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This study highlights how Chinese economic development detrimentally impacted water quality in recent decades and how this has been improved by enormous investment in environmental remediation funded by the Chinese government. To our knowledge, this study is the first to describe the variability of surface water quality in inland waters in China, the affecting drivers behind the changes, and how the government-financed conservation actions have impacted water quality. Water quality was found to be poorest in the North and the Northeast China Plain where there is greater coverage of developed land (cities + cropland), a higher gross domestic product (GDP), and higher population density. There are significant positive relationships between the concentration of the annual mean chemical oxygen demand (COD) and the percentage of developed land use (cities + cropland), GDP, and population density in the individual watersheds (p < 0.001). During the past decade, following Chinese government-financed investments in environmental restoration and reforestation, the water quality of Chinese inland waters has improved markedly, which is particularly evident from the significant and exponentially decreasing GDP-normalized COD and ammonium (NH4+-N) concentrations. It is evident that the increasing GDP in China over the past decade did not occur at the continued expense of its inland water ecosystems. This offers hope for the future, also for other industrializing countries, that with appropriate environmental investments a high GDP can be reached and maintained, while simultaneously preserving inland aquatic ecosystems, particularly through management of sewage discharge.

It has long been established that mature forests are mosaics of patches in different development phases but it has seldom explicitly been taken into account in ecological studies. We demonstrate here that these development phases, which are related to the population dynamics of trees, play an important role in the distribution of fauna based on observations on frugivorous birds. In an area close to the Calakmul Biosphere Reserve in Mexico, we studied the abundance of large forest bird species in relation to forest development phases, with a methodology that seems promising for ecological diagnosis and prognosis in forest management planning. Fine-scale forest mapping and bird counts were carried out in two block-transects of 40 m x 3000 m. Tree sampling in a sub-transect was used to generate population characteristics of trees, Large bird species preferred mature or senescent forest patches, whereas relatively young, growing forest patches were avoided. Important large tree species such as Manilkara zapota, Thouinia paucidentata, Guaiacum sanctum and Esenbeckia pentaphylla, characteristic of older forest patches, showed skewed size distributions indicating stress or overexploitation. The population of M. zapota, a key fruiting species that accounted for 26.5% of the total woody biomass, was most heavily affected by stress. A future collapse in the population of M. zapota, a decrease of the total area of older forest, and a decline in the abundance of large birds is likely if stress on the system continues at this level. (C) 2008 Elsevier B.V. All rights reserved.

The South is likely to suffer more from climate change than the North due to its already vulnerable situation and lack of the necessary resources to adapt to change. But do the interests of men and of women differ as regards climate change and does this have a South-North dimension? This paper attempts to establish whether gender issues need to be addressed in the climate change debate. Towards this goal, a number of different issues within the climate change debate, in particular the instruments proposed, are analysed. These include responsibility for emission of greenhouse gases (GHGs), studies on vulnerability to the effects of climate change, mitigation of emissions, capacity building for participation in flexible mechanisms and adaptation to climate change. We conclude that while there are many gender angles related to the climate change convention and the instruments therein, some are more strategic than others. There is little to be gained by looking at the responsibility for emissions on a gendered basis. But in mitigation activities, Clean Development Mechanism (CDM), capacity building, technology transfer, vulnerability studies and projects for adaptation, the poor, the majority of who are women, should be targeted and active participants in decision-making.

A sudden and sharp rise in the C-14 content of the atmosphere, which occurred between ca. 850 and 760 calendar yr BC (ca. 2750-2450 BP on the radiocarbon time-scale), was contemporaneous with an abrupt climate change. In northwest Europe (as indicated by palaeoecological and geological evidence) climate changed from relatively warm and continental to oceanic. As a consequence, the ground-water table rose considerably in certain low-lying areas in The Netherlands. Archaeological and palaeoecological evidence for the abandonment of such areas in the northern Netherlands is interpreted as the effect of a rise of the water table and the extension of fens and bogs. Contraction of population and finally migration from these low-lying areas, which had become marginal for occupation, and the earliest colonisation by farming communities of the newly emerged salt marshes in the northern Netherlands around 2550 BP, is interpreted as the consequence of loss of cultivated land. Thermic contraction of ocean water and/or decreased velocity and pressure on the coast by the Gulf Stream may have caused a fall in relative sea-level rise and the emergence of these salt marshes. Evidence for a synchronous climatic change elsewhere in Europe and on other continents around 2650 BP is presented. Temporary aridity in tropical regions and a reduced transport of warmth to the temperate climate regions by atmospheric and/or oceanic circulation systems could explain the observed changes. As yet there is no clear explanation for this climate change and the contemporaneous increase of C-14 in the atmosphere. The strategy of C-14 wiggle-match dating can play an important role in the precise dating of organic deposits, and can be used to establish possible relationships between changing C-14 production in the atmosphere, climate change, and the impact of such changes on hydrology, vegetation, and human communities.

It is well known that the efficiency of PV modules decreases with increasing module temperatures. Many studies have paid attention to the development and validation of heuristic models to calculate the PV module temperature in higher latitudes, however only a few focus on the thermal behaviour of PV modules in tropical regions of the world, where constantly high temperatures prevail. Also, little is known about the effect of including wind speed in these thermal models. This study evaluates three of such models - one that excludes wind, and two others including the wind influence - using hourly data for two tropical locations. Results show that the average hourly wind speeds in Singapore and Jayapura (Indonesia) are low and therefore the influence of the wind on the PV module temperature is minor. The three evaluated models produce about the same results with RMSE between 1.5-3.8 °C during daytime, which corresponds to a deviation in power output in the range of 0.3-1.6 %, depending on the PV module technology.

AbstractThe potential impacts of future climate scenarios on water balance and flow regime are presented and discussed for a temporary river system in southern Italy. Different climate projections for the future (2030–2059) and the recent conditions (1980–2009) were investigated. A hydrological model (Soil and Water Assessment Tool) was used to simulate water balance at the basin scale and streamflow in a number of river sections under various climate change scenarios, based on different combinations of global and regional models (global circulation models and regional climate models). The impact on water balance components was quantified at the basin and subbasin levels as deviation from the baseline (1980–2009), and the flow regime alteration under changing climate was estimated using a number of hydrological indicators. An increase in mean temperature for all months between 0.5–2.4 °C and a reduction in precipitation (by 4–7%) was predicted for the future. As a consequence, a decline of blue water (7–18%) and total water yield (11–28%) was estimated. Although the river type classification remains unvaried, the flow regime distinctly moves towards drier conditions and the divergence from the current status increases in future scenarios, especially for those reaches classified as I‐D (ie, intermittent‐dry) and E (ephemeral). Hydrological indicators showed a decrease in both high flow and low flow magnitudes for various time durations, an extension of the dry season and an exacerbation of extreme low flow conditions. A reduction of snowfall in the mountainous part of the basin and an increase in potential evapotranspiration was also estimated (4–4.4%). Finally, the paper analyses the implications of the climate change for river ecosystems and for River Basin Management Planning. The defined quantitative estimates of water balance alteration could support the identification of priorities that should be addressed in upcoming years to set water‐saving actions.

Saving energy in greenhouses is an important issue for growers. Here, we present a method to minimize the total energy that is required to heat and cool a greenhouse. Using this method, the grower can define bounds for temperature, humidity, CO2 concentration, and the maximum amount of CO2 available. Given these settings, optimal control techniques can be used to minimize energy input. To do this, an existing greenhouse climate model for temperature and humidity was expanded to include a CO2 balance. Heating, cooling, the amount of natural ventilation, and the injection of industrial CO2 were used as control variables.Standard optimization settings were defined in order to compare the grower's strategy with the optimal solution. This optimization resulted in a theoretical 47% reduction in heating, 15% reduction in cooling, and 10% reduction in CO2 injection for the year 2012. The optimal control does not need to maintain a minimum pipe temperature, in contrast to current practice. When the minimum pipe temperature strategy of the grower was implemented, heating and CO2 were reduced by 28% and 10% respectively.We also analyzed the effect of different bounds on optimal energy input. We found that as more freedom is given to the climate variables, the higher the potential energy savings. However, in practice the grower is in charge of defining the bounds. Thus, the potential energy savings critically depend on the choice of these bounds. This effect was analyzed by varying the bounds. However, because the effect can be demonstrated to the grower, the outcome has value to the grower with respect to decision making, an option that is not currently available in practice today.

<div class="section abstract"><div class="htmlview paragraph">The introduction of new light-duty vehicle emission limits to comply under real driving conditions (RDE) is pushing the diesel engine manufacturers to identify and improve the technologies and strategies for further emission reduction. The latest technology advancements on the after-treatment systems have permitted to achieve very low emission conformity factors over the RDE, and therefore, the biggest challenge of the diesel engine development is maintaining its competitiveness in the trade-off “CO₂-system cost” in comparison to other propulsion systems. In this regard, diesel engines can continue to play an important role, in the short-medium term, to enable cost-effective compliance of CO₂-fleet emission targets, either in conventional or hybrid propulsion systems configuration. This is especially true for large-size cars, SUVs and light commercial vehicles.</div><div class="htmlview paragraph">In this framework, a comprehensive approach covering the whole powertrain is of primary importance in order to simultaneously meet the performance, efficiency, noise and emission targets, and therefore, further development of the combustion system design and injection system represent important levers for additional improvements. For this purpose, a dedicated 0.5 dm³ single-cylinder engine has been developed and equipped with, a state-of-the-art Euro 6 combustion system, and an advanced common rail fuel injection system (FIS) offering higher flexibility in terms of injection strategy and higher quantity accuracy. Three injector nozzles with different hydraulic flow rates (HF) have been selected and employed for the overall combustion process optimization.</div><div class="htmlview paragraph">The optimization has been performed by means of an extensive DoE-based test campaign in which the engine and FIS operating parameters have been parametrized with the aim to carry out a proper combination in terms of HF and injection strategy. The results at partial load conditions evidence significant advantages in applying an advanced injection pattern, while the HF reduction can significantly improve the smoke emission and combustion noise without fuel consumption penalties. Therefore, a proper combination and optimization of the HF and injection strategy can provide low noise and engine-out smoke while maintaining the rated power performance targets.</div></div>