128 research outputs found

    Het Atmosfeer-Oceaan Modelsysteem van het IMAGE-model. Achtergrondrapport van het mondiale modelsysteem voor bepaling van concentraties, klimaatverandering en zeespiegelstijging

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    In this report, we describe the technical background of the Atmosphere Ocean System (AOS) of the Integrated Model to Assess the Global Environment (IMAGE, version 2.2). The AOS submodel elaborates the global concentrations of the most important greenhouse gases and ozone precursors, along with their direct and indirect effects on global-mean radiative forcing. These submodels are based on state-of-the-art approximations, as published by the Intergovernmental Panel on Climate Change (IPCC) in its Third Assessment Report (TAR). That these simple submodels can adequately reproduce the global concentrations and forcings of more complex models in a very short runtime is also true for the simple climate submodel for calculating the consequences for the climate system and sea-level rise described in this report. We also elaborate on the scientific background and the most important features of the different submodels, comparing the results with other models and observations. Furthermore, we demonstrate that AOS adequately represents the 1970-1995 period for the main global indicators (concentrations, temperature increase and sea-level rise).Dit rapport beschrijft de technische achtergrond van het atmosfeer-oceaan systeem van het IMAGE-model (Integrated Model to Assess the Global Environment). Het atmosfeer-oceaan systeem van IMAGE modelleert de atmosferische concentraties van de meest belangrijke broeikasgassen en de directe en indirecte effecten van die gassen op de stralingsbalans. Deze submodellen zijn gebaseerd op state-of-the-art benaderingen van meer complexe modellen, zoals gepubliceerd in de Third Assessment Report van het IPCC (Intergovernmental Panel on Climate Change). Dit geldt ook voor het eenvoudige klimaatmodel, wat in dit rapport wordt beschreven en wat de mondiaal gemiddelde klimaatverandering en zeespiegelstijging berekent. Naast de belangrijkste kenmerken van de submodellen, wordt ook de meest relevante wetenschappelijke achtergrond geschetst. Eveneens worden voor een aantal mondiale indicatoren de resultaten vergeleken met observaties en resultaten van meer complexe modellen en wordt aangetoond voor deze indicatoren dat het atmosfeer-oceaan systeem in de periode 1970 - 1995 goed benadert. Elk hoofdstuk wordt afgesloten met projecties tot 2100 volgens de SRES scenario's van het IPCC, zoals die door het IMAGE team in 2001 zijn gepubliceerd

    Climate simulation of the twenty-first century with interactive land-use changes

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    To include land-use dynamics in a general circulation model (GCM), the physical system has to be linked to a system that represents socio-economy. This issue is addressed by coupling an integrated assessment model, IMAGE2.2, to an ocean¿atmosphere GCM, CNRM-CM3. In the new system, IMAGE2.2 provides CNRM-CM3 with all the external forcings that are scenario dependent: greenhouse gas (GHGs) concentrations, sulfate aerosols charge and land cover. Conversely, the GCM gives IMAGE changes in mean temperature and precipitation. With this new system, we have run an adapted scenario of the IPCC SRES scenario family. We have chosen a single scenario with maximum land-use changes (SRES A2), to illustrate some important feedback issues. Even in this two-way coupled model set-up, land use in this scenario is mainly driven by demographic and agricultural practices, which overpowers a potential influence of climate feedbacks on land-use patterns. This suggests that for scenarios in which socio-economically driven land-use change is very large, land-use changes can be incorporated in GCM simulations as a one-way driving force, without taking into account climate feedbacks. The dynamics of natural vegetation is more closely linked to climate but the time-scale of changes is of the order of a century. Thus, the coupling between natural vegetation and climate could generate important feedbacks but these effects are relevant mainly for multi-centennial simulations

    Vleesconsumptie en klimaatbeleid

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    In deze studie wordt de mogelijke invloed van dieetveranderingen op de kosten van ambitieuze klimaatdoelstellingen verkend. Doel van de studie is uitsluitend om in te schatten wat de wereldwijde bijdrage van dieetverandering kan zijn. De vleesconsumptie wordt aangepast in vier varianten van dieetverandering: GeenHerkauwers (geen vlees van herkauwers), GeenVlees (geheel geen vlees), GeenDierproducten (geen enkel dierlijk product) en WilettDieet (een 'gezond' dieet). Hiervoor wordt het geïntegreerde model IMAGE (Integrated Model to Assess the Global Environment) gebruikt. Ook worden resultaten voor landgebruik en biodiversiteit gegeve

    Global impacts of European agricultural and biofuel policies

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    Food supply and food distribution have been and are important issues in the global political arena. The recent emergence of biofuel policies has increased the influence of the policy arena on agricultural production. In this paper we show the regional impact of changes in the European Common Agricultural Policy and biofuel policy. Shifting trade patterns, changes in agricultural production, and expansion of agricultural area or intensification of agriculture result in changes in land use and land use emissions. Higher prices for agricultural crops on the world market together with changing production raise agricultural income. Brazil is the region the most affected. The results show that arrangements or policies will be needed to avoid negative impacts in other regions of changing agricultural or biofuel policies in the European Union

    De kleine vraagbaak van het Kyoto Protocol : vragen en antwoorden over ontstaan, inwerkingtreding en uitvoering van het Kyoto Protocol

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    Bij gelegenheid van de officiële inwerkingtreding van het Kyoto-protocol hebben Wageningen UR, KNMI, RIVM, NWO, VU en ECN een handzaam boekje uitgegeven met antwoorden op alle vragen die u maar over de zin en onzin van Kyoto kunt bedenken. Het boekje legt uit wat het protocol inhoudt en wat het betekent voor milieu, economie en samenleving. Ook het jargon dat door klimaatonderzoekers en in het internationale onderhandelingscircuit wordt gebruikt, wordt in begrijpelijke bewoordinge

    Quantifying the effectiveness of climate change mitigation through forest plantations and carbon sequestration with an integrated land-use model

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    <p>Abstract</p> <p>Background</p> <p>Carbon plantations are introduced in climate change policy as an option to slow the build-up of atmospheric carbon dioxide (CO<sub>2</sub>) concentrations. Here we present a methodology to evaluate the potential effectiveness of carbon plantations. The methodology explicitly considers future long-term land-use change around the world and all relevant carbon (C) fluxes, including all natural fluxes. Both issues have generally been ignored in earlier studies.</p> <p>Results</p> <p>Two different baseline scenarios up to 2100 indicate that uncertainties in future land-use change lead to a near 100% difference in estimates of carbon sequestration potentials. Moreover, social, economic and institutional barriers preventing carbon plantations in natural vegetation areas decrease the physical potential by 75–80% or more.</p> <p>Nevertheless, carbon plantations can still considerably contribute to slowing the increase in the atmospheric CO<sub>2 </sub>concentration but only in the long term. The most conservative set of assumptions lowers the increase of the atmospheric CO<sub>2 </sub>concentration in 2100 by a 27 ppm and compensates for 5–7% of the total energy-related CO<sub>2 </sub>emissions. The net sequestration up to 2020 is limited, given the short-term increased need for agricultural land in most regions and the long period needed to compensate for emissions through the establishment of the plantations. The potential is highest in the tropics, despite projections that most of the agricultural expansion will be in these regions. Plantations in high latitudes as Northern Europe and Northern Russia should only be established if the objective to sequester carbon is combined with other activities.</p> <p>Conclusion</p> <p>Carbon sequestration in plantations can play an important role in mitigating the build-up of atmospheric CO<sub>2</sub>. The actual magnitude depends on natural and management factors, social barriers, and the time frame considered. In addition, there are a number of ancillary benefits for local communities and the environment. Carbon plantations are, however, particularly effective in the long term. Furthermore, plantations do not offer the ultimate solution towards stabilizing CO<sub>2 </sub>concentrations but should be part of a broader package of options with clear energy emission reduction measures.</p
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