PROGRESS IN ESTIMATING THE MARGINAL COSTS OF GREENHOUSE GAS EMISSIONS

The unjust distributional consequences of climate change, and its potentially negative aggregate effect on economic growth and welfare are two reasons to be concerned about climate change. Our knowledge of the impact of climate change is incomplete. Monetary valuation is difficult and controversial. The effect of other developments on the impacts of climate change is largely speculative. Nonetheless, it can be shown that poorer countries and people are more vulnerable than are richer countries and people. A modest global warming is likely to have a net negative effect on poor economics in hot climates, but may have a positive effect on rich economies in temperate climates. If one counts dollars, the world aggregate impact may be positive. If one counts people, the world aggregate effect is probably negative. For more substantial warming, negative effects become more negative, and positive effects turn negative. The marginal costs of carbon dioxide emissions are uncertain and sensitive to assumptions that partially reflect ethical and methodological positions, but are unlikely to exceed $50 per tonne of carbon. The marginal costs of methane emission are likely to be less than$250/tCH4; the marginal costs of nitrous oxide emissions are probably lower than $7000/tN2O. Global warming potentials, the official manner to trade-off the various greenhouse gases, do not reflect, conceptually or numerically, the real tradeoffs in either a cost-benefit or a cost-effectiveness framework.Impacts of climate change, economic valuation, equity, marginal costs

The key physical parameters governing frictional dissipation in a precipitating atmosphere

Precipitation generates small-scale turbulent air flows the energy of which ultimately dissipates to heat. The power of this process has previously been estimated to be around 2-4 W m-2 in the tropics: a value comparable in magnitude to the dynamic power of the global circulation. Here we suggest that this previous power estimate is approximately double the true figure. Our result reflects a revised evaluation of the mean precipitation path length Hp. We investigate the dependence of Hp on surface temperature,relative humidity,temperature lapse rate and degree of condensation in the ascending air. We find that the degree of condensation,defined as the relative change of the saturated water vapor mixing ratio in the region of condensation, is a major factor determining Hp. We estimate from theory that the mean large-scale rate of frictional dissipation associated with total precipitation in the tropics lies between 1 and 2 W m-2 and show that our estimate is supported by empirical evidence. We show that under terrestrial conditions frictional dissipation constitutes a minor fraction of the dynamic power of condensation-induced atmospheric circulation,which is estimated to be at least 2.5 times larger. However,because Hp increases with surface temperature Ts, the rate of frictional dissipation would exceed that of condensation-induced dynamics, and thus block major circulation, at Ts >~320 K in a moist adiabatic atmosphere.Comment: 12 pp, 2 figure

hp-adaptive Galerkin Time Stepping Methods for Nonlinear Initial Value Problems

This work is concerned with the derivation of an a posteriori error estimator for Galerkin approximations to nonlinear initial value problems with an emphasis on finite-time existence in the context of blow-up. The structure of the derived estimator leads naturally to the development of both h and hp versions of an adaptive algorithm designed to approximate the blow-up time. The adaptive algorithms are then applied in a series of numerical experiments, and the rate of convergence to the blow-up time is investigated

Altering Parameters of CRISPR/Cas9 Mediated Genome Editing in Escherichia coli Helps Identify Sources of Variation in Editing Efficiency

CRISPR/Cas9, originating from a bacterial immune system, has been identified as a powerful tool for genome modification (Jinek, et al., 2012). Historically, analyzing genotype-phenotype relationships have been limited by DNA synthesis and sequencing technology. Recent developments in genome editing (CRISPR/Cas9) coupled to improvements in synthesis and sequencing allows mapping these relationships at an entirely new scale. A technique novel to the Gill lab for genome modification that harnesses the CRISPR-Cas system is “CRISPR Enabled Trackable Genomic Engineering” or “CREATE” technology. CREATE technology is one such strategy for simultaneously making hundreds of thousands of single genomic edits, then tracking the resultant phenotypes. In this study, I alter parameters of the CREATE mechanism to elucidate the cause of variability in editing efficiency between different editing constructs. I demonstrate that editing efficiency is impacted by guide RNA toxicity, genomic position, expression levels of Cas9, availability of template for homologous recombination, and expression levels of phage-based recombination proteins. I find that high toxicity is related to high editing efficiency. The position of the gene being edited in the bacterial genome impacts editing efficiency in a pattern dependent on guide toxicity. Expression levels of Cas9 also affect editing efficiency in a guide toxicity-dependent fashion. Additional results studying recombination suggest increasing intracellular abundance of donor DNA can lead to increased editing efficiency, in a genomic position-specific manner. A final finding was that expressing recombination proteins using a constitutive promoter replicated the behavior of the traditional lambda Red expression system, opening up possibilities for future modifications

Sustainable Land Use: Methodology and Application

The chapters in this volume are edited versions of papers presented at the NATO Ad- vanced Research Workshop on Environmental Change Adaptation and Security held in Budapest, Hungary, from October 16 - 18, 1997. As is evident in this volume, the papers ranged from descriptions of environmental and health issues in Russia and Eastern Europe to models of sustainable land use. This diversity of perspectives on environ- ment and security is indicative of both the breadth of this new area of research as well as the varied background of the researchers involved. The discussions at the NATO workshop were remarkably animated and exciting, not surprising given the interest in the topic. I think this vitality is reflected in the papers in this volume as well. The main purpose of the NATO ARW is to foster research links among researchers from NATO countries and Central and Eastern European States, Russia, and the Newly Independent States. In editing this volume, a decision was made to keep to the spirit of this purpose and-if at all possible-include all papers prepared for the workshop. This required extensive editing and rewriting of some of the papers (and consequent delays in production). A determination was made early in the process by the workshop steering committee that the value of publishing the entire collection of articles out- weighed the advantages of accepting only a limited number

Climate policy and ancillary benefits : a survey and integration into the modelling of international negotiations on climate change

Currently informal and formal international negotiations on climate change take place in an intensive way since the Kyoto Protocol expires already in 2012. A post-Kyoto regulation to combat global warming is not yet stipulated. Due to rapidly increasing greenhouse gas emission levels, industrialized countries urge major polluters from the developing world like China and India to participate in a future agreement. Whether these developing countries will do so, depends on the prevailing incentives to participate in international climate protection efforts. This paper identifies ancillary benefits of climate policy to provide important incentives to attend a new international protocol and to positively affect the likelihood of accomplishing a post-Kyoto agreement which includes commitments of developing countries

Preclinical mouse models of immune checkpoint inhibitor-associated myocarditis

In this Review, we present a comprehensive analysis of preclinical models used to study immune checkpoint inhibitor-associated myocarditis (hereafter ICI-myocarditis), a potentially lethal immune-related adverse event. We begin by providing an overview of immune checkpoint inhibitors, highlighting how their efficacy in cancer treatment is counterbalanced by their predisposition to cause immune-related adverse events. Next, we draw from human data to identify disease features that an effective mouse model should ideally mimic. After that, we present a critical evaluation of a wide variety of existing mouse models including genetic, pharmacological and humanized models. We summarize insights gathered about the underlying mechanisms of ICI-myocarditis and the role of mouse models in these discoveries. We conclude with a perspective on the future of preclinical models, highlighting potential model improvements and research directions that could strengthen our understanding of ICI-myocarditis, ultimately improving patient outcomes