the implications of phasing out free allowances

The allocation of free allowances for firms belonging to the carbon leakage list of the European Union Emissions Trading Scheme (EU ETS) was found to lead to substantial overcompensation, which is why some stakeholders recently have called for a phasing out of free allowances in the near term. This paper analyzes the consequences of phasing out free allowances in a dynamic two- period model when one group of countries unilaterally implements climate policies such as an emissions trading scheme. A carbon price induces firms to invest in abatement capital, but may also lead to the relocation of some firms. The social planner addresses the relocation problem by offering firms transfers, i.e. free allowances, conditional on maintaining the production in the regulating country. If transfers are unrestricted in both periods, then the social planner can implement the first best by setting the carbon price equal to the marginal environmental damage and using transfers to prevent any relocation. However, if transfers in the future period are restricted, it is optimal to implement a declining carbon price path with the first period price exceeding the marginal environmental damage. A high carbon price triggers investments in abatement capital and thus creates a lock-in effect. With a larger abatement capital stock, firms are less affected by carbon prices in the future and therefore less prone to relocate in the second period where transfers are restricted

Prices versus Quantities: The Impact of Fracking on the Choice of Climate Policy Instruments in the Presence of OPEC

This paper analyzes the impact of declining extraction costs of shale oil producers on the choice of the policy instrument of a climate coalition in the presence of a monopolistic oil supplier such as OPEC. Shale oil producers' extraction costs represent an upper bound for the oil price OPEC can charge. Declining extraction costs ultimately limit OPEC's price setting behavior and thus impacts the optimal climate policy of the climate coalition. A pure cap- and-trade system is weakly welfare-inferior relative to a carbon tax for the climate coalition. While high extraction costs allow OPEC to appropriate the whole climate rent in case of quantity regulation, declining extraction costs imply OPEC to capture only a part of the climate rent. A carbon tax always generates positive revenue and thus is welfare-superior in general. However, low extraction costs prevent OPEC from exerting its market power, leading the climate coalition to implement the Pigouvian tax in the first place. Both market-based instruments are equivalent in this case. Complementing a quota with a base tax cannot outperform a pure carbon tax

The Green Paradox and Learning-by-Doing in the Renewable Energy Sector

The green paradox conveys the idea that climate policies may have unintended side effects when taking into account the reaction of fossil fuel suppliers. In particular, carbon taxes that will be implemented in the future induce resource owners to extract more rapidly which increases present carbon dioxide emissions and accelerates global warming. Our results suggest that future carbon taxes may even decrease present emissions if resource owners face increasing marginal extraction costs and if there is a clean energy source that is a perfect substitute and exhibits learning-by-doing (LBD). If the marginal extraction cost curve is sufficiently at, resource owners respond to a future carbon tax with lowering total extraction and only slightly increase present extraction. Moreover, taxation leads to higher energy prices which induces the renewable energy firms to increase output not only in the future, but also in the present because of the anticipated benefits from LBD. This crowds out energy from the combustion of fossil fuels and may outweigh the initial increase in present extraction, leading to less emissions in the present

The Green Paradox and Learning-by-doing in the Renewable Energy Sector

21 p.We investigate the effect of climate policies on fossil fuel use in the presence of a clean alternative technology that exhibits learning-by-doing. In a two-period framework, the costs of clean and regenerative energy in the second period are decreasing with the amount of this energy produced in the first one. While a carbon tax on present fossil fuels always reduces the use of the conventional energy source, the effect of a subsidy for regenerative energy is ambiguous and depends on the size of the learning effect. For small learning effects, a subsidy reduces the present use of fossil fuels since their substitute becomes comparatively cheap. However, for larger learning effects, a subsidy leads to the green paradox as the cost reduction in the clean energy sector reduces the future demand for conventional energy and brings forward extraction. We conclude that the best way to reduce present CO2 emissions is the implementation of a carbon tax. If the learning effect is small, the carbon-tax revenues should additionally finance the subsidy for the renewable energy

Do environmental and economic performance go together? A review of micro-level empirical evidence from the past decade or so

This article reviews the empirical literature combining economic and environmental performance data at the micro-level, i.e. firm or facility level. The literature has generally found a positive and statistically significant correlation between economic performance, as measured by profitability indicators or stock market returns, and environmental performance, as measured by emissions of pollutants or adoption of international environmental standards. The main reason for this finding seems to be that firms that reduce their material and energy costs experience both better economic performance and lower emissions. Only a small and recent literature analyses the joint causal impact of environmental regulations on environmental and economic performance. Interestingly, this literature shows that environmental regulations tend to improve environmental performance while not weakening economic performance. However, the evidence so far is limited to a handful of environmental regulations that are not extremely stringent, so the result cannot be easily generalized. More research is needed to assess the joint effects of environmental regulations on environmental and economic performance, to explore the heterogeneity of these effects across sectors, countries and types of policies, and to understand which policy designs allow improving environmental quality while not coming at a cost in terms of economic performance of regulated businesses

The ground-based large-area wide-angle gamma-ray and cosmic-ray experiment HiSCORE

The question of the origin of cosmic rays and other questions of astroparticle and particle physics can be addressed with indirect air-shower observations above 10 TeV primary energy. We propose to explore the cosmic ray and gamma-ray sky (accelerator sky) in the energy range from 10 TeV to 1 EeV with the new ground-based large-area wide angle (~0.85 sterad) air-shower detector HiSCORE (Hundred*i Square-km Cosmic ORigin Explorer). The HiSCORE detector is based on non-imaging air-shower Cherenkov light-front sampling using an array of light-collecting stations. A full detector simulation and basic reconstruction algorithms have been used to assess the performance of HiSCORE. First prototype studies for different hardware components of the detector array have been carried out. The resulting sensitivity of HiSCORE to gamma-rays will be comparable to CTA at 50 TeV and will extend the sensitive energy range for gamma-rays up to the PeV regime. HiSCORE will also be sensitive to charged cosmic rays between 100 TeV and 1 EeV.Comment: Tluczykont, M., et al. The ground-based large-area wide-angle c-ray and cosmic-ray experiment HiSCORE., accepted, J. Adv. Space Res. (2011), 13 pages, 4 figure

Physicians' awareness of gadolinium retention and MRI timing practices in the longitudinal management of pituitary tumors::a "Pituitary Society" survey

PURPOSE: In view of mounting attention related to possible brain retention of gadolinium-based contrast agents (GBCAs) in patients with normal renal function, our purpose was to detail results from a survey of pituitary experts to assess: 1) the timing interval and frequency of pituitary magnetic resonance imaging (MRI) following surgical and/or medical and/or radiation therapy of pituitary tumors, 2) awareness of the types of GBCAs used and their possible safety issues. METHODS: The Pituitary Society Education Committee composed a survey with 12 multiple choice questions, 8 of which specifically addressed the time interval and frequency of MRI in the longitudinal management of pituitary tumors. The survey was distributed at two meetings; the International Pituitary Neurosurgeons Society conference in San Diego, CA, on February 18th, 2018, and the Pituitary Society Membership and Career Development Forum, Chicago, IL on March 18th, 2018. RESULTS: There is consensus among pituitary endocrinologists and neurosurgeons that long-term repeated imaging is recommended in most pituitary tumors, although the precise strategy of timing varied depending on the specialist group and the specific clinical context of the adenoma. The data also suggest that International Pituitary Neurosurgeons Society neurosurgeons, as well as Pituitary Society neuroendocrinologists, are sometimes unaware of which contrast agents are used by their institution, and many are also unaware that evidence of long-term brain retention has been reported with the use of GBCAs in patients with normal function. CONCLUSIONS: International pituitary endocrinologists and pituitary neurosurgeons experts suggest ongoing MRIs for the management of pituitary tumors; strategies vary based on clinical context, but also on individual experience and practice

The preparation route and final form of V-MXenes override the effect of the O/F ratio on their magnetic properties

This work was supported by OP VVV “Excellent Research Teams” project no. CZ.02.1.01/0.0/0.0/15_003/0000417 – CUCAM. P. E. would like to also acknowledge the Czech Science Foundation for the ExPro project (19-27551X). Computational resources and low-temperature infrastructure were supplied by the projects “e-Infrastruktura CZ” (e-INFRA CZ LM2018140) and MGML (LM2023065) supported by the Ministry of Education, Youth and Sports of the Czech Republic.Transition metal carbides and nitrides (MXenes) show a high potential for electrochemical energy storage in batteries and supercapacitors and for electrocatalysis. Their excellent electronic and magnetic characteristics have been highlighted in several theoretical studies. However, experimental research on MXenes is yet to confirm their predicted properties as candidates for controllable magnetic 2D materials. Here, we report our theoretical and experimental study of V2CTx MXenes (T = O, OH, F), providing key insights into their magnetism. Based on our density functional theory (DFT) analysis, we predicted ferromagnetic (FM) and antiferromagnetic (AFM) states of V2CTx, which are determined by the O/F ratio of surface functional groups. Accordingly, we prepared V2CTx MXenes in the form of multilayered powders and thin films with different O/F ratios. No experimental evidence of FM or AFM properties was found in any material. Nevertheless, powders and films with almost identical chemical compositions (in terms of O/F ratio) displayed different magnetic properties, whereas films with disparate chemical compositions revealed a similar magnetic character. Therefore, the preparation route and form of the final V2CTx material override the effect of the O/F ratio, which is often overestimated in theoretical studies. Moreover, these findings underscore the importance of preparing MXene materials to experimentally confirm their theoretically predicted properties.Peer reviewe

In Vivo Time- Resolved Microtomography Reveals the Mechanics of the Blowfly Flight Motor

Dipteran flies are amongst the smallest and most agile of flying animals. Their wings are driven indirectly by large power muscles, which cause cyclical deformations of the thorax that are amplified through the intricate wing hinge. Asymmetric flight manoeuvres are controlled by 13 pairs of steering muscles acting directly on the wing articulations. Collectively the steering muscles account for <3% of total flight muscle mass, raising the question of how they can modulate the vastly greater output of the power muscles during manoeuvres. Here we present the results of a synchrotron-based study performing micrometre-resolution, time-resolved microtomography on the 145 Hz wingbeat of blowflies. These data represent the first four-dimensional visualizations of an organism's internal movements on sub-millisecond and micrometre scales. This technique allows us to visualize and measure the three-dimensional movements of five of the largest steering muscles, and to place these in the context of the deforming thoracic mechanism that the muscles actuate. Our visualizations show that the steering muscles operate through a diverse range of nonlinear mechanisms, revealing several unexpected features that could not have been identified using any other technique. The tendons of some steering muscles buckle on every wingbeat to accommodate high amplitude movements of the wing hinge. Other steering muscles absorb kinetic energy from an oscillating control linkage, which rotates at low wingbeat amplitude but translates at high wingbeat amplitude. Kinetic energy is distributed differently in these two modes of oscillation, which may play a role in asymmetric power management during flight control. Structural flexibility is known to be important to the aerodynamic efficiency of insect wings, and to the function of their indirect power muscles. We show that it is integral also to the operation of the steering muscles, and so to the functional flexibility of the insect flight motor

Carbon pricing, health co-benefits and trade-offs: protocol for a systematic framework synthesis

Carbon pricing is considered an important instrument in the fight against climate change (World Bank, 2022). In particular, many experts and stakeholders have called for the implementation of carbon pricing as a part of ambitious climate policy agendas (Hepburn et al., 2020). This requires consideration of the interactions of carbon pricing with other policies, as well as of the societal outcomes of carbon pricing. In particular, carbon pricing has been found to have potentially large health impacts, leading to important co-benefits as well as potentially some trade-offs (Parry et al., 2014), (Hasegawa et al., 2018). Information on health impacts of carbon pricing, their distribution and how they are affected by policy design is necessary in order to progress towards more socially sustainable and politically feasible policy design. Recent reviews have focussed on various aspects of carbon pricing design and outcomes, synthesizing evidence on its effectiveness, equity impacts or societal perception (Boyce, 2018), (Green, 2021), (Maestre-Andrés et al., 2019). Others have reviewed the evidence on health co-benefits of mitigation, but do not analyse specific policies or issues of policy design Gao et al.(2018). This review will narratively synthesize the evidence on the health impacts of carbon pricing between 2010 and 2021 and identify gaps in the literature. We will use a framework synthesis approach to analyse different categories of policy-relevant information in contexts where carbon pricing is implemented as part of wider, coordinated policy agendas or complex policy mixes. This includes for example impacts on health inequalities and how health co-benefits are affected by issues of policy design and policy interactions.</ns4:p