The Effect of Green Investments in an Agent-Based Climate-Economic Model

Climate-economic modeling often relies on macroeconomic integrated assessment models (IAMs) that in general try to capture how the combined system reacts to different policies. Irrespective of the specific modeling approach, IAMs suffer from two notable problems. First, although policies and emissions are dependent on individual or institutional behavior, the models are not able to account for the heterogeneity and adaptive behavior of relevant actors. Second, the models unanimously consider mitigation actions as costs instead of investments: an arguable definition, given that all other expenditures are classified as investments. Both are challenging if the long-term development of climate change and the economy shall be analyzed. This paper therefore proposes a dynamic agent-based model, based on the battle of perspectives approach (Janssen [1]; Janssen and de Vries [2]; Geisendorf [3, 4]) that details the consequences of various behavioral assumptions. Furthermore, expenditures for climate protection, e.g., the transition of the energy system to renewables, are regarded as investments in future technologies with promising growth rates and the potential to incite further growth in adjoining sectors (Jaeger et al. [5]). The paper analyzes how a different understanding of climate protection expenditures changes the system’s dynamic and, thus, the basis for climate policy decisions. The paper also demonstrates how erroneous perceptions impact on economic and climate development, underlining the importance to acknowledge heterogeneous beliefs and behavior for the success of climate policy.     

Responses of juvenile European flounder (Platichthys flesus) to multistress in the Vilaine estuary, during a 6-month survey

Physiological and genetic responses of age 0+ Platichthys flesus were investigated in the eutrophicated and moderately contaminated Vilaine estuary, during a 6-month survey. The main objective of this study was to explore the biological responses of fishes during their juvenile period in an estuarine system in order to detect a possible selective pressure induced by the environmental stress. Our results showed a general convergence in physiological responses along the survey: an increase in genotoxicity was associated with an increase in mRNA expression of ATPase and betaine homocysteine methyltransferase. These results could suggest an increase of cellular damage, energetic request, and detoxification rate related to the growing exposure time to stress. Considering the aging of the cohort, the genetic characteristics of the Vilaine flounder cohort came closer to the one observed in a highly stressed system, the Seine estuary, suggesting a potential selective pressure mainly induced by the chemical stress.     

Structure and fate of a Pseudomonas aeruginosa population originating from a combined sewer and colonizing a wastewater treatment lagoon

The efficacy of a wastewater treatment lagoon (WWTL) at preventing the spread of Pseudomonas aeruginosa into natural aquatic habitats was investigated. A WWTL and its connected combined sewer and brook were exhaustively sampled. Physico-chemical analyses showed a stratification of the first pond according to pH, temperature and oxygen content. The P. aeruginosa counts partially matched this stratification with higher values among the bottom anaerobic waters of the first half of this pond. Genotyping of 494 WWTL P. aeruginosa strains was performed and led to the definition of 85 lineages. Dominant lineages were observed, with some being found all over the WWTL including the connected brook. IS5 was used as an indicator of genomic changes, and 1 to 12 elements were detected among 16 % of the strains. IS-driven lasR (genetic regulator) disruptions were detected among nine strains that were not part of the dominant lineages. These insertional mutants did not show significant elastase activities but showed better growth than the PAO1 reference strain in WWTL waters. Differences in growth patterns were related to a better survival of these mutants at an alkaline pH and a better ability at using some C-sources such as alanine. The opportunistic colonization of a WWTL by P. aeruginosa can involve several metabolic strategies which appeared lineage specific. Some clones appeared more successful than others at disseminating from a combined sewer toward the overflow of a WWTL.     

Comparison of oxygen-transfer measurement methods under process conditions.

The objective of this paper is to compare the following four methods of measuring oxygen transfer in wastewater treatment plants under process conditions: the offgas, hydrogen peroxide (H2O2), reaeration, and in situ oxygen uptake rate (OUR) methods. Comparative tests were performed under controlled conditions in a pilot column and in six full-scale oxidation ditches equipped with fine-bubble diffusers and slow-speed mixers. The offgas and H2O2 methods give similar results (differences between the oxygen-transfer coefficients under field conditions [k(L)a(f)] from each method lower than 10%). The reaeration procedure gives more random results (differences from -5 to -43% compared with values obtained using the offgas method). The in situ OUR method, in the presence of a horizontal flow of mixed liquor, leads to an estimate of k(L)a(f) to within 15% of the offgas value.     

Experimental values for 241Am and 239+240Pu Kd's in French agricultural soils

Experiments resulted in determination of K(d) values for (241)Am and (239+240)Pu in 6 soils whose characteristics are representative of agricultural soils found around French nuclear power plant sites. These experiments were conducted in stirred batch reactors and the sorption isotherms were plotted. For americium, the experimental K(d) values varied from 60 to 4000 Lkg(-1) (d.w.) and correlated well with soil pH, K(d) increased with increasing pH. As regards plutonium, the experimental K(d) values varied between 300 and 9600 Lkg(-1) and decreased with increasing total sand content. The estimation of the total residence time determined by using a particular and experimentally refined value for K(d)-with a model similar to those currently used for impact assessments-illustrates the importance of establishing values that are better suited to specific soils than generic values. Lastly, depending on the type of evaluation envisioned, it might be important to look for a specific value of K(d)-and even modelling-more suited to the specificity of the scenario studied, by performing more complex, or even in situ, experiments.     

Environmental risks of applying sewage sludge compost to vineyards: carbon,heavy metals,nitrogen, and phosphorus accumulation

Biosolids are applied to vineyards to supply organic matter. However, there is concern that this practice can increase the concentration of macronutrients and heavy metals in the soil, some of which can leach. We evaluated the environmental hazard of sewage sludge compost applied in March 1999 at 10, 30, and 90 Mg ha-1 fresh weight in a vineyard in southeastern France. Soil organic matter increased in all plots by 3 g kg-1 18 mo after the amendment. Neither total nor available heavy metal concentrations increased in the soil. Mineral nitrogen (N) in the topsoil of amended plots of 10, 30, and 90 Mg ha-1 increased by 5, 14, and 26 kg (NO3(-)-N + NH4(+)-N) ha-1, respectively, the first summer and by 2, 5, and 10 kg (NO3(-)-N + NH4(+)-N) ha-1, respectively, the second summer compared with controls. At the recommended rate, risks of N leaching is very low, but phosphorus (P) appeared to be the limiting factor. Phosphorus significantly increased only in plots amended with the highest rate in the topsoil and subsoil. At lower rates, although no significant differences were observed, P added was greater than the quantities absorbed by vines. In the long run, P will accumulate in the soil and may reach concentrations that will pose a risk to surface waters and ground water. Therefore, although the current recommended rate (10 Mg ha-1) increased soil organic matter without the risk of N leaching, total sewage sludge loading rates on vineyards should be based on P concentrations.     

Towards a framework for assessment and management of cumulative human impacts on marine food webs

Effective ecosystem‐based management requires understanding ecosystem responses to multiple human threats, rather than focusing on single threats. To understand ecosystem responses to anthropogenic threats holistically, it is necessary to know how threats affect different components within ecosystems and ultimately alter ecosystem functioning. We used a case study of a Mediterranean seagrass (Posidonia oceanica) food web and expert knowledge elicitation in an application of the initial steps of a framework for assessment of cumulative human impacts on food webs. We produced a conceptual seagrass food web model, determined the main trophic relationships, identified the main threats to the food web components, and assessed the components’ vulnerability to those threats. Some threats had high (e.g., coastal infrastructure) or low impacts (e.g., agricultural runoff) on all food web components, whereas others (e.g., introduced carnivores) had very different impacts on each component. Partitioning the ecosystem into its components enabled us to identify threats previously overlooked and to reevaluate the importance of threats commonly perceived as major. By incorporating this understanding of system vulnerability with data on changes in the state of each threat (e.g., decreasing domestic pollution and increasing fishing) into a food web model, managers may be better able to estimate and predict cumulative human impacts on ecosystems and to prioritize conservation actions.     

Using textile industrial sludge,sewage wastewater,and sewage sludge as inoculum to degrade recalcitrant textile dyes in a co-composting process: an assessment of biodegradation efficiency and compost phytotoxicity

Environmental Science and Pollution Research - Recalcitrant dyes found in textile wastewater represent a threat for sustainable textile production due to their resistance to conventional...