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A number of black box and process-based modelling approaches, their strengths/limitations, and future applications for simulating contaminant dynamics in constructed wetlands (CWs) have been reviewed. Scanning of literature reveals that most of the CW modelling approaches are limited to the simulation of only nutrient and organic pollutant load dynamics. Performance analysis of the various process/black box-based models for simulating pollutant dynamics in vertical subsurface flow, horizontal subsurface flow, and hybrid CW systems further reveals that most of the existing modelling approaches have not not so far been able to account for the changing climatic conditions and the heavy metal dynamics. The paper thus highlights the gaps in the knowledge in the current state of the art for simulating wetland pollutant dynamics and suggests mechanisms for increasing the scope of such modelling approaches in the proper design and operation of the CW systems. [ABSTRACT FROM PUBLISHER]

Recently, climate engineering and particularly sulphur aerosol injection (SAI) have entered the arena of international climate change politics. The idea behind SAI is very simple: to reflect sunlight and heat back into space by injecting particles into the stratosphere. SAI has the theoretical potential to moderate anthropogenic climate change in a timely fashion and at very low costs but may also cause major environmental harm. Determining the future of SAI will entail dealing with many major uncertainties such as assessing risks, costs and benefits. This paper critically investigates scientific knowledge production under conditions of major uncertainty. It discusses how uncertainty, ethics and social considerations are treated in the SAI literature, which applies techno-economic models. In the simplest studies, important uncertainties are excluded from the models, but the more complex studies include many uncertainties, which may have considerable influence on the results and recommendations. In some cases the modelled results are overshadowed or strengthened by ethical discussions or methodological reflexivity that emphasize uncertainties and model limitations. There seems to be ambivalence between constructing certainty, on one hand, and an awareness of methodological limitations, on the other. Finally, the value of these papers for decision-makers and other concerned groups is discussed. [ABSTRACT FROM AUTHOR]

Model-based decision support systems are increasingly used to link knowledge to action for environmental decision making. How stakeholders perceive uncertainty in models and visualisations affects their perceptions of credibility, relevance and usability of these tools. This paper presents a case study of water decision makers’ evaluations of WaterSim, a dynamic water simulation model presented in an immersive decision theatre environment. Results reveal that decision makers’ understandings of uncertainty in their evaluations of decision support systems reflect both scientific and political discourse. We conclude with recommendations for design and evaluation of decision support systems that incorporate decision makers' views. [ABSTRACT FROM AUTHOR]

Global flood management is a major issue for most cities which have to deal with worsening factors such as climate change and fast urban growth. Computer models have been used to model and understand urban flooding on a local scale in cities (25–50 km2). It has been practically impossible to model bigger cities in one go in sufficiently high resolution due to the heavy computations involved. The present paper describes a new modelling approach for urban flooding which allows modelling on large city scale (1000 km2) while keeping sufficient resolution, e.g. 5 m or 10 m grid. The multicell approach is applied for the city of Beijing for July 21st, 2012 flood event. Model results are compared to testimonials from the 2012 event. Comparison to traditional 2D urban flood computations shows that the multicell approach is much faster than standard detailed models while keeping a suitable level of precision. [ABSTRACT FROM AUTHOR]

Tourism results in the emission of climate-changing greenhouse gases. There has been limited destination-focused quantitative analysis of how tourism might be reshaped to reduce these emissions. This paper uses an extended tourism environmental satellite account methodology to examine the case of tourism in Wales, a United Kingdom region. It shows how an estimate of the emissions associated with trips to, and in, the region – internally, from the rest of the UK and from abroad – can contribute to regional aspirations to reduce greenhouse gas emissions. The analysis suggests that substantial emissions cuts are dependent upon technical developments outside of tourism itself. Four potential scenarios are devised and analysed. Scenario 1 shows the value of low carbon electricity production in cutting tourism-related emissions. Scenario 2 analyses a possible 50% fall in international arrivals and 10% increase in UK domestic arrivals – maintaining employment but reducing emissions. Scenario 3 shows the effects of switch from private to public transport modes for 50% of UK resident arrivals. Scenario 4 examines the outcomes of reducing ground transport emissions by using electric, biofuel and hybrid technologies. All scenarios cut emissions, none are highly effective and most are dependent on changes in society and governance. [ABSTRACT FROM AUTHOR]

Climate change is expected to affect food and feed safety, including the occurrence of natural toxins in primary crop and seafood production; however, to date, quantitative estimates are scarce. This study aimed to estimate the impact of climate change effects on mycotoxin contamination of cereal grains cultivated in the terrestrial area of north west Europe, and on the frequency of harmful algal blooms and contamination of shellfish with marine biotoxins in the North Sea coastal zone. The study focused on contamination of wheat with deoxynivalenol, and on abundance of Dinophysis spp. and the possible relationship with diarrhetic shellfish toxins. The study used currently available data and models. Global and regional climate models were combined with models of crop phenology, mycotoxin prediction models, hydrodynamic models and ecological models, with the output of one model being used as input for the other. In addition, statistical data analyses using existing national datasets from the study area were performed to obtain information on the relationships between Dinophysis spp. cell counts and contamination of shellfish with diarrhetic shellfish toxins as well as on frequency of cereal cropping. In this paper, a summary of the study is presented, and overall conclusions and recommendations are given. Climate change projections for the years 2031–2050 were used as the starting point of the analyses relative to a preceding 20-year baseline period from which the climate change signal was calculated. Results showed that, in general, climate change effects lead to advanced flowering and harvest of wheat, and increased risk of contamination of wheat with deoxynivalenol. Blooms of dinoflagellates were estimated to occur more often. If the group of Dinophysis spp. behaves similarly to other flagellates in the future then frequency of harmful algal blooms of Dinophysis spp. may also increase, but consequences for contamination of shellfish with diarrhetic shellfish toxins are uncertain. Climate change will also have indirect effects on toxin contamination, which may be equally important. For example, the frequency of cropping of wheat and maize in north Europe was projected to increase under climate change, which will also increase the risk of contamination of the grains with deoxynivalenol. Risk managers are encouraged to consider the entire range of the predictions of climate change effects on food safety hazards, rather than median or average values only. Furthermore, it is recommended to closely monitor levels of mycotoxins and marine biotoxins in the future, in particular related to risky situations associated with favourable climatic conditions for toxin producing organisms. In particular, it is important to pay attention to the continuity of collecting the right data, and the availability and accessibility of databases. On a European level, it is important to stress the need for harmonisation of terminology and data collection. [ABSTRACT FROM PUBLISHER]