THE DUODENAL FLOW OF ORGANIC MATTER AND NITROGEN IN DAIRY COWS RECEVING FRESH HERBAGE FERTILIZED AT TWO LEVELS OF NITROGEN

van Vuuren, A.M.,Krol-Kramer, F.,Eisses, J.T. Asian Australasian Association of Animal Productio 1989 Animal Bioscience Vol.2 No.3

The Shared Socioeconomic Pathways and their energy, land use, and greenhouse gas emissions implications: An overview

Riahi, Keywan,van Vuuren, Detlef P.,Kriegler, Elmar,Edmonds, Jae,O’Neill, Brian C.,Fujimori, Shinichiro,Bauer, Nico,Calvin, Katherine,Dellink, Rob,Fricko, Oliver,Lutz, Wolfgang,Popp, Alexander,Cuaresm Elsevier 2017 Global environmental change Vol.42 No.-

<P><B>Abstract</B></P> <P>This paper presents the overview of the Shared Socioeconomic Pathways (SSPs) and their energy, land use, and emissions implications. The SSPs are part of a new scenario framework, established by the climate change research community in order to facilitate the integrated analysis of future climate impacts, vulnerabilities, adaptation, and mitigation. The pathways were developed over the last years as a joint community effort and describe plausible major global developments that together would lead in the future to different challenges for mitigation and adaptation to climate change. The SSPs are based on five narratives describing alternative socio-economic developments, including sustainable development, regional rivalry, inequality, fossil-fueled development, and middle-of-the-road development. The long-term demographic and economic projections of the SSPs depict a wide uncertainty range consistent with the scenario literature. A multi-model approach was used for the elaboration of the energy, land-use and the emissions trajectories of SSP-based scenarios. The baseline scenarios lead to global energy consumption of 400–1200 EJ in 2100, and feature vastly different land-use dynamics, ranging from a possible reduction in cropland area up to a massive expansion by more than 700 million hectares by 2100. The associated annual CO<SUB>2</SUB> emissions of the baseline scenarios range from about 25 GtCO<SUB>2</SUB> to more than 120 GtCO<SUB>2</SUB> per year by 2100. With respect to mitigation, we find that associated costs strongly depend on three factors: (1) the policy assumptions, (2) the socio-economic narrative, and (3) the stringency of the target. The carbon price for reaching the target of 2.6W/m<SUP>2</SUP> that is consistent with a temperature change limit of 2°C, differs in our analysis thus by about a factor of three across the SSP marker scenarios. Moreover, many models could not reach this target from the SSPs with high mitigation challenges. While the SSPs were designed to represent different mitigation and adaptation challenges, the resulting narratives and quantifications span a wide range of different futures broadly representative of the current literature. This allows their subsequent use and development in new assessments and research projects. Critical next steps for the community scenario process will, among others, involve regional and sectoral extensions, further elaboration of the adaptation and impacts dimension, as well as employing the SSP scenarios with the new generation of earth system models as part of the 6th climate model intercomparison project (CMIP6).</P> <P><B>Highlights</B></P> <P> <UL> <LI> We present an overview of the Shared Socioeconomic Pathways (SSPs), which were developed as a community effort over the last years. </LI> <LI> The SSPs comprise five narratives and a set of driving forces. </LI> <LI> Our SSP scenarios quantify energy and land-use developments and associated uncertainties for greenhouse gas and air pollutant emissions. </LI> <LI> We conduct an SSP mitigation analysis, and estimate mitigation costs. We find that very low climate targets might be out of reach in SSPs featuring high challenges. </LI> <LI> The SSPs are now ready for use by the climate change research community. </LI> </UL> </P>

The impact of near-term climate policy choices on technology and emission transition pathways

Eom, J.,Edmonds, J.,Krey, V.,Johnson, N.,Longden, T.,Luderer, G.,Riahi, K.,Van Vuuren, D.P. American Elsevier 2015 TECHNOLOGICAL FORECASTING AND SOCIAL CHANGE Vol.90 No.1

This paper explores the implications of delays (to 2030) in implementing optimal policies for long-term transition pathways to limit climate forcing to 450ppm CO<SUB>2</SUB>e on the basis of the AMPERE Work Package 2 model comparison study. The paper highlights the critical importance of the period 2030-2050 for ambitious mitigation strategies. In this period, the most rapid shift to low greenhouse gas emitting technology occurs. In the delayed response emission mitigation scenarios, an even faster transition rate in this period is required to compensate for the additional emissions before 2030. Our physical deployment measures indicate that the availability of CCS technology could play a critical role in facilitating the attainment of ambitious mitigation goals. Without CCS, deployment of other mitigation technologies would become extremely high in the 2030-2050 period. Yet the presence of CCS greatly alleviates the challenges to the transition particularly after the delayed climate policies, lowering the risk that the long-term goal becomes unattainable. The results also highlight the important role of bioenergy with CO<SUB>2</SUB> capture and storage (BECCS), which facilitates energy production with negative carbon emissions. If BECCS is available, transition pathways exceed the emission budget in the mid-term, removing the excess with BECCS in the long term. Excluding either BE or CCS from the technology portfolio implies that emission reductions need to take place much earlier.

Biophysical and economic limits to negative CO₂ emissions

Smith, Pete,Davis, Steven J.,Creutzig, Felix,Fuss, Sabine,Minx, Jan,Gabrielle, Benoit,Kato, Etsushi,Jackson, Robert B.,Cowie, Annette,Kriegler, Elmar,van Vuuren, Detlef P.,Rogelj, Joeri,Ciais, Philipp Nature Publishing Group 2016 Nature climate change Vol.6 No.1

<P>To have a >50% chance of limiting warming below 2 degrees C, most recent scenarios from integrated assessment models (IAMs) require large-scale deployment of negative emissions technologies (NETs). These are technologies that result in the net removal of greenhouse gases from the atmosphere. We quantify potential global impacts of the different NETs on various factors (such as land, greenhouse gas emissions, water, albedo, nutrients and energy) to determine the biophysical limits to, and economic costs of, their widespread application. Resource implications vary between technologies and need to be satisfactorily addressed if NETs are to have a significant role in achieving climate goals.</P>

Locked into Copenhagen pledges - Implications of short-term emission targets for the cost and feasibility of long-term climate goals

Riahi, K.,Kriegler, E.,Johnson, N.,Bertram, C.,den Elzen, M.,Eom, J.,Schaeffer, M.,Edmonds, J.,Isaac, M.,Krey, V.,Longden, T.,Luderer, G.,Mejean, A.,McCollum, D.L.,Mima, S.,Turton, H.,van Vuuren, D.P. American Elsevier 2015 TECHNOLOGICAL FORECASTING AND SOCIAL CHANGE Vol.90 No.1

This paper provides an overview of the AMPERE modeling comparison project with focus on the implications of near-term policies for the costs and attainability of long-term climate objectives. Nine modeling teams participated in the project to explore the consequences of global emissions following the proposed policy stringency of the national pledges from the Copenhagen Accord and Cancun Agreements to 2030. Specific features compared to earlier assessments are the explicit consideration of near-term 2030 emission targets as well as the systematic sensitivity analysis for the availability and potential of mitigation technologies. Our estimates show that a 2030 mitigation effort comparable to the pledges would result in a further ''lock-in'' of the energy system into fossil fuels and thus impede the required energy transformation to reach low greenhouse-gas stabilization levels (450ppm CO<SUB>2</SUB>e). Major implications include significant increases in mitigation costs, increased risk that low stabilization targets become unattainable, and reduced chances of staying below the proposed temperature change target of 2<SUP>o</SUP>C in case of overshoot. With respect to technologies, we find that following the pledge pathways to 2030 would narrow policy choices, and increases the risks that some currently optional technologies, such as carbon capture and storage (CCS) or the large-scale deployment of bioenergy, will become ''a must'' by 2030.