International and national climate policies for aviation: a review

Aviation constitutes about 2.5% of all energy-related CO₂ emissions and in addition there are non-CO₂ effects. In 2016, the ICAO decided to implement a Carbon Offsetting and Reduction Scheme for International Aviation (CORSIA) and in 2017 the EU decided on faster emission reductions in its Emissions Trading System (EU ETS), which since 2012 includes the aviation sector. The effects of these policies on the expected development of air travel emissions from 2017 to 2030 have been analyzed. For the sample country Sweden, the analysis shows that when emissions reductions in other sectors are attributed to the aviation sector as a result of the EU ETS and CORSIA, carbon emissions are expected to reduce by ?0.8% per year (however if non-CO₂ emissions are included in the analysis, then emissions will increase). This is much less than what is needed to achieve the 2°C target. Our analysis of potential national aviation policy instruments shows that there are legally feasible options that could mitigate emissions in addition to the EU ETS and CORSIA. Distance-based air passenger taxes are common among EU Member States and through increased ticket prices these taxes can reduce demand for air travel and thus reduce emissions. Tax on jet fuel is an option for domestic aviation and for international aviation if bilateral agreements are concluded. A quota obligation for biofuels is a third option.

Key policy insights

• Existing international climate policies for aviation will not deliver any major emission reductions.

• Policymakers who want to significantly push the aviation sector to contribute to meeting the 2°C target need to work towards putting in place tougher international policy instruments in the long term, and simultaneously implement temporary national policy instruments in the near-term.

• Distance-based air passenger taxes, carbon taxes on jet fuel and quota obligations for biofuels are available national policy options; if they are gradually increased, and harmonized with other countries, they can help to significantly reduce emissions.

     

沿阿穆尔板块西边界的活动断层(蒙古领土)

阿穆尔板块西部边界在蒙古境内的空间位置尚不清楚,并且活动断层构造及其沿线地壳的应力状态研究较少。本文在沿此边界的三个区域——杭爱—肯特构造鞍部、布尔古特地块(鄂尔浑—土拉交汇处)和色楞格地块(包括色楞格凹陷和布伦—努鲁隆起),利用空间图像解译、地形起伏度分析、地质构造资料以及构造压裂和沿裂缝位移资料重建构造古应力,对活动断层进行研究。研究表明,活动断裂继承了古生代和中生代古构造的非均质性。这些断层沿着板块边界并不是单一的带,而是成簇的。它们的运动取决于走向:亚纬向断层是具有一定逆分量的左旋走滑断层,北西向断层是逆断层或逆冲断层,通常具有右旋走滑分量,海底断层是右旋走滑断层,北东向断层是正断层。位于色楞格凹陷和杭爱东部的断裂构造的活动始于上新世。逆断层和走滑断层与上新世情况不符,但多与更新世地貌相符,表明其活动年代较晚,为更新世时期。利用构造断裂和沿断裂的位移,重建活动断裂带变形末阶段的应力应变状态,结果表明断裂在最大挤压轴的北北东和北东方向上以压缩和走滑为主。只有在色楞格凹陷内,以扩张和走滑类型的应力张量为主,且在最小挤压轴的北西走向尤为显著。在南部,杭爱东部(鄂尔浑地堑)内有1个以扩张机制为主的局部区域,说明蒙古中部断裂在更新世—全新世阶段的活动以及现代地震活动主要受与印度斯坦和欧亚大陆汇聚过程相关的东北方向的附加水平挤压的控制。使研究区地壳产生走滑变形、贝加尔湖裂谷发散活动以及阿穆尔板块东南运动的另一个因素是东南方向软流圈流动对岩石圈底部的影响。阿穆尔板块和蒙古地块之间的边界在构造结构上是零碎的,代表了覆盖整个蒙古西部变形带的边缘部分。     

A review of the impacts of pumped hydro energy storage construction on subalpine and alpine biodiversity: lessons for the Snowy Mountains pumped hydro expansion project

ABSTRACT

The Australian government’s proposal to expand the Snowy Hydro Scheme to include a second pumped hydro energy storage (PHES) system, and support for feasibility studies for PHES in Tasmania, offer an opportunity to incorporate more intermittent renewable energy generation into the National Energy Market. However, the infrastructure construction required for PHES expansion may have negative effects for biodiversity in subalpine and alpine areas. To identify the potential effects of PHES on biodiversity in Kosciuszko National Park (KNP), this systematic literature review assesses: (i) the key environmental disturbances likely to arise from PHES construction; and (ii) the specific impacts of these construction processes on biodiversity in subalpine and alpine environments. We find that the effects of PHES construction-related disturbances are likely to be negative for subalpine and alpine biodiversity, with impacts including the proliferation of exotic flora, habitat loss resulting from vegetation clearing, altered landscape hydrology and reduced water quality. Management recommendations to limit these impacts are provided and further research is recommended to assess: (i) the effects of PHES on fish populations in alpine reservoirs; (ii) the utility of spoil as artificial habitat for endemic fauna; and (iii) the chemical and physical impacts of spoil dumping in alpine reservoirs.     

Flood-type trend analysis for alpine catchments

ABSTRACT

In many places, magnitudes and frequencies of floods are expected to increase due to climate change. To understand these changes better, trend analyses of historical data are helpful. However, traditional trend analyses do not address issues related to shifts in the relative contributions of rainfall versus snowmelt floods, or in the frequency of a particular flood type. We present a novel approach for quantifying such trends in time series of floods using a fuzzy decision tree for event classification and applied it to maximal annual and seasonal floods in 27 alpine catchments for the period 1980–2014. Trends in flood types were studied with Sen’s slope and double mass curves. Our results reveal a decreasing number of rain-on-snow and an increasing number of short rainfall events in all catchments, with flash floods increasing in smaller catchments. Overall, the results demonstrate the value of incorporating a fuzzy flood-type classification into flood trend analyses.     

Atmospheric electricity measurements over the Indian Ocean

Summary Results of measurements of the atmospheric electrical conductivity and potential gradient made during the sixth Scientific Cruise of the Indian Oceanographic Ship INS Kistna in the Bay of Bengal during February–March 1963 are presented. Observations were made when the skies were generally clear and the sea calm, in the geographical area 8°N to 17°N and 80°E to 95°E, on the outward journey of INS Kistna from Madras (80°E, 13°N) to Port Blair (93°E, 12°N) and on the return journey to Madras.Over the ocean where there are no local sources of pollution, the measured values of conductivity and potential gradient are in agreement with theoretical values, assuming that an ion equilibrium exists, that ions are destroyed primarily by collision with small ions of opposite sign and that small ions are produced only by cosmic radiation. The values of electrical conductivity obtained are generally of the same order as those to be expected from theoretical considerations and in general agreement with those obtained during the Carnegie cruises in the Indian Ocean in 1920. There are, however, significant variations near the coast where the electric structure above the ocean is affected by continental sources of pollution. Conductivity values near the land are about half that in the unpolluted air over the ocean but prevailing winds prevent the extension of pollution beyond 100–200 km from the coast in this season.

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Zusammenfassung Es wird über Messungen der luftelektrischen Leitfähigkeit und des Potentialgefälles berichtet, welche während der Sechsten Wissenschaftlichen Kreuzfahrt des indischen Ozeanographischen Forschungsschiffes Ins Kistna in der Bengalischen Bucht im Februar und März 1963 ausgeführt wurden. Die Beobachtungen sind im allgemeinen bei klarem Himmel und ruhiger See gemacht worden, und zwar in dem geographischen Bereich zwischen 8 und 17°N und 80 und 95°E während der Ausfahrt der INS Kistna von Madras (80°E, 13°N) nach Port Blair (93°E, 12°N) und auf der Rückreise nach Madras. In den Bereichen des Ozeans, in denen keine örtlichen Pollutionsquellen bestehen, stimmen die gemessenen Werte der Leitfähigkeit und des Potentialgefälles mit den theoretischen Werten überein, die man erhält, wenn man annimmt, dass ein Ionengleichgewicht besteht, dass die schnellen Ionen vorwiegend durch Zusammenstoss mit schnellen Ionen des entgegengesetzten Vorzeichens vernichtet werden, und dass die schnellen Ionen nur durch die kosmische Höhenstrahlung erzeugt werden. Die Werte der Leitfähigkeit stimmen mit denen überein, die man aus theoretischen Überlegungen gewinnt, und auch mit denen, die während der Kreuzfahrten des Forschungsschiffes Carnegie im Indischen Ozean im Jahre 1920 gemessen Küste sind jedoch bedeutsame Abweichungen festzustellen, wo die elektrischen Verhältenisse über dem Ozean durch Pollutionsquellen auf dem Lande beeinflusst werden. Die Leitfähigkeitswerte nahe dem Land sind nur ungefähr halb so gross wie die in der pollutionsfreien Luft des offenen Ozeans-jedoch haben die während der Mess-Jahreszeit vorherrschenden Winde eine Ausbreitung der Pollutionszone auf einen Bereich von 100 bis 200 km von der Küste beschränkt.

     

The sources and budget for dissolved sulfate in a fractured carbonate aquifer,southern Sacramento Mountains,New Mexico,USA

Climate change in the SW USA is likely to involve drier conditions and higher surface temperatures. In order to better understand the evolution of water chemistry and the sources of aqueous SO₄ in these semi-arid settings, chemical and S isotope compositions were determined of springs, groundwater, and bedrock associated with a Permian fractured carbonate aquifer located in the southern Sacramento Mountains, New Mexico, USA. The results suggest that the evolution of water chemistry in the semi-arid carbonate aquifer is mainly controlled by dedolomitization of bedrock, which was magnified by increasing temperature and increasing dissolution of gypsum/anhydrite along the groundwater flow path. The δ³⁴S of dissolved SO₄ in spring and groundwater samples varied from +9.0‰ to +12.8‰, reflecting the mixing of SO₄ from the dissolution of Permian gypsum/anhydrite (+12.3‰ to +13.4‰) and oxidation of sulfide minerals (−24.5‰ to −4.2‰). According to S isotope mass balance constraints, the contribution of sulfide-derived SO₄ was considerable in the High Mountain recharge areas, accounting for up to ∼10% of the total SO₄ load. However, sulfide weathering decreased in importance in the lower reaches of the watershed. A smaller SO₄ input of ∼2–4% was contributed by atmospheric wet deposition. This study implies that the δ³⁴S variation of SO₄ in semi-arid environments can be complex, but that S isotopes can be used to distinguish among the different sources of weathering. Here it was found that H₂SO₄ dissolution due to sulfide oxidation contributes up to 5% of the total carbonate weathering budget, while most of the SO₄ is released from bedrock sources during dedolomitization.     

Spectral data source effect on crop state estimation by vegetation indices

Spectral vegetation indices (VIs) are a well-known and widely used method for crop state estimation. The ability to monitor crop state by such indices is an important tool for agricultural management. Even though differences in imagery and point-based spectroscopy are obvious, their impact on crop state estimation by VIs is not well-studied. The aim of this study was to assess the performance level of the selected VIs calculated from spaceborne multispectral imagery and point-based field spectroscopy in application to crop state estimation. For this purpose, irrigated chickpea field was monitored by RapidEye satellite mission and additional measurements by field spectrometer were obtained. Estimated VIs average and coefficient of variation from each observation were compared with physical crop measurements: leaf water content, LAI and chlorophyll level. The results indicate that indices calculated from spaceborne spectral images regardless of the claimed response commonly react on phenology of the irrigated chickpea. This feature makes spaceborne spectral imagery an appropriate data source for monitoring crop development, crop water needs and yield prediction. VIs calculated from field spectrometer were sensitive for estimating pigment concentration and photosynthesis rate. Yet, a hypersensitivity of field spectral measures might lead to a very high variability (up to 69%) of the calculated values. Consequently, the high spatial variability of field spectral measurements depreciates the estimation agricultural field state by average mean only. Nevertheless, the spatial variability might have certain behavior trend, e.g., a significant increase in the active growth or stress and can be an independent feature for field state assessment.     

Resonant structure of the outer asteroid belt

An analysis of ordered and chaotic regions of motion in the outer asteroid belt has shown that once the eccentricity of Jupiter is introduced the chaotic regions of the circular model are quite easily depleted. This suggests that also objects in neighbouring regions must be strongly perturbed. Therefore it is not surprising that many outer belt asteroids have been reported in the literature as resonant or anyway dynamically protected. By using the planar elliptic restricted 3-body model we have investigated the motion of outer belt asteroids which had not been suspected to librate. We find 3 cases of libration and 11 cases of e, coupling that can be explained within the theory of secular resonances. It is thus established that in the outer belt only resonant and dynamically protected asteroids can have lifetimes of the same order as the age of the Solar System.     

High-Nb hawaiite–mugearite and high-Mg calc-alkaline lavas from northeastern Iran: Oligo-Miocene melts from modified mantle wedge

Tertiary volcanic rocks in northwestern Firoozeh, Iran (the Meshkan triangular structural unit), constitute vast outcrops (up to 250 km²) of high-Mg basaltic andesites to dacites that are associated with high-Nb hawaiites and mugearites. Whole-rock ⁴⁰Ar/³⁹Ar ages show a restricted range of 24.1 ± 0.4–22.9 ± 0.5 Ma for the volcanic rocks. The initial ratios of ⁸⁷Sr/⁸⁶Sr and ¹⁴³Nd/¹⁴⁴Nd vary from 0.703800 to 0.704256 and 0.512681 to 0.512877, respectively, in the high-Mg basaltic andesites–dacites. High-Th contents (up to 11 ppm) and Sr/Y values (27–100) and the isotopic composition of the subalkaline high-Mg basaltic andesites–dacites indicate derivation from a mantle modified by slab and sediment partial melts. Evidence such as reverse zoning and resorbed textures and high Ni and Cr contents in the evolved samples indicate that magma mixing with mafic melts and concurrent fractional crystallization lead to the compositional evolution of this series. The high-Nb hawaiites and mugearites, by contrast, have a sodic alkaline affinity and are silica undersaturated; they are also enriched in Nb (up to 47 ppm) and a wide range of incompatible trace elements, including LILE, LREE, and HFSE. Geochemistry and Sr–Nd isotopic compositions of the high-Nb hawaiites and mugearites suggest derivation from a mantle source affected by lower degrees of slab melts. Post-orogenic slab break-off is suggested to have prompted the asthenospheric upwelling that triggered partial melting in mantle metasomatized by slab-derived melts.