End-use Energy Model for Analyzing the Policy Options to Reduce Greenhouse Gas Emissions

The objective of this work is to develop the end-use energy model for assessing the policy options to reduce greenhouse gas emissions. This model is a part of the integrated model called AIM (the Asian-Pacific Integrated Model). This module evaluates the effect of introducing a carbon tax on various carbon emission countermeasure technologies such as energy conservation technologies, and the size of consequent CO2 emission reductions. It also estimates the increased effect when the carbon tax is combined with other countermeasure policies, such as the introduction of subsidies. This model was applied to the Japanese case. The conditions for which each energy conservation technology menu would be adopted were defined using its relationship with the carbon tax rate and subsidy assuming a certain end-use energy scenario. Then, the relationships between the introduction of these technology menus and reduced CO2 emissions based on various socioeconomic scenarios were analyzed and an evaluation was made of the effects of combining a carbon tax and subsidies using the recycled revenues from such a tax

Implications of Japan’s long term climate mitigation target and the relevance of uncertain nuclear policy

Achieving long-term climate mitigation goals in Japan faces several challenges, starting with the uncertain nuclear power policy after the 2011 earthquake, the uncertain availability and progress of energy technologies, as well as energy security concerns in light of a high dependency on fuel imports. The combined weight of these challenges needs to be clarified in terms of the energy system and macroeconomic impacts. We applied a general equilibrium energy economic model to assess these impacts on an 80% emission reduction target by 2050 considering several alternative scenarios for nuclear power deployment, technology availability, end use energy efficiency, and the price of fossil fuels. We found that achieving the mitigation target was feasible for all scenarios, with considerable reductions in total energy consumption (39%–50%), higher shares of low-carbon sources (43%–72% compared to 15%), and larger shares of electricity in the final energy supply (51%–58% compared to 42%). The economic impacts of limiting nuclear power by 2050 (3.5% GDP loss) were small compared to the lack of carbon capture and storage (CCS) (6.4% GDP loss). Mitigation scenarios led to an improvement in energy security indicators (trade dependency and diversity of primary energy sources) even in the absence of nuclear power. Moreover, preliminary analysis indicates that expanding the range of renewable energy resources can lower the macroeconomic impacts of the long term target considerably, and thus further in depth analysis is needed on this aspect. Key policy insights For Japan, an emissions reduction target of 80% by 2050 is feasible without nuclear power or CCS. The macroeconomic impact of such a 2050 target was largest without CCS, and smallest without nuclear power. Energy security indicators improved in mitigation scenarios compared to the baseline

What do near-term observations tell us about long-term developments in greenhouse gas emissions? A letter

Long-term scenarios developed by integrated assessment models are used in climate research to provide an indication of plausible long-term emissions of greenhouse gases and other radiatively active substances based on developments in the global energy system, land-use and the emissions associated with these systems The phenomena that determine these long-term developments (several decades or even centuries) are very different than those that operate on a shorter time-scales (a few years) Nevertheless, in the literature, we still often find direct comparisons between short-term observations and long-term developments that do not take into account the differing dynamics over these time scales In this letter, we discuss some of the differences between the factors that operate in the short term and those that operate in the long term We use long-term historical emissions trends to show that short-term observations are very poor indicators of long-term future emissions developments Based on this, we conclude that the performance of long-term scenarios should be evaluated against the appropriate, corresponding long-term variables and trends The research community may facilitate this by developing appropriate data sets and protocols that can be used to test the performance of long-term scenarios and the models that produce the

Assessment of the Al–Fe–Ti system

The Al–Fe–Ti system has been assessed and the limiting binary systems are shortly reviewed. Based on a thorough review of the literature, isotherms at 800, 900, and 1000 °C have been re-evaluated and a provisional isotherm at 1200 °C is presented for the first time. The effect of alloying the binary phases with the third component is reviewed with regard to the ternary homogeneity ranges, crystallography, order/disorder transformations, and site occupancies. Of the variously reported ternary compounds only the existence of “Al2FeTi” (τ2) and “Al8FeTi3” (τ3) is confirmed. The occurrence of the phases τ2*, τ′2, and of a new stacking variant of TiAl is still under discussion, while the existence of the phases Fe2AlTi (τ1) and Fe25Al69Ti6 (X) is ruled out. The presented reaction scheme corroborates the isothermal sections and also a representation of the liquidus surface is given. Magnetic, electrical, thermochemical, atomistic and diffusion data for Al–Fe–Ti alloys are summarised and an overview about studies on modelling of phase equilibria and phase transformations is given

Geometrical Magnetic Frustration in Rare Earth Chalcogenide Spinels

We have characterized the magnetic and structural properties of the CdLn2Se4 (Ln = Dy, Ho), and CdLn2S4 (Ln = Ho, Er, Tm, Yb) spinels. We observe all compounds to be normal spinels, possessing a geometrically frustrated sublattice of lanthanide atoms with no observable structural disorder. Fits to the high temperature magnetic susceptibilities indicate these materials to have effective antiferromagnetic interactions, with Curie-Weiss temperatures theta ~ -10 K, except CdYb2S4 for which theta ~ -40 K. The absence of magnetic long range order or glassiness above T = 1.8 K strongly suggests that these materials are a new venue in which to study the effects of strong geometrical frustration, potentially as rich in new physical phenomena as that of the pyrochlore oxides.Comment: 17 pages, 5 figures, submitted to Phys Rev B; added acknowledgement

Magnetic phase separation in ordered alloys

We present a lattice model to study the equilibrium phase diagram of ordered alloys with one magnetic component that exhibits a low temperature phase separation between paramagnetic and ferromagnetic phases. The model is constructed from the experimental facts observed in Cu$_{3-x}$AlMn$_{x}$ and it includes coupling between configurational and magnetic degrees of freedom which are appropriated for reproducing the low temperature miscibility gap. The essential ingredient for the occurrence of such a coexistence region is the development of ferromagnetic order induced by the long-range atomic order of the magnetic component. A comparative study of both mean-field and Monte Carlo solutions is presented. Moreover, the model may enable the study of the structure of the ferromagnetic domains embedded in the non-magnetic matrix. This is relevant in relation to phenomena such as magnetoresistance and paramagnetism.Comment: 12 pages, 11 figures, accepted in Phys. Rev.