A review of climate geoengineering proposals

Climate geoengineering proposals seek to rectify the current radiative imbalance via either (1) reducing incoming solar radiation (solar radiation management) or (2) removing CO₂ from the atmosphere and transferring it to long-lived reservoirs (carbon dioxide removal). For each option, we discuss its effectiveness and potential side effects, also considering lifetime of effect, development and deployment timescale, reversibility, and failure risks. We present a detailed review that builds on earlier work by including the most recent literature, and is more extensive than previous comparative frameworks. Solar radiation management propsals are most effective but short-lived, whilst carbon dioxide removal measures gain effectiveness the longer they are pursued. Solar radiation management could restore the global radiative balance, but must be maintained to avoid abrupt warming, meanwhile ocean acidification and residual regional climate changes would still occur. Carbon dioxide removal involves less risk, and offers a way to return to a pre-industrial CO₂ level and climate on a millennial timescale, but is potentially limited by the CO₂ storage capacity of geological reservoirs. Geoengineering could complement mitigation, but it is not an alternative to it. We expand on the possible combinations of mitigation, carbon dioxide removal and solar radiation management that might be used to avoid dangerous climate change.     

源自海洋的地震风险

某些最强的地震源自遥远的海底断层。目前,地球物理学家正在铺设传感器网络,以密切监视这些"潜伏杀手"的动态。     

User fees and the permeability of public space at municipal pools and bathhouses in New York City, 1870 – present

This paper examines fees for access to New York City’s public swimming and bathing spaces from 1870 to the present. We argue that, beyond generating revenue and rationing space, charges for admission to public bathing spaces have served to condition how permeable those spaces were to various groups of potential users. Municipal actors involved in administering baths and pools have used fees to maintain and order these spaces; to distinguish between deserving and undeserving users; and to include and exclude participants in an ostensibly universal public. Over time, fees have been naturalized, erasing these motivations and giving cause to their outcomes. We problematize the fee in order to address both theoretical questions about the nature of public space and practical ones about how municipal administrators govern amidst competing pressures to serve, develop and regulate urban residents and their communities.     

Observations of dugongs at Aldabra Atoll,western Indian Ocean: lagoon habitat mapping and spatial analysis of sighting records

Until recently, it was thought that dugongs (Dugong dugon) were extinct in the Seychelles. However, a collection of sightings at Aldabra Atoll, a World Heritage Site in the Seychelles, has renewed interest in dugong distribution in the western Indian Ocean. This article consolidates the records of dugong sightings held in the Aldabra Research Station library and explores their spatial patterning. The locations of sightings (2001–2009) are plotted onto a high-resolution benthic habitat map of the Aldabra lagoon created by classifying a QuickBird satellite remote-sensing image in January 2009. A spatial cluster detection procedure is applied to point records of sightings to reveal a statistically significant cluster of sightings in the north-west of the lagoon, at Bras Monsieur Clairemont, suggesting a mutual co-existence of dugongs and seagrass beds. A habitat suitability model combines the point data set of dugong sightings within the continuous benthic habitat map and identifies the central western area as containing the most suitable habitat for dugong inside the Aldabra lagoon.     

Uptake and biological effects of synthetic glucocorticoids in common carp (Cyprinus carpio)

Uptake and biological effects of synthetic glucocorticoids (GCs) were analyzed using common carp (Cyprinus carpio). Fish were exposed to clobetasol propionate (CP) or clobetasone butyrate (CB) individually or in mixture at 1 μg L⁻¹ for 21 days. Bioconcentration factor (BCF) of CB was calculated as 100, and BCF of CP was less than 16. No effects were found in fish erythrocyte and leukocyte numbers and serum glucose levels after exposure to the selected GCs. On the other hand, serum concentrations of free amino acids significantly increased in GC-exposed groups. Thus, exposures to synthetic GCs at relatively low concentrations seemed to cause enhancement of protein degradation and subsequent increase of serum free amino acids without a corresponding increase in serum glucose levels, an effect which might be related to partial induction of gluconeogenesis by GC.     

A photometric analysis of the active chromosphere star GT Muscae

GT Mus is a quadruple system containing an RS CVn-type binary and a pair of eclipsing A dwarfs. More than four years of continuous BV(RI)_c photometry of the system has revealed spot-wave variability in the active component of the RS CVn binary. The amplitude and mean level of this spot wave change with time in an activity cycle. An infrared excess was also observed from time to time and this has been interpreted as hydrogen emission from flare events. The system is therefore remarkable for showing four different types of variability, all on different time-scales, and three of these associated with the active star.     

Horizontal displacements in Japan

Recent horizontal displacements in Japan are discussed by using the results of the first-order triangulation surveys. Large horizontal displacements are found in East Hokkaido, Tohoku, South Kanto, Tokai and Nankai districts (Fig.1). Crustal activity in these districts is also briefly discussed. The original triangulation survey in Japan neglected Laplace (azimuth) observations and consequently rotation and divergence around the assumed fixed point often appear as horizontal displacements. This is especially true in the central Japan where horizontal displacements result from cancelling the apparent rotation and divergence around the assumed fixed point (Fig.2).On the other hand, strain measurements avoid such shortcoming. Considering with the results of the first triangulation, the horizontal earth-strain can be calculated for every subsequent triangulation net. It is interesting that the velocity of the maximum shear strain is almost 2–3 · 10^/t7/year throughout Japan (Fig.3), even though the seismic activities show large regional discrepancies.     

Neutron Activation Analysis of Nine GSJ Sedimentary Rock Reference Samples

Nine rock reference samples "Sedimentary rock series" issued by the Geological Survey of Japan (GSJ) were analysed for up to 31 elements by neutron activation analysis (NAA); 14MeV-NAA for Si and Al, fission track method for U, radiochemical and instrumental NAA for rare-earth elements, and instrumental NAA for the remaining elements, with reactor neutrons for the latter three. The present results are compared with reported values.