono state osservate in un periodo primaverile ed in uno estivo lungo una sezione al 45° parallelo; la contemporaneità delle misure è stata assicurata a mezzo di misure effettuate con tre navi radiocomandate. Le condizioni ambientali delle acque sono diverse: quelle della zona orientale e centrale corrispondono alle acque marine pure provenienti dal sud, mentre nella zona occidentale le acque sono influenzate dal deflusso fluviale.

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Mit 4 Textabbildungen.     

Reply to comment by Ben-Zvi,A., D. Rosenfeld and A. Givati on the paper: Levin,Z., N. Halfon and P. Alpert, “Reassessment of rain experiments and operations in Israel including synoptic considerations,” Atmos. Res. 97, 513–525. DOI: 10.1016/j.atmosres.2010.06.011

Levin et al. (2010; hereafter LHA) (Levin, Z., Halfon, N., Alpert, P., 2010. Reassessment of rain experiments and operations in Israel including synoptic considerations. Atmos. Res. 97, 513–525. DOI:10.1016/j.atmosres.2010.06.011.), reanalyzed the results of the operational seeding in northern Israel between 1975 and 2007 and the preceding Israel 2 cloud seeding experiment (1969–1975) and concluded that there is no net increase in precipitation over the target areas. Our analysis revealed that a synoptic bias during Israel 2 is one of the reasons for the apparent positive effect of seeding in the northern target area and the negative effect in the southern area both of which disappeared in the following experiment in the south (Israel 3; 1975–1995) and the operational seeding in the north.Ben-Zvi et al. (2010;hereafter BRG) criticized our paper primarily on the ground that we did not consider the positive results of Israel 1 experiment (1960–1967). It should be noted that in Israel 1 different seeding lines were used from those in both Israel 2 and the operational period. In addition, its raw data is not accessible anymore for reanalysis. Furthermore, Israel 2 had been designed as a confirmatory cross-over experiment to Israel 1 and failed to reproduce its promising results with double ratio (DR) of ~ 1.00, namely, zero rainfall enhancements. The same DR values were also found in Israel 3 and in the operational seeding. Therefore, because of the differences in the two experiments, the lack of access to the raw data and the disappointing results of the confirmatory experiment, we decided to concentrate our analysis on the more recent seeding activities.The attempt by BRG to explain the reduction of the DR to ~ 1.00 in the operational seeding period by the suppression due to pollution have been disproved by Alpert et al., 2008, Alpert et al., 2009 and also fail to explain the sharp decline of the target/control ratio right at the beginning of the operational seeding period when the lucky draw in this area came to its end (see LHA).     

Tree-ring reconstruction of summer temperature for A.D. 1475–2003 in the central Hengduan Mountains, Northwestern Yunnan, China

Development of long tree-ring records is an important task in paleoclimate studies. Here we presented a five-century long reconstruction of summer (June to August) temperature based on a tree ring-width chronology of Picea brachytyla var. complanata originating from the Hengduan Mountains of China. Climate-growth response analysis showed that summer temperature was the main climatic factor limiting tree-ring growth in the study area. The reconstructed summer temperature accounted for 47.6% of the variance in actual temperature during their common period A.D. 1958–2002. Analysis of the temperature reconstruction showed that major warm periods occurred in the A.D. 1710s–1750s, 1850s, 1920s–1950s and 1990s to present, whereas cold intervals occurred in the A.D. 1630s–1680s, 1790s–1800s, 1860s–1880s and 1950s–1980s, respectively. The low-frequency variation of the reconstruction agreed fairly well with tree-ring reconstructed temperature from nearby regions and with records of glacier fluctuations in the surrounding high mountains, suggesting that our reconstructed summer temperature was reliable, and could aid in the evaluation of regional climate variability.     

Comments on “a Practical Method for Relating Scalar Concentrations to Source Distributions in Vegetation Canopies” by M. R. Raupach

This paper considers a modification to the localized near-field (LNF) theory for predicting scalar concentrations from source distributions in plant canopies. It is argued that the non-diffusive, near-field part of the transition probability P_n, and thus the near-field contribution of the scalar concentration C_n, in the original theory are simply errors. The (approximate) equality of the sum of C_n and the diffusive, far-field contribution C_f with the total scalar concentration C is not guaranteed in general by this theory. A revision is suggested.     

(九)A.I.D.的作图法

本讲介绍如何在图上进行A.I.D.的分类筛选预报,它的优点是避免了计算,利用和天气预报中常用的点聚图方法相类似的画法,就可以作出预报。现用一个实例来说明。 考虑长江中下游汉口、九江、芜湖、南京、上海五站平均5—8月降水总量(y),选用了1952—1976年25年资料用五个气象要素作为因子。 因子:x_1是一月0—150°E,45—65°N的纬向指数I_z, x_2是一月份欧洲大型环流型C型天数, x_3是一月份长江流域六站降水量∑R_1月, x_4是一月份长江流域六站温度∑月,