Skip to main content
Advanced Search

Filters: Contacts: Zwerver, S. (X)

53 results (80ms)   

View Results as: JSON ATOM CSV
The seemingly irresistible growth of motorised transport and its environmental effects have led the NRP to also put mobility and transport (M & T) on its agenda. NRP questions are focused on psychosocial factors and mechanisms underlying the popularity of motorised transport, and on technical as well as behavioural measures and strategies to reduce global air pollution stemming from mobility and the use of motor vehicles. In Phase 1 of the programme, five NRP-funded Mssss & T projects have been conducted. Together with one or two related projects, these will be briefly summarised and commented upon. General observations, conclusions and some suggestions will be provided at the end of this paper.
Long-term greenhouse gas emission reduction strategies for the Netherlands were studied, using a MARKAL energy model. The EMS study identifies longterm technological options for greenhouse gas emission reduction and assesses their cost-effectiveness, taking interactions between technologies into account. The project consisted of three parts: carbon dioxyde (CO 2) emission reduction in the energy system, integrated reduction of greenhouse gases from the energy system with consideration of upstream emissions and CO 2 reduction in the integrated energy and materials system. 500 energy technologies were assessed for their reduction potential. Significant emission reduction seems possible, but it takes an array of measures...
The use of biomass crops as an energy source is frequently mentioned as an option to reduce CO 2 emissions. To evaluate the possibilities reliable yield estimates of biomass crops are required. In this paper a simple method is developed to estimate regional yields of various biomass crops, based on the linear relation between intercepted light and biomass production. The quality of the estimates was studied by using the method to estimate yields of several agricultural crops in two regions in The Netherlands. In general a deviation of less than 10 % was found between actual and estimated average yield.
In this paper part of an investigation is described into risks for climate change which are presently not adequately covered in General Circulation Models. The investigation included the interaction with biogeochemical cycles, the effects of clouds and aerosols, ice flow instability, albedo instability and modified ocean circulation. In this paper our results for clouds and aerosols and for biogeochemical cycles are reported.
In the projects fostered by the NRP the effects of changed climate (atmospheric CO2 concentration, temperature) on different terrestrial ecosystems were studied. For forests it was concluded that the initial stimulation of tree growth in general did not persist after two years, and therefore care must be taken not to overestimate the potential contribution of increased carbon sequestration by forests. On the other hand, shifted patterns of carbon distribution in the tree-soil system may lead to a higher soil organic matter content, which will contribute to an improved soil structure and availability of soil moisture. A sensitivity analysis revealed that, for the poor sandy forest soils, improved rooting depth is...
This report presents an overview and assessment of the three research projects carried out under NRP funding that concern risk-related topics: (1) The risks of nonlinear climate changes, (2) Socio-economic and policy aspects of changes in incidence and intensity of extreme (weather) events, and (3) Characterizing the risks: a comparative analysis of the risks of global warming and of relevant policy strategies.
Categories: Publication; Types: Citation; Tags: Assessment, Risk analysis, report
This article describes the development of an energy accounting. This is a management tool to give farmers a clear understanding of their energy use and of the emission of greenhouse gases on their farm. Results are given of one year accounting on dairy farms and on pig farms. The results show large differences in energy use and in emissions of greenhouse gases between individual farms. These differences indicate that a substantial reduction of emission of greenhouse gasses is possible.
The current project is aimed at developing a policy-oriented methodology for the integrated assessment of the global warming problem. Decision analysis in general and influence diagrams in particular appear to constitute an appropriate integrated assessment methodology. The influence-diagram approach is illustrated at a preliminary integrated modeling of the global warming problem. In next stages of the research, attention will be shifted from the methodology of integrated assessment to the contents of integrated models.
Past climate changes have led to considerable changes in the species composition of ecosystems. The recent increase in average global temperature is rather strong compared to previous warming periods and, if climate models are correct, future warming will be even stronger. Especially in Europe where the landscape has been greatly fragmented by human activities, the ongoing and projected changes in climate will pose an additional stress on the natural biodiversity. This paper will discuss a method for the selection of bio-indicators to assess the possible landscape-ecological effects of climate change, and presents some preliminary results of the selection of indicator species for the Netherlands.
Two field studies revealed large differences among various subgroups in the population of car drivers. Private drivers, commuters, and business drivers differed strongly with respect to current decisions and behaviour which affect CO2 emissions, and with respect to their sensitivity to various policy instruments. Several promising policy targets were identified" combinations of user groups and behaviours where substantial CO2 reduction may be achieved. The sensitivity of different car user groups to various policy measures showed whether and how desired behavioral changes may be realised.
Climate change results in an alteration of spatial and temporal patterns of climate hazards. The trend in weather related disaster seems upward. Various socio-economic sectors are affected by these changes, e.g. the disaster reduction institutions and the insurance industry. We report about an ongoing project addressing the vulnerabilities of sectors affected and policy options in various sectors, notably "Storms over NW-Europe", "the insurance sector" (both as a sector impacted by change and as a mechanism to cope with risk) and "cyclones in the South Pacific".
A new transportation demand model is described showing a simple data-base structure. It only requires input data referring to the fleets and the engine characteristics of the transportation park. The main characteristic of the model is its expertise in analysing the effects of different policies oriented to the reduction of the pollution levels and to the energy savings in the transportation sector. The results are provided both in terms of energy consumption and quantities of pollutant released to the environment. The effects of different transportation scenarios can be easily analysed using a simple "electronic sheet" way of representation.
In the projects fostered by the NRP the effects of changed climate (atmospheric CO2 concentration, temperature) on different terrestrial ecosystems were studied. For forests it was concluded that the initial stimulation of tree growth in general did not persist after two years, and therefore care must be taken not to overestimate the potential contribution of increased carbon sequestration by forests. On the other hand, shifted patterns of carbon distribution in the tree-soil system may lead to a higher soil organic matter content, which will contribute to an improved soil structure and availability of soil moisture. A sensitivity analysis revealed that, for the poor sandy forest soils, improved rooting depth is...
The relevance of econometric studies of ownership and use of private cars for environmental issues is sketched and some recent results are reviewed.
Our empirical material based on interviews with influental actors in environmental policy in Finland suggested that possible future climatic changes illustrates the greatest single environmental threat on a global scale. The influential actors did not hesitate to consider as an issue of high certainty a kind of man-induced climate change. In mapping out social resources among actors to tackle climatic risks we have utilizised a teleological reasoning of rational action as an ideal model.
Categories: Publication; Types: Citation; Tags: Climate change, environment, life
This article reflects the results of a study on sustainability of energy crops. Contribution to the reduction of the greenhouse effect and other environmental effects were investigated for the Netherlands. The study assumed that energy crops are grown on set aside or grain land. Generating electricity and/or heat from hemp, reed, miscanthus, poplar and willow have the best prospects. These crops are sustainable and may in the future be economically feasible. Ethanol from winter wheat has the most favourable environmental effects, but is economically not interesting. Liquid fuels from oil seed rape and sugar beet are not very sustainable.
The major part of the Netherlands consists of a low-lying river delta which is very sensitive to hydrological conditions in the North-Western part of the European continent. The rivers Rhine, Meuse and Scheldt carry through this delta to the North Sea annually nearly 100 km3 of fresh water. This water originates from a drainage basin of about 185 000 km2, which is 6 times the country area. The present geography of the Netherlands has largely been shaped by this river inflow and by the sediments which are carried along. Interaction of these fluxes with North Sea hydrodynamics in a period of rising sea level has produced large lowlands, which in the past millennium have been reclaimed for agricultural, urban and industrial...
Two field studies revealed large differences among various subgroups in the population of car drivers. Private drivers, commuters, and business drivers differed strongly with respect to current decisions and behaviour which affect CO2 emissions, and with respect to their sensitivity to various policy instruments. Several promising policy targets were identified" combinations of user groups and behaviours where substantial CO2 reduction may be achieved. The sensitivity of different car user groups to various policy measures showed whether and how desired behavioral changes may be realised.
Yields of winter wheat, silage maize and grain maize in the main arable areas of the European Union (E.U.) were calculated with a simulation model, WOFOST, using historical weather data and average soil characteristics. The sensitivity of the model to individual weather variables was determined.Subsequent analyses were made using climate change scenarios with and without the direct effects of increased atmospheric CO 2. The impact of crop management in a changed climate was also assessed. The various climate change scenarios used appear to yield considerably different changes in yield, both for each location and for the E.U. as a whole.
Research performed at the AB-DLO and the Free University was intended to quantify the effects of a doubled CO2 concentration on some key agronomic species and grasslands. A set of physiological and morphological processes was studied and related to above- and below ground cycling of carbon. The research was based on experiments and simulation studies at the level of plant, crop and soil in laboratory facilities and semi-field conditions with controlled CO2 supply. Agricultural crops were grown in "Open Top Chambers" or greenhouses and grasses in transparent tunnels made of Lexan. Soil processes and root respiration were studied in the Wageningen Rhizolab. Photosynthesis and assimilate partitioning were measured...