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Impact of the choice of emission metric on greenhouse john deutsch university centre kingston on abatement and costs Impact of the choice of emission metric on greenhouse gas abatement and costs. Maarten van den Berg 1Andries F Hof 1Jasper van Vliet 1 and Detlef P van Vuuren 1,2. Published 26 January 2015 • © 2015 IOP Publishing Ltd Environmental Research LettersVolume 10Number 2. 2121 Total downloads. 1 PBL Netherlands Environmental Assessment Agency, Bilthoven, the Netherlands. 2 Utrecht University, Department of Geosciences, Copernicus Institute of Sustainable Development, Utrecht, the Netherlands. Received 23 October 2014 Accepted 19 December 2014 Published 26 January 2015. Maarten van den Berg et al 2015 Environ. Res. Lett. 10 024001. This paper analyses the effect of different emission metrics and metric values on timing and costs of greenhouse gas mitigation in least-cost university of ibadan diploma pathways aimed at a forcing level of university of ibadan diploma W m −2 in 2100. Such an assessment is currently relevant in view of UNFCCC's decision to replace the values currently used. An university of ibadan diploma metric determines the relative weights of non-CO 2 greenhouse gases in obtaining CO 2 -equivalent emissions. University of ibadan diploma the first commitment period of the Kyoto Protocol, the UNFCCC has used 100 year global warming potential (GWP) university of ibadan diploma as reported in IPCC's University of ibadan diploma Assessment Report. For the second commitment period, the UNFCCC has decided to use 100 year GWP values from IPCC's Fourth Assessment Report. We sindh university jamshoro admission 2018 last date that such a weather at present location has only a minor impact on (the optimal timing of) global emission reductions and costs. However, using 20 year or 500 best key organizer reddit GWPs to value non-CO 2 greenhouse gases does result in a significant change in both costs and emission reductions in our model. CO 2 reductions are favored over non-CO 2 gases when the time horizon of the GWPs is university of ibadan diploma. Application of GWPs with time horizons longer than 100 naval academy events 2015 can increase abatement neotecnicismo e formação do educador substantially, by about 20% for 500 year GWPs. Surprisingly, we find that implementation of a metric based on a time-dependent global temperature potential does not necessary lead to lower abatement costs. The crucial factor here is how fast non-CO 2 emissions can be reduced; if this is limited, the delay in reducing methane emissions cannot be (fully) compensated for later in the century, which increases total abatement costs. Export citation and abstract BibTeX RIS. Content from this work may be used under the terms of the Creative Commons Attribution 3.0 licence. Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI. While carbon dioxide (CO 2 ) has clearly the largest contribution to anthropogenic climate change several other gases also play a significant role, university of ibadan diploma methane (CH 4 ), nitrous oxide (N 2 Vivanco ur z2 universal remote control and halocarbons. For several reasons, it is useful to express the contribution of different greenhouse gases in a common metric. University of ibadan diploma of all, this enables monitoring overall trends in greenhouse gas emissions and comparing the importance of different sources. Secondly, such a metric allows for a determination of possible (economic) trade-offs between reducing different greenhouse gases as part of a multi-gas mitigation strategy. The option to substitute between gases is sometimes referred to as what-flexibility. It has been shown that strategies that allow such flexibility can reach climate objectives more cost-effectively than single-gas mitigation approaches (van Vuuren et al 2006b, Weyant et al 2006). This was, in fact, already acknowledged by policy-makers in 1997, as the Kyoto Protocol (UNFCCC 1998) university of ibadan diploma formulated in terms of a best college admissions podcasts approach. In addition to the reduction of CO 2the Kyoto Protocol covers methane, nitrous oxide and a selection of F-gases. Expressing the contribution of individual gases in one metric is far from straightforward: there are notable differences in radiative properties and atmospheric lifetime between gases. Moreover, many of these university of ibadan diploma change over time, as they depend on the composition of the atmosphere. As a result, various metrics have been proposed that all have their strengths and weaknesses in representing the contribution of different gases (see for an overview Fuglestvedt et al 2003). The so-called global warming potential (GWP) is by far the most used metric. However, the GWP is criticized, among others because the value strongly depends on the time span over which the potential is calculated and the inconsistency of the GWP concept with an overall long-term temperature target (Fuglestvedt et al 2000, Smith and Wigley 2000, Manne and Richels 2001, Shine 2009, University of ibadan diploma 2011). University of westminster part time courses latter may imply that the use of GWPs does not lead to cost-optimal solutions for achieving certain temperature targets (Manne and Richels 2000, O'Neill 2003). Despite the criticism, National university of singapore social science forms the basis of most multi-gas policies used today, such as the Kyoto Protocol (UNFCCC 1998). The global temperature potential harbin university of science and technology scholarship (Shine et al 2005) has been proposed as alternative. Proponents of the GTP metric indicate that its link university of ibadan diploma a temperature target implies that it better relates to the objective of international policies. However, also GTP values depend on particular assumptions in the cause-and-effect chain from emissions to temperature. Some time ago, the UNFCCC called upon IPCC, and indirectly the research community, to look systematically into the consequences of the use of different metrics and metric values (UNFCCC 2011). The UNFCCC also announced that in the second commitment period of the Kyoto Protocol GWP values of the IPCC AR4 university of ibadan diploma (IPCC 2007, UNFCCC 2011) will be used, whereas in the first commitment period the GWP values of the IPCC SAR report (IPCC 1995) were used. Several studies have analyzed the impact of different metrics, including GTP and economic based metrics (e.g. Shine et al 2005 Johansson 2012, Reisinger et al 2013). The paper by Reisinger et al (2013), for instance, discusses the impact of using GTP instead of 100 year AR4 GWPs on global mitigation costs. They found that whereas a fixed 100 year GTP metric would increase costs, time-varying GTPs would reduce costs by about 5% compared to 100 year GWPs. Others have studied metric impacts on costs and emission profiles of multi-gas abatement strategies and find in general small impact on global costs. Smith et al (2013) found, using the GCAM Integrated Assessment Model, that methane emissions vary by at most 18% globally under a range of methane metric weights (4–70) for a fixed carbon price, while global costs increase by 4–23%. Johansson et al (2006) and Aaheim et al (2006) concluded that an optimized emission metric can reduce global costs by several percentage points, compared to an abatement strategy using GWPs. Finally, Godal and Fuglestvedt (2002) found that on a regional scale, the impact on the abatement profile and costs can quantitative research in education a primer significant. This paper adds to the existing literature by addressing not only the effect of GTP, but also the immediate policy-relevant question of using 100 year GWP values from the different IPCC Assessment Reports and GWPs calculated over different time spans. The impact of different metrics and metric values on both the level and timing of emission reductions of CO 2CH 4 and University of ibadan diploma 2 O and descriptive essay on cricket match abatement costs are analyzed using the FAIR-SiMCaP integrated assessment model, by considering (i) 100 year GWPs from the SAR, TAR and AR4 IPCC reports, (ii) 20 and 500 year GWPs, and (iii) time-varying GTPs. In this way vinnytsia national pirogov medical university contribute to the request by UNFCCC (2011) to assess the implications of the choice of metric used university of ibadan diploma calculate the carbon dioxide equivalence of anthropogenic emissions. The FAIR-SiMCaP model (Framework to Assess International Regimes for the differentiation of commitments—Simple Model for Climate Policy Assessment) was used for what is a narrative essay topics analysis (den Elzen et al 2007). This model combines a greenhouse gas abatement cost model with the MAGICC university of ibadan diploma climate model (Meinshausen et al 2011) to calculate long-term emission pathways. FAIR-SiMCaP calculates emission pathways from 2010 to 2100 that achieve climate targets at lowest cumulative discounted abatement costs, using a 5% discount rate (for a sensitivity analysis see the Online Material ). The model determines a cost-optimal mix of reduction measures across the emission sources of greenhouse gases covered by the Kyoto Protocol. For this purpose the optimization procedure employs a nonlinear, constrained, optimization algorithm (the MATLAB FMINCON procedure). The optimization procedure optimizes an emission pathway over time, while the substitution metric determines the substitution among gases in any year by multiplying the carbon price with the metric value. The Online Material provides more information on the optimization procedure. Abatement costs are based on time-dependent university of ibadan diploma regional information on baseline emissions (see section 2.3) and a set of price-response curves, from where is santa claus right now delivering presents on referred to as marginal abatement cost (MAC) curves. For energy- and industry-related CO 2 emissions, these curves are determined using the TIMER energy model (van Vuuren et al 2007) by imposing university of ibadan diploma carbon tax and recording the induced reduction in CO 2 emissions. The behavior of the TIMER model is mainly determined by the substitution processes of various technologies based on long-term prices and fuel preferences. These two factors drive multinomial logit models that describe investments in new energy production and consumption capacity. The demand for new capacity is limited by the assumption that capital goods are only replaced at the end of their technical lifetime. The long-term prices that drive the model are determined by resource depletion and technological development. Technological development is determined using learning curves or through exogenous assumptions. Emissions from the energy system are calculated by multiplying energy university of ibadan diploma and production flows by emission factors. A carbon tax can be used to induce a dynamic response, such as an increased use of low- or zero-carbon technologies, energy efficiency improvements and end-of-pipe emission reduction technologies. Negative emissions can be achieved by a combination of the use of bioenergy and carbon capture and storage. FAIR-SiMCaP captures the time- and pathway dependent dynamics of the underlying TIMER model, that are caused by technology learning and inertia related to capital-turnover rates, by scaling the MAC curves based on the reduction effort in university of ibadan diploma previous years. The model limits the MAC curves to 1500 $/tC-eq (409 $/tCO 2 -eq), as the underlying TIMER model provides little additional emission reductions above this value. For non-CO 2 university of ibadan diploma, the MAC curves of Lucas et al (2007) were used. These are based on MAC curves from the EMF21 project (Weyant et al 2006), but made time-dependent to account for technology change and the removal of implementation barriers, while consistency was ensured by using relative reductions rates compared to a university of ibadan diploma emission level. Moreover, the annual reduction in non-CO 2 emissions are assumed to be limited to 2.5%–5% of yearly baseline emissions for most university of ibadan diploma, depending on the source (van Vliet et al 2012). These limits are implemented to model the inertia in non-CO 2 emission reductions and are based on an estimate of the capital turn-over rate and practices in these sectors. The Online Material provides more information on the shape of the MAC curves and implementation of non-CO 2 inertia. The chosen metric colleges and universities in canada FAIR-SiMCaP impacts the substitution across the different gases in a single year as it changes the value of the gas vis-à-vis other case. In the model, this is implemented by scaling the MAC curve of each individual gas using the different conversion factors from tons of a specific greenhouse gas to C-equivalent emissions. A change of metric also affects the optimization over time and may result in different optimal emission pathways. For instance, an increase in the methane GWP value from 21 to 25, makes it more attractive to reduce methane. In this example, the price for reaching university of ibadan diploma certain reduction potential of C-equivalent methane emissions changes by a factor of 21/25. As indicated in the introduction, we have compared the 100 year GWP metric to the time-varying GTP metric and other metrical GWP values. In this paper we use University of ibadan diploma values reported by subsequent IPCC reports. GWPs are based on the integrated radiative forcing over a specific time period of a certain greenhouse gas resulting from a 1 kg pulse emission. IPCC follows a methodology assuming an atmospheric background of constant greenhouse gas free gold money report. Alternatively, GWP values can be calculated assuming a dynamic atmospheric background concentration. These have the advantage that more of the relevant dynamics are captured, but at the cost of introducing an arbitrary element regarding the development of future emissions. For determining GWPs, two important inputs are needed: the specific radiative efficiency of a greenhouse gas and its atmospheric lifetime. GWPs university of ibadan diploma usually expressed relative to the absolute GWP value of CO 2so the ratio of these two numbers results in a dimensionless GWP value. As there are large differences university of ibadan diploma the lifetimes of greenhouse gases, GWPs strongly depend on the time span over which the potential is calculated. To cover this, the IPCC Fourth Assessment Report (AR4) quotes 20, 100 and 500 year time spans. The warming potential of CH how to write a self assessment essay relative to CO 2 is a factor 9 higher with a 20 year time span than with a 500 year time span (see table 1), due to university of ibadan diploma short atmospheric lifetime of CH 4 . Table 1. GWP values and lifetimes for CH 4 and N 2 O used in scenarios, where SAR, TAR and AR4 refer to 100 year GWP values (IPCC 1995, IPCC 2001, IPCC 2007).