Nucleosynthesis During Silicon Burning

Silicon burning at temperatures in the neighborhood of 4 × 109 °K has been studied with the aid of a quasiequilibrium model which describes the abundance of the nuclei in the interval 28\u3c~A\u3c~62. It is found that, for a broad range of temperatures and densities, silicon burning leads to nuclear abundance distributions which match important features of the natural solar-system abundance distributions and that a large nuclear energy release accompanies silicon burning

Climate justice and the international regime: before, during and after Paris

With a focus on key themes and debates, this article aims to illustrate and assess how the interaction between justice and politics has shaped the international regime and defined the nature of the international agreement that was signed in COP21 Paris. The work demonstrates that despite the rise of neo-conservatism and self-interested power politics, questions of global distributive justice remain a central aspect of the international politics of climate change. However, while it is relatively easy to demonstrate that international climate politics is not beyond the reach of moral contestations, the assessment of exactly how much impact justice has on climate policies and the broader normative structures of the climate governance regime remains a very difficult task. As the world digests the Paris Agreement, it is vital that the current state of justice issues within the international climate change regime is comprehensively understood by scholars of climate justice and by academics and practitioners, not least because how these intractable issues of justice are dealt with (or not) will be a crucial factor in determining the effectiveness of the emerging climate regime

Can Red Clay Go Green? Adapting Law and Policy in the Face of Climate Change, 20th Annual Red Clay Conference

Program for the 20th Annual Red Clay Conference held Friday, April 4, 2008 at the University of Georgia School of Law\u27s Dean Rusk Hall

The challenges of monitoring national climate policy: learning lessons from the EU

One of the most central and novel features of the new climate governance architecture emerging from the 2015 Paris Agreement is the transparency framework committing countries to provide, inter alia, regular progress reports on national pledges to address climate change. Many countries will rely on public policies to turn their pledges into action. This article focuses on the EU’s experience with monitoring national climate policies in order to understand the challenges that are likely to arise as the Paris Agreement is implemented around the world. To do so, the research employs – for the first time – comparative empirical data submitted by states to the EU’s monitoring system. Our findings reveal how the EU’s predominantly technical interpretation of four international reporting quality criteria – an approach borrowed from reporting on GHG fluxes – has constrained knowledge production and stymied debate on the performance of individual climate policies. Key obstacles to more in-depth reporting include not only political concerns over reporting burdens and costs, but also struggles over who determines the nature of climate policy monitoring, the perceived usefulness of reporting information, and the political control that policy knowledge inevitably generates. Given the post-Paris drive to achieve greater transparency, the EU’s experience offers a sobering reminder of the political and technical challenges associated with climate policy monitoring, challenges that are likely to bedevil the Paris Agreement for decades to come

Non-state actors in hybrid global climate governance: justice, legitimacy, and effectiveness in a post-Paris era

In this article, we outline the multifaceted roles played by non-state actors within the United Nations Framework Convention on Climate Change and place this within the wider landscape of global climate governance. In doing so, we look at both the formation and aftermath of the 2015 Paris Agreement. We argue that the Paris Agreement cements an architecture of hybrid multilateralism that enables and constrains non-state actor participation in global climate governance. We flesh out the constitutive features of hybrid multilateralism, enumerate the multiple positions non-state actors may employ under these conditions, and contend that non-state actors will play an increasingly important role in the post-Paris era. To substantiate these claims, we assess these shifts and ask how non-state actors may affect the legitimacy, justice, and effectiveness of the Paris Agreement

Building blocks: a strategy for near-term action within the new global climate framework

The Paris Agreement cemented a new framework for global climate policy based on the voluntary and non-legally binding emission reduction actions by both developed and developing countries. The building blocks strategy for climate action discussed in this Special Issue is well adapted to and strongly complements this new structure. Building blocks focus on multiple transnational mechanisms for mobilizing a wide range of both public and private actors to take actions that reduce emissions by capturing incentives other than climate mitigation as such. The initial commitments by countries under the Paris Agreement are insufficient to meet the level of action required to stabilize the global climate system at a safe level. As such, new voluntary action by public and private actors will be required. The building blocks strategy, and the examples presented in this Special Issue, offers answers to the question of how to generate and design smaller-scale initiatives

"Sunshade World": a fully coupled GCM evaluation of the climatic impacts of geoengineering

Sunshade geoengineering - the installation of reflective mirrors between the Earth and the Sun to reduce incoming solar radiation, has been proposed as a mitigative measure to counteract anthropogenic global warming. Although the popular conception is that geoengineering can re-establish a 'natural' pre-industrial climate, such a scheme would itself inevitably lead to climate change, due to the different temporal and spatial forcing of increased CO2 compared to reduced solar radiation. We investigate the magnitude and nature of this climate change for the first time within a fully coupled General Circulation Model. We find significant cooling of the tropics, warming of high latitudes and related sea ice reduction, a reduction in intensity of the hydrological cycle, reduced ENSO variability, and an increase in Atlantic overturning. However, the changes are small relative to those associated with an unmitigated rise in CO2 emissions. Other problems such as ocean acidification remain unsolved by sunshade geoengineering

Spectra of supernovae in the nebular phase

When supernovae enter the nebular phase after a few months, they reveal spectral fingerprints of their deep interiors, glowing by radioactivity produced in the explosion. We are given a unique opportunity to see what an exploded star looks like inside. The line profiles and luminosities encode information about physical conditions, explosive and hydrostatic nucleosynthesis, and ejecta morphology, which link to the progenitor properties and the explosion mechanism. Here, the fundamental properties of spectral formation of supernovae in the nebular phase are reviewed. The formalism between ejecta morphology and line profile shapes is derived, including effects of scattering and absorption. Line luminosity expressions are derived in various physical limits, with examples of applications from the literature. The physical processes at work in the supernova ejecta, including gamma-ray deposition, non-thermal electron degradation, ionization and excitation, and radiative transfer are described and linked to the computation and application of advanced spectral models. Some of the results derived so far from nebular-phase supernova analysis are discussed.Comment: Book chapter for 'Handbook of Supernovae,' edited by Alsabti and Murdin, Springer. 51 pages, 14 figure