Drivers of carbon dioxide emissions: an empirical investigation using hierarchical and non-hierarchical clustering methods

The mitigation of CO2 emissions requires a global effort with common but differentiated responsibilities. In this paper, we identify clusters of CO2 emissions across 72 countries. First, using the stochastic version of the IPAT and employing the dynamic common correlated effects technique, we identify three key determinants affecting CO2 emissions (non-renewables, population, and real GDP). In the second step, both hierarchical and non-hierarchical clustering methods are considered to identify the optimal number of clusters. We identify two to four clusters with different member countries, and in particular establish that in most cases, a 2-cluster solution appears to be optimal. The contents of clusters vary slightly according to the clustering methods for each period. The clustering results from using only the overall CO2 emissions indicate that the countries we consider form three clusters, with China and the USA each within a single member cluster. The remaining 70 countries form the third cluster. Our findings reflect the prominent roles of China and the USA in overall CO2 emissions. Analyses with sub-period and largest emitters reflect a different clustering structure. Some policy recommendations in setting emission reductions are made, considering different clusters across countries.     

Satellite Tracking of White-naped Crane Migration and the Importance of the Korean Demilitarized Zone

Satellite-tracking of 15 White-naped Cranes ( Grus vipio ) from their Japanese wintering grounds through the Korean Peninsula shows that there are four important regions for conserving migrant cranes: the Three Rivers Plain, the People's Republic of China; Lake Khanka, Russia; Kumya, North Korea; and—most importantly—the demilitarized zone of the Korean Peninsula. Two sites along the Korean demilitarized zone, Panmunch'om and Ch'olwon, were the most heavily used stopover sites, and they present complex international conservation challenges. Cranes stopped at these sites for up to 87.1% of their total migration time; cranes migrating to Zhalong Nature Reserve, China, made it their only lengthy stop. We report the migration routes and the importance of the identified stopover sites, and we outline conservation issues at those sites.     

Evaluation of antibiotic mobility in soil associated with swine-slurry soil amendment under cropping conditions

Interest in identifying pools of antibacterial-resistance genes has grown over the last decade, with veterinary antibiotics (VAs) receiving particular attention. In this paper, a mesoscale study aimed at evaluating the vertical transport of common VAs—namely, fluoroquinolones, tetracyclines, sulfonamides, and lincosamides in agricultural soil subjected to drip irrigation—was performed under greenhouse conditions. Accordingly, leachates of cropped and uncropped soil, amended with swine-slurry leading to 19–38 μg kg^?1 (dry mass) antibiotics in the soil, were analyzed over the course of the productive cycle of a lettuce (42 days) with three sampling campaigns (N?=?24). High lincomycin (LCM) concentrations (30–39 μg L^?1) were detected in the leachates collected from the swine-slurry-amended soil. The highest LCM mass recovered in the leachates (30.1?±?1.63 %) was obtained from cropped experimental units. In addition, the LCM leaching constant and its leaching potential as obtained from the first-order model were higher in the leachates from the cropped experimental units. Lower concentrations of sulfadimethoxine were also detected in leachates and in soil. Enrofloxacin and oxytetracycline occurred only in soil, which is consistent with high soil interaction.     

Oxidation of SO2 in Clouds at Whiteface Mountain

In-cloud oxidation of SO₂ byH₂O₂ was investigated using a tracertechnique based on SO^2– ₄/Se ratios atWhiteface Mountain, New York during summer months from1990 to 1998. Cloud water samples collected at themountain's summit (1.5 km above mean sea level) andaerosols at a below cloud site (Lodge) located at 0.6km amsl and in cloud interstitial air at the summitwere analyzed for SO^2– ₄ and selectedtrace elements. Gaseous SO₂ andH₂O₂were measured in realtime. Cloud water pH wasgenerally below 5.0 with a mean value of 3.6. Theresults show that significant in cloud oxidation occursin clouds during summer months varying from belowdetection to 62% with on average approximately 24% ofthe cloud water SO^2– ₄ produced from in-situ SO₂ oxidation. During summer the clouds wereoxidant limited for approximately one third of thetime.     

Nutrient transport through a Vegetative Filter Strip with subsurface drainage

The transport of nutrients and soil sediments in runoff has been recognized as a noteworthy environmental issue. Vegetative Filter Strips (VFS) have been used as one of the best management practices (BMPs) for retaining nutrients and sediments from surface runoff, thus preventing the pollutants from reaching receiving waters. However, the effectiveness of a VFS when combined with a subsurface drainage system has not been investigated previously. This study was undertaken to monitor the retention and transport of nutrients within a VFS that had a subsurface drainage system installed at a depth of 1.2 m below the soil surface. Nutrient concentrations of NO₃-N (Nitrate Nitrogen), PO₄⁻ (Orthophosphorus), and TP (Total Phosphorus) were measured in surface water samples (entering and leaving the VFS), and subsurface outflow. Soil samples were collected and analyzed for plant available Phosphorus (Bray P1) and NO₃-N concentrations. Results showed that PO₄⁻, NO₃-N, and TP concentrations decreased in surface flow through the VFS. Many surface outflow water samples from the VFS showed concentration reductions of as much as 75% for PO₄⁻ and 70% for TP. For subsurface outflow water samples through the drainage system, concentrations of PO₄⁻ and TP decreased but NO₃-N concentrations increased in comparison to concentrations in surface inflow samples. Soil samples that were collected from various depths in the VFS showed a minimal buildup of nutrients in the top soil profile but indicated a gradual buildup of nutrients at the depth of the subsurface drain. Results demonstrate that although a VFS can be very effective in reducing runoff and nutrients from surface flow, the presence of a subsurface drain underneath the VFS may not be environmentally beneficial. Such a combination may increase NO₃-N transport from the VFS, thus invalidating the purpose of the BMP.     

Bisphenol A content in fish caught in two different sites of the Tyrrhenian Sea (Italy)

Bisphenol A (BPA) is an endocrine disruptor (ED) that is abundant in the environment because of its extensive use in human-manufactured products. In this study, the BPA concentration was measured in the muscle and liver of five edible fish, characterized by different habitat and habits, caught in two different sites of the Tyrrhenian Sea (Italy). Our results show that: (i) fish livers are about 2.5 times more polluted than muscle; (ii) fish caught in the Gulf of Naples are more polluted than those from the Latium coasts, ranging from 1.2-fold more for White Bream to 6.6-fold for Grey Mullet; and (iii) the percentages of fish found to be BPA-polluted in the Gulf of Naples ranged from 73% (for Bass) to 90% (for Mullet), while the Latium fish range from 60% (for Bass) to 90% (for Mullet). These data indicate that consumers of fish caught in the Gulf of Naples are at a greater risk for BPA-induced endocrine pathologies compared to those who consume fish caught along the Latium coasts.     

Effect of bisphenol A with or without enzyme treatment on the proliferation and viability of MCF-7 cells

Recently, aqueous solutions polluted by BPA have been bioremediated by us using laccase immobilized on hydrophobic membranes in non-isothermal bioreactors. BPA degradation was checked using analytical methods. To assess in vitro the occurred bioremediation, the proliferation and viability indexes of MCF-7 cells incubated in the presence of aqueous solutions of BPA, or of enzyme-treated BPA solutions, have been measured as a function of the initial BPA concentration. The results demonstrated that: i) at each initial BPA concentration used, both the proliferation and viability indexes are a function of the duration of enzyme treatment; ii) proliferation and viability are uncoupled biological processes with respect to BPA enzyme treatment. Non-isothermal bioreactors are a useful tool for the bioremediation of aqueous solutions polluted by BPA, which is an example of an endocrine disruptor that belongs to the alkyl phenol family.     

Transforming time into money using water: A participatory study of economics and gender in rural India

When water supply improvements are coupled with opportunity to create income through micro–enterprises, time released from water collection is converted into income earned. This brings several benefits: reduced drudgery, higher household income, and, consequently, greater women's empowerment through changing gender relations within the household. This article documents the performance of one such scheme in Banaskantha District in the state of Gujarat in India, one of poorest districts in the state and the country. Here, due to the efforts of the Self–Employed Women's Association (SEWA), an Indian NGO, poor women are reaping the social and economic benefits of a government–run regional piped water supply scheme, a project funded by Dutch bilateral aid, focusing on women's development. If government policy–makers took the cue and formulated programmes and schemes that combined these two aspects, viz., actions that release time for rural women from daily chores (e.g., collecting water, fuel wood and fodder)and opportunities for sustainable micro–enterprises to convert time saved into income, this could become a reliable route out of rural poverty into gender–sensitive sustainable development.