Beyond Copenhagen: A Realistic Climate Policy in a Fragmented World

In this paper we argue that the financial provisions of the Copenhagen Accord, if used primarily to mitigate greenhouse gas (GHGs) emissions, could compensate the lack of more energetic action on the domestic mitigation side. In order to maximize the mitigation potential, the Copenhagen Green Climate Fund (CGCF) should be transformed into the International Bank for Emissions Allowance Acquisition (IBEAA) envisaged by Bradford ( 2008 ). We estimate that 50 percent of the CGCF in 2020 (50 US billions) could finance from 2.1 to 3.3 Gt CO2-eq emission reductions, depending on the domestic mitigation effort of Annex I and Non-Annex I countries. We construct a matrix that shows the level of GHGs emissions in 2020 under all possible combinations of abatement pledges and international mitigation financing, thus highlighting a rich set of options to reach the same level of GHGs emissions in 2020

Exploratory Analysis in Learning Analytics

This article summarizes the methods, observations, challenges and implications for exploratory analysis drawn from two learning analytics research projects. The cases include an analysis of a games-based virtual performance assessment and an analysis of data from 52,000 students over a 5-year period at a large Australian university. The complex datasets were analyzed and iteratively modeled with a variety of computationally intensive methods to provide the most effective outcomes for learning assessment, performance management and learner tracking. The article presents the research contexts, the tools and methods used in the exploratory phases of analysis, the major findings and the implications for learning analytics research methods

Textural and geochemical constraints on andesitic plug emplacement prior to the 2004–2010 vulcanian explosions at Galeras volcano, Colombia

Hazardous sequences of vulcanian explosions are thought to result from the repeated emplacement and destruction of degassed, highly crystalline magma plugs in the shallow conduit of arc volcanoes. The processes governing the timing and magnitude of these explosions are thought to be related to magma ascent rate and efficiency of degassing and crystallisation. We study a rare suite of time-constrained ballistic bombs from the 2004–2010 period of activity of Galeras volcano to reconstruct magma plug architecture prior to six individual vulcanian explosions. We find that each plug was vertically stratified with respect to crystallinity, vesicularity and melt volatile content, melt composition and viscosity. We interpret this structure as resulting from multiple bubble nucleation events and degassing-driven crystallisation during multi-step ascent of the magma forming the plug, followed by spatially variable crystallisation within the plug under contrasting conditions of effective undercooling created by degassing. We propose that the shallow conduit evolved from more open degassing conditions during 2004–2008 to more closed conditions during 2009–2010. This resulted in explosions becoming smaller and less frequent over time during 2004–2008, then larger and more frequent over time during 2009–2010. This evolution was controlled by changing average ascent rates and is recorded by systematic changes in plagioclase microlite textures. Our results suggest that small volume vulcanian explosions (~ 105 m3) should generally be associated with longer repose times (hundreds of days) and produce ballistics characterised by small numbers of large, prismatic plagioclase microlites. Larger volume vulcanian explosions (~ 106 m3) should be associated with shorter repose times (tens of days) and produce ballistics characterised by high numbers of small, more tabular plagioclase microlites

Transitions between explosive and effusive phases during the cataclysmic 2010 eruption of Merapi volcano, Java, Indonesia

Transitions between explosive and effusive activity are commonly observed during dome-forming eruptions and may be linked to factors such as magma influx, ascent rate and degassing. However, the interplay between these factors is complex and the resulting eruptive behaviour often unpredictable. This paper focuses on the driving forces behind the explosive and effusive activity during the well-documented 2010 eruption of Merapi, the volcano’s largest eruption since 1872. Time-controlled samples were collected from the 2010 deposits, linked to eruption stage and style of activity. These include scoria and pumice from the initial explosions, dense and scoriaceous dome samples formed via effusive activity, as well as scoria and pumice samples deposited during subplinian column collapse. Quantitative textural analysis of groundmass feldspar microlites, including measurements of areal number density, mean microlite size, crystal aspect ratio, groundmass crystallinity and crystal size distribution analysis, reveal that shallow pre- and syn-eruptive magmatic processes acted to govern the changing behaviour during the eruption. High-An (up to ∼80 mol% An) microlites from early erupted samples reveal that the eruption was likely preceded by an influx of hotter or more mafic magma. Transitions between explosive and effusive activity in 2010 were driven primarily by the dynamics of magma ascent in the conduit, with degassing and crystallisation acting via feedback mechanisms, resulting in cycles of effusive and explosive activity. Explosivity during the 2010 eruption was enhanced by the presence of a ‘plug’ of cooled magma within the shallow magma plumbing system, which acted to hinder degassing, leading to overpressure prior to initial explosive activity

Controls on explosive-effusive volcanic eruption styles

One of the biggest challenges in volcanic hazard assessment is to understand how and why eruptive style changes within the same eruptive period or even from one eruption to the next at a given volcano. This review evaluates the competing processes that lead to explosive and effusive eruptions of silicic magmas. Eruptive style depends on a set of feedbacks involving interrelated magmatic properties and processes. Foremost of these are magma viscosity, gas loss, and external properties such as conduit geometry. Ultimately, these parameters control the speed at which magmas ascend, decompress and outgas en route to the surface, and thus determine eruptive style and evolution

Non-emphysematous chronic obstructive pulmonary disease is associated with diabetes mellitus

Background: Chronic obstructive pulmonary disease (COPD) has been classically divided into blue bloaters and pink puffers. The utility of these clinical subtypes is unclear. However, the broader distinction between airway-predominant and emphysema-predominant COPD may be clinically relevant. The objective was to define clinical features of emphysema-predominant and non-emphysematous COPD patients. Methods: Current and former smokers from the Genetic Epidemiology of COPD Study (COPDGene) had chest computed tomography (CT) scans with quantitative image analysis. Emphysema-predominant COPD was defined by low attenuation area at -950 Hounsfield Units (LAA-950) ≥10%. Non-emphysematous COPD was defined by airflow obstruction with minimal to no emphysema (LAA-950 < 5%). Results: Out of 4197 COPD subjects, 1687 were classified as emphysema-predominant and 1817 as non-emphysematous; 693 had LAA-950 between 5-10% and were not categorized. Subjects with emphysema-predominant COPD were older (65.6 vs 60.6 years, p < 0.0001) with more severe COPD based on airflow obstruction (FEV1 44.5 vs 68.4%, p < 0.0001), greater exercise limitation (6-minute walk distance 1138 vs 1331 ft, p < 0.0001) and reduced quality of life (St. George's Respiratory Questionnaire score 43 vs 31, p < 0.0001). Self-reported diabetes was more frequent in non-emphysematous COPD (OR 2.13, p < 0.001), which was also confirmed using a strict definition of diabetes based on medication use. The association between diabetes and non-emphysematous COPD was replicated in the ECLIPSE study. Conclusions: Non-emphysematous COPD, defined by airflow obstruction with a paucity of emphysema on chest CT scan, is associated with an increased risk of diabetes. COPD patients without emphysema may warrant closer monitoring for diabetes, hypertension, and hyperlipidemia and vice versa