Social dilemmas,policy instruments,and climate adaptation measures: the case of green roofs

Green roofs contribute to both climate change adaptation and mitigation. Promoting green roofs is thus a key element in urban strategies to address climate change. How to actually promote green roofs, however, has so far proven elusive: attempts to link specific policy instruments to a more or less successful diffusion of green roofs have been few and far between. The present paper relies on institutional economics to advance the present understanding of the link between policy instruments and green roofs. It argues that different green roofs are confronted with different social dilemmas, and thus require different policy instruments. Specifically, small green roofs face a free-rider problem, which is best addressed through regulations and incentives. Large green roofs face instead a collective action problem, which is best addressed through communications and network-building. This perspective is tested empirically through a comparative analysis of 18 global cities on the forefront in the promotion of green roofs. The policy instruments observed in these cities match with the theoretical expectations laid down in the paper. Implications emerge for both policy and research.

     

Agricultural policies and the emergence of voluntary landscape enhancement efforts: an exploratory analysis of rural tourism using an agent-based model

Conservation and enhancement of ecosystem services have become a priority of rural policies. Feedback loops from rural policies on ecosystem service supply have often been highlighted in the literature, but only vaguely investigated. In this paper, we model feedback loops from rural policies through an agent-based model, and we analyse whether feedback loops can indirectly create a system in which voluntarily landscape enhancement emerges from the interactions between farmers and rural tourists. The results suggest that, in certain conditions, feedback loops from policies can be a relevant element to take into account, but that greater attention to the ecosystem service demand is required.     

An overview of experimental results and dispersion modelling of nanoparticles in the wake of moving vehicles

Understanding the transformation of nanoparticles emitted from vehicles is essential for developing appropriate methods for treating fine scale particle dynamics in dispersion models. This article provides an overview of significant research work relevant to modelling the dispersion of pollutants, especially nanoparticles, in the wake of vehicles. Literature on vehicle wakes and nanoparticle dispersion is reviewed, taking into account field measurements, wind tunnel experiments and mathematical approaches.Field measurements and modelling studies highlighted the very short time scales associated with nanoparticle transformations in the first stages after the emission. These transformations strongly interact with the flow and turbulence fields immediately behind the vehicle, hence the need of characterising in detail the mixing processes in the vehicle wake. Very few studies have analysed this interaction and more research is needed to build a basis for model development. A possible approach is proposed and areas of further investigation identified.     

Effect of aging on catalytic properties in mechanochemical degradation of pentachlorophenol by birnessite

Mechanochemistry, a technique concerning with milling contaminated samples for prolonged times, induces massive degradation of pollutants by grinding them in ball mills with different soil components or additives. In the present study, laboratory experiments were conducted to evaluate the effect of aging on the mechanochemical efficiency of the Mn-oxide birnessite in degrading pentachlorophenol (PCP). A comparative study on an aged birnessite (KBiA), used after 3 years from synthesis, and a fresh birnessite (KBiF), employed immediately after synthesis, was carried out. The differences between the two birnessites, evidenced by spectroscopic and diffractometric techniques, are mainly relative to reduction of the Mn(IV) centered at the MnO₆ octahedra layers from the birnessite structure, which represent the most reactive sites for PCP degradation. The long term air drying at room temperature, by favouring reduction of Mn(IV) to Mn(III), produces an inorganic substrate that offers paucity of the less reactive sites for PCP degradation, thus reducing the oxidative potential of the KBiA. Accordingly, the more reactive fresh birnessite was employed in the experiment with a polluted soil. Adding a small amount of KBiF to soil only induces a light increase in PCP removal, probably due to the mechanically induced PCP adsorption and transformation onto clay minerals present in the soil. Besides, adding a higher dose of birnessite causes a stronger degradation of PCP.     

Maternal environment and the expression of murine neural tube defects

The role that genetic and environmental factors play in triggering neural tube defects in the mouse mutant curly-tail (ct) were investigated by transplanting curly-tail blastocysts into the uterus of either curly-tail females or females of an unrelated A strain with a low natural incidence of abnormalities of the neural tube. The percentages of fetuses with neural tube defects were found to be similar in both groups. These results show that in curly-tail mice exencephaly and spina bifida are manifested independently of the maternal environment.     

Male lagoon gobies, <Emphasis Type="Italic">Knipowitschia panizzae</Emphasis>, prefer more ornamented to larger females

Female ornamentation may be directly sexually selected, by male choice or female competition, or occurs as the result of a genetic correlation, arising from sexual selection on males. However, increasing evidence supports the former hypothesis, suggesting that males actively choose their partner preferring traits indicative of female quality. In the lagoon goby, Knipowitschia panizzae, a polygynous species whose males perform parental care to eggs, body length and the size of a sex-specific yellow patch on the belly are known to be reliable indicators of female fecundity. In this paper, we tested, using dummies, the male’s mating preferences for female body and yellow belly patch sizes. The two experimental trials in which a single female trait was variable showed that males prefer a larger belly patch and a larger body size, indicating that both these characters are selected by male mate choice. However, when faced with dummies exhibiting an inverse combination of body and belly patch sizes (experiment 3), males significantly preferred the smaller ones with larger yellow belly patches. A calculation of dummy theoretical fecundity reveals that in the first two experiments, males would have received an immediate benefit from their choice in terms of egg number, whereas in the third one, males chose partners that would have provided them with fewer eggs. The male lagoon goby preference for females with larger belly patches, regardless of their size, suggests that this trait, in addition to indicating fecundity, conveys information about other aspects of female and/or egg quality.     

Microchipped bags and waste sorting

Environmental Economics and Policy Studies - We evaluate the effectiveness of attaching microchips to bags for curbside collection in reducing unsorted urban solid waste and increasing the fraction...