International Emission Trading and the Cost of Greenhouse Gas Emissions Mitigation and Sequestration

The deployment of carbon capture and sequestration (CC&S) technologies is greatly affected by the marginal cost of controlling carbon emissions (also the value of carbon, when emissions permits are traded). Both the severity and timing of emissions limitations and the degree to which emissions limitation obligations can be traded will affect the value of carbon and thereby the timing and magnitude of CC&S technology deployment. Emissions limits that are more stringent in the near term imply higher near-term carbon values and therefore encourage the local development and deployment of CC&S technologies.Trade in emissions obligations lowers the cost of meeting any regional or global emissions limit and so affects the rate of penetration of CC&S technologies. Trade lowers the marginal value of carbon and CC&S penetration in high cost regions and raises the marginal value of carbon and CC&S penetration in low cost regions. The net impact on the world CC&Stechnologies depends on whether their increased use in low-cost regions exceeds the reduced use in high-cost regions.In the long term, CC&S technologies must not only remove carbon but permanently sequester it. If reservoirs are not permanent, then the emissions and costs of control are merely displaced into the future. The paper presents quantitative estimates for the impacts of trade in emissions limitation obligations on the timing, magnitude, and geographic distribution of CC&S technologies and the marginal and total costs of carbon control.     

Particle geochemistry in the Rainbow hydrothermal plume, Mid-Atlantic Ridge

We report the analysis of 18 large volume (500-1500 L) in situ filtered samples of particulate material from the largest hydrothermal plume on the Mid-Atlantic Ridge, overlying the ultramafic-hosted Rainbow hydrothermal field at 36° 14′N. Measured particulate iron concentrations reach 614 nM. High concentrations of particulate Fe oxyhydroxides result from the extremely high Fe concentration (∼24 mM) and Fe/H₂S ratio (∼24) of the vent fluids, and persist to at least 10 km away from the vent site due to the advection of plume material with the ambient along-axis flow. Two of the nine pairs of pump deployments appear to have intercepted the buoyant or otherwise very young portion of the hydrothermal plume. These samples are characterized by anomalously (compared to neutrally buoyant plume samples) high concentrations of Mg, U, and chalcophile elements, and low concentrations of Mn, Ca, V, Y, and the rare earth elements (REE). Within the neutrally buoyant plume, elemental distributions are largely consistent with previously observed behaviors: preferential removal of chalcophile elements, conservative behavior of oxyanions (P, V, and U), and continuous scavenging of Y and the REE. This consistency is particularly significant in light of the underlying differences in fluid chemistry between Rainbow and other studied sites. Chalcophile elements are preferentially removed from the plume in the order Cd>Zn>Co>Cu. Phosphorus/iron and vanadium/iron ratios for the neutrally buoyant plume are consistent with global trends with respect to the concentration of dissolved phosphate in ambient seawater. Comparison of buoyant and neutrally buoyant plume ratios with data from hydrothermal sediments underlying the Rainbow plume (Cave et al., 2002) indicates, however, that while P/Fe ratios are indeed constant V/Fe ratios increase progressively from early stage plume particles to sediments. REE distributions in the buoyant and neutrally buoyant plume appear most consistent with a continuous scavenging process during dispersion through the water column.     

Core-based reconstruction of paleoenvironmental conditions in the southern Drake Passage (West Antarctica) over the last 150 ka

A deep-sea sediment core (GC98-06) from the southernmost Drake Passage, West Antarctica, shows late Quaternary depositional environments distinctly different from sedimentary drifts commonly found along the southwestern Pacific margin of the Drake Passage. The chronology of the core has been inferred using geochemical tracers of paleoproductivity and diatom biostratigraphy, and represents the paleoceanographic conditions in a continental rise setting during the last 150,000 years. Three dominant sediment types associated with distinct sedimentary processes have been identified using textural/compositional analyses: (1) hemipelagic mud (interglacial sediments) deposited from pelagic settling of bioclasts, meltwater plumes, and ice-rafted detritus; (2) terrigenous mud (glacial sediments) delivered by turbid meltwater plumes; and (3) massive muds marking the boundaries from interglacial to glacial periods. The succession of the sedimentary facies in core GC98-06 is interpreted to reflect temporal changes in environmental conditions prevailing on the continental rise of the southern Drake Passage in the course of successive climatic stages over the last 150 ka: from the bottom upward, these are glacial, interglacial, glaciation, glacial, and interglacial episodes. Variability in sediment flux and diatom abundance seem to have been related to changes in glacial advance, sea-ice extent, and specific sedimentary environments, collectively influenced by mid- to late Quaternary climatic changes.     

Sediment oxygen consumption in semi-closed Korean coastal bays during summer

We used an oxygen microsensor for high-resolution measurements of pore water oxygen concentration in semi-closed coastal bays of the South Sea of Korea during summer. The oxygen penetration depths ranged from 0.60 to 3.65 mm. Oxygen consumption rates were estimated to be 9.1 to 59 mmol m^?2 d^?1 (average: 22.8 mmol m^?2 d^?1). At the sediment-water interface, the oxidation rates of organic carbon were estimated to be 84–545 mg C m^?2 d^?1 (average: 211 mg C m^?2 d^?1). Approximately 38% (～211 mg C m^?2 d^?1) of pelagic primary production was regenerated in the surface sediment, indicating the tight benthic-pelagic coupling in the coastal sea of the South Sea of Korea.     

ARD generation and corrosion potential of exposed roadside rockmass at Boeun and Mujoo,South Korea

Acid rock drainage (ARD) is a longstanding problem often associated with the resulting corrosion due to the acidity generated from sulfidic oxidation. To evaluate characteristics of ARD and corrosion, samples from the road side rock mass of Boeun and Mujoo were analysed using X-ray diffraction, acid/base accounting and Leaching tests. The results indicated that many samples had a pyritic origin and can be regarded as acid-generating rocks. The Leaching test showed that the average pH of the leachates of samples from both Boeun and Mujoo were moderately acidic, ranging from 3 to 4. Interestingly, as acidity increases from pH 4, the SO₄₋, Fe, Al and Mg concentrations increase abnormally. Samples from roadside slope of Mujoo showed high corrosive potential. Maximum sulfide oxidation rate of a sample taken from Mujoo was as high as 5,166 mg/kg/week.     

Seasonal variations in pCO2 and its controlling factors in surface seawater of the northern East China Sea

Surface partial pressure of CO₂ (pCO₂), temperature, salinity, nutrients, and chlorophyll a were measured in the East China Sea (ECS; 31°30′–34°00′N to 124°00′–127°30′E) in August 2003 (summer), May 2004 (spring), October 2004 (early fall), and November 2005 (fall). The warm and saline Tsushima Warm Current was observed in the eastern part of the survey area during four cruises, and relatively low salinity waters due to outflow from the Changjiang (Yangtze River) were observed over the western part of the survey area. Surface pCO₂ ranged from 236 to 445 μatm in spring and summer, and from 326 to 517 μatm in fall. Large pCO₂ (values >400 μatm) occurred in the western part of the study area in spring and fall, and in the eastern part in summer. A positive linear correlation existed between surface pCO₂ and temperature in the eastern part of the study area, where the Tsushima Warm Current dominates; this correlation suggests that temperature is the major factor controlling surface pCO₂ distribution in that area. In the western part of the study area, however, the main controlling factor is different and seasonally complex. There is large transport in this region of Changjiang Diluted Water in summer, causing low salinity and low pCO₂ values. The relationship between surface pCO₂ and water stability suggests that the amount of mixing and/or upwelling of CO₂-rich water might be the important process controlling surface pCO₂ levels during spring and fall in this shallow region. Sea–air CO₂ flux, based on the application of a Wanninkhof [1992. Relationship between wind speed and gas exchange over the ocean. Journal of Geophysical Research 97, 7373–7382] formula for gas transfer velocity and a set of monthly averaged satellite wind data, were −5.04±1.59, −2.52±1.81, 1.71±2.87, and 0.39±0.18 mmol m⁻² d⁻¹ in spring, summer, early fall, and fall, respectively, in the northern ECS. The ocean in this study area is therefore a carbon sink in spring and summer, but a weak source or in equilibrium with the atmosphere in fall. If the winter flux value is assumed to have been the mean of autumnal and vernal values, then the northern ECS absorbs about 0.013 Pg C annually. That result suggests that the northern ECS is a net sink for atmospheric CO₂, a result consistent with previous studies.     

The origin and chemical form of arsenic in the school whiting

Arsenic concentrations were determined in the several stages of a short food chain culminating in school whiting (Sillago bassensis) from Waterman, Western Australia. Arsenic was shown to be present in school whiting as arsenobetaine. Analyses of plant material from Waterman suggest that the primary concentrator of arsenic from seawater is the brown kelp Ecklonia radiata. Analyses of trumpeter whiting (Sillago maculata) from Cockburn Sound, a semi-enclosed marine basin receiving arsenic-containing industrial effluents, reveal significantly lower levels of arsenic than school whiting from Waterman, an unpolluted environment.     

The impacts of climate change on local hydrology and low flow frequency in the Geum River Basin,Korea

The climate sensitive analysis of potential climate change on streamflow has been conducted using a hydrologic model to identify hydrologic variability associated with climate scenarios as a function of perturbed climatic variables (e.g. carbon dioxide, temperature, and precipitation). The interannual variation of water resources availability as well as low flow frequency driven by monsoonal time shifts have been investigated to evaluate the likelihood of droughts in a changing climate. The results show that the timing shift of the monsoon window associated with future climate scenarios clearly affect annual water yield change of ? 12 and ? 8% corresponding to 1‐month earlier and 1‐month later monsoon windows, respectively. Also, a more severe low flow condition has been predicted at 0·03 m³/s as opposed to the historic 7Q10 flow of 1·54 m³/s given at extreme climate scenarios. Copyright © 2011 John Wiley & Sons, Ltd.