GDP and employment effects of policies to close the 2020 emissions gap

Four policies might close the gap between the global GHG emissions expected for 2020 on the basis of current (2013) policies and the reduced emissions that will be needed if the long-term global temperature increase can be kept below the 2 °C internationally agreed limit. The four policies are (1) specific energy efficiency measures, (2) closure of the least-efficient coal-fired power plants, (3) minimizing methane emissions from upstream oil and gas production, and (4) accelerating the (partial) phase-out of subsidies to fossil-fuel consumption. In this article we test the hypothesis of the International Energy Agency (IEA) that these policies will not result in a loss of gross domestic product (GDP) and we estimate their employment effects using the E3MG global macro-econometric model. Using a set of scenarios we assess each policy individually and then consider the outcomes if all four policies were implemented simultaneously. We find that the policies are insufficient to close the emissions gap, with an overall emission reduction that is 30% less than that found by the IEA. World GDP is 0.5% higher in 2020, with about 6 million net jobs created by 2020 and unemployment reduced.

Policy relevance

The gap between GHG emissions expected under the Copenhagen and Cancun Agreements and that needed for emissions trajectories to have a reasonable chance of reaching the 2 °C target requires additional policies if it is to be closed. This article uses a global simulation model E3MG to analyse a set of policies proposed by the IEA to close the gap and assesses their macroeconomic effects as well as their feasibility in closing the gap. It complements the IEA assessment by estimating the GDP and employment implications separately by the different policies year by year to 2020, by major industries, and by 21 world regions.     

The role of salt in fold-and-thrust belts

The style of deformation in thin-skinned fold-and-thrust belts is critically dependent upon the resistance to sliding along the detachment between the mass of deforming sediments and the underlying rocks. Evaporites can provide an extremely weak horizon within which a basal detachment can form and along which only a relatively small shear traction can be supported. Fold-and-thrust belts that form atop a salt layer, such as the Appalachian Plateau, the Franklin Mountains in northwestern Canada, and the Jura of the Alps, among others, share several readily observable characteristics. As predicted by a simple mechanical model for fold-and-thrust belts, a detachment in salt permits a thrust belt to have an extremely narrow cross-sectional taper. In addition, predicted orientations of the principal stress axes over a salt décollement are consistent with the commonly observed lack of a consistently dominant vergence direction of structures within the thrust belt. Other common attributes of salt-basal thin-skinned deformation include the presence of several widely but regularly spaced folds and abrupt changes in deformational style at the edge of the salt basin.     

The 2dF Galaxy Redshift Survey: luminosity dependence of galaxy clustering

We investigate the dependence of the strength of galaxy clustering on intrinsic luminosity using the Anglo-Australian two degree field galaxy redshift survey (2dFGRS). The 2dFGRS is over an order of magnitude larger than previous redshift surveys used to address this issue. We measure the projected two-point correlation function of galaxies in a series of volume-limited samples. The projected correlation function is free from any distortion of the clustering pattern induced by peculiar motions and is well described by a power law in pair separation over the range     . The clustering of     galaxies in real space is well-fitted by a correlation length     and power-law slope     . The clustering amplitude increases slowly with absolute magnitude for galaxies fainter than M *, but rises more strongly at higher luminosities. At low luminosities, our results agree with measurements from the Southern Sky Redshift Survey 2 by Benoist et al. However, we find a weaker dependence of clustering strength on luminosity at the highest luminosities. The correlation function amplitude increases by a factor of 4.0 between     and −22.5, and the most luminous galaxies are 3.0 times more strongly clustered than L * galaxies. The power-law slope of the correlation function shows remarkably little variation for samples spanning a factor of 20 in luminosity. Our measurements are in very good agreement with the predictions of the hierarchical galaxy formation models of Benson et al.     

Volatile loss from melt inclusions in pyroclasts of differing sizes

We have investigated the loss of H₂O from olivine-hosted melt inclusions (MIs) by designing an experiment using tephra samples that cooled at different rates owing to their different sizes: ash, lapilli, and bomb samples that were deposited on the same day (10/17/74) of the sub-Plinian eruption of Volcán de Fuego in Guatemala. Ion microprobe, laser ablation-ICPMS, and electron probe analyses show that MIs from ash and lapilli record the highest H₂O contents, up to 4.4 wt%. On the other hand, MIs from bombs indicate up to 30 % lower H₂O contents (loss of ~1 wt% H₂O) and 10 % post-entrapment crystallization of olivine. This evidence is consistent with the longer cooling time available for a bomb-sized clast, up to 10 min for a 3–4-cm radius bomb, assuming conductive cooling and the fastest H diffusivities measured in olivine (D~10^?9 to 10^?10 m²/s). On the other hand, several lines of evidence point to some water loss prior to eruption, during magma ascent and degassing in the conduit. Thus, results point to both slower post-eruptive cooling and slower magma ascent affecting MIs from bombs, leading to H₂O loss over the timescale of minutes to hours. The important implication of this study is that a significant portion of the published data on H₂O concentrations in olivine-hosted MIs may reflect unrecognized H₂O loss via diffusion. This work highlights the importance of reporting clast and MI sizes in order to assess diffusive effects and the potential benefit of using water loss as a chronometer of magma ascent.     

MoisturEC: A New R Program for Moisture Content Estimation from Electrical Conductivity Data

Noninvasive geophysical estimation of soil moisture has potential to improve understanding of flow in the unsaturated zone for problems involving agricultural management, aquifer recharge, and optimization of landfill design and operations. In principle, several geophysical techniques (e.g., electrical resistivity, electromagnetic induction, and nuclear magnetic resonance) offer insight into soil moisture, but data‐analysis tools are needed to “translate” geophysical results into estimates of soil moisture, consistent with (1) the uncertainty of this translation and (2) direct measurements of moisture. Although geostatistical frameworks exist for this purpose, straightforward and user‐friendly tools are required to fully capitalize on the potential of geophysical information for soil‐moisture estimation. Here, we present MoisturEC, a simple R program with a graphical user interface to convert measurements or images of electrical conductivity (EC) to soil moisture. Input includes EC values, point moisture estimates, and definition of either Archie parameters (based on experimental or literature values) or empirical data of moisture vs. EC. The program produces two‐ and three‐dimensional images of moisture based on available EC and direct measurements of moisture, interpolating between measurement locations using a Tikhonov regularization approach.     

Trace elements and polycyclic aromatic hydrocarbons (PAHs) concentrations in deep Gulf of Mexico sediments

The concentrations of polycyclic aromatic hydrocarbons (PAHs) and trace elements were determined for surface (top 2 cm) sediment samples collected during the deep Gulf of Mexico benthos (DGoMB) study .These elements and compounds are known to be toxic to organisms at high concentrations and may affect biological communities. There is no indication of major anthropogenic input of the elements Be, Co, Cr, Fe, Si, Tl, V, K, Mg, Ca, Sr and Zn, based on normalization to Al. The concentrations of these metals in the sediment are a function of the relative amounts of trace-metal-rich Mississippi River-derived silicate material and trace-metal-poor plankton-derived carbonate. This is not true for the elements Ba, Ni, Pb, Cd, As, Cu and Mn, whose concentrations show considerable scatter when normalized to Al and a general enrichment. On a normalized basis, Mn is enriched 5–10 fold, Cu and Ni 2–3 fold and Pb 2 fold over Mississippi River-derived material. These enrichments are likely the result of remobilization of metals from depths in the sediment column where reducing conditions exist. The Ba concentrations at selected sites are higher than those of average clay-rich sediments, but are typical of sediments from near oil well platforms in the northern Gulf of Mexico. In the case of Ba, it seems likely that the enrichments, as high as a factor of 10, are due to disposal of oil well drilling mud. The Ba-enriched samples are from the three shallowest water sites in the Mississippi Trough (sites MT1, 2 and 3) and from site C1 and WC5. All are in an area of intense petroleum exploration and development. PAH concentrations are also elevated at MT1, MT3 and C1. The total PAH concentration ranged from not detected (ND) to 1033 ng/g with a mean of 140 ng/g. Even at the sites most enriched in PAHs and trace elements, the concentrations are not at the levels expected to adversely affect the biota. However, these predicted non-effects are based on research using mostly near-shore estuarine species, not on the indigenous species at the sampling sites.     

High‐frequency water quality monitoring in an urban catchment: hydrochemical dynamics,primary production and implications for the Water Framework Directive

This paper describes the hydrochemistry of a lowland, urbanised river‐system, The Cut in England, using in situ sub‐daily sampling. The Cut receives effluent discharges from four major sewage treatment works serving around 190 000 people. These discharges consist largely of treated water, originally abstracted from the River Thames and returned via the water supply network, substantially increasing the natural flow. The hourly water quality data were supplemented by weekly manual sampling with laboratory analysis to check the hourly data and measure further determinands. Mean phosphorus and nitrate concentrations were very high, breaching standards set by EU legislation. Although 56% of the catchment area is agricultural, the hydrochemical dynamics were significantly impacted by effluent discharges which accounted for approximately 50% of the annual P catchment input loads and, on average, 59% of river flow at the monitoring point. Diurnal dissolved oxygen data demonstrated high in‐stream productivity. From a comparison of high frequency and conventional monitoring data, it is inferred that much of the primary production was dominated by benthic algae, largely diatoms. Despite the high productivity and nutrient concentrations, the river water did not become anoxic, and major phytoplankton blooms were not observed. The strong diurnal and annual variation observed showed that assessments of water quality made under the Water Framework Directive (WFD) are sensitive to the time and season of sampling. It is recommended that specific sampling time windows be specified for each determinand, and that WFD targets should be applied in combination to help identify periods of greatest ecological risk. © 2015 The Authors. Hydrological Processes published by John Wiley & Sons Ltd.