Based on this information, we assume that bioenergy production of less than 8.7 Gtoe causes
no major change of land use and no additional CO2 emission.4 Fig. 3 Comparison of global bioenergy supply potential in 2050. Source: Fisher and Schrattenholzer (2001), Hoogwijk et al. (2003, 2005), Smeets et al. (2004, 2007), Berndes et al. (2003), Haberl et al. (2007) For nuclear energy, we GSK126 develop a scenario for future nuclear power capacity expansion based on existing government plans and use it for all model runs. The scenario includes new construction of nuclear power plants already under construction and nuclear power plants already planned or proposed. Information on the new construction of nuclear power plants is taken from the World Nuclear Association (http://www.world-nuclear.org/info/reactors.html). In this scenario, the global total nuclear power plant capacity increases from 364 GW in 2005 to 846 GW in 2050.5 For CCS, we assume a worldwide CO2 CB-839 in vivo storage capacity of about 4,600 GtCO2. This is a median of the estimated values in various studies (Dooley et al. 2006; Hendriks
et al. 2004; IEA 2008, 2010). Further, we assume the maximum annual storage rate based on an ambitious growth pathway in IEA (2010). In this scenario, the maximum annual CO2 storage worldwide in 2050 is about 10 GtCO2. GHG price paths To understand the relationship between GHG emission reduction and the
emission reduction cost, we perform multiple model runs with Angiogenesis inhibitor different GHG price paths and compare the resulting emissions. Figure 4 shows 13 GHG price path scenarios run through the model. Fig. 4 GHG price path scenarios The scenario names are based on the GHG price in 2050 (in the s800 scenario, for example, the GHG price in 2050 is $800/tCO2-eq). In all of the scenarios except the s0 scenario, the GHG price starts from $0/tCO2-eq in 2010 and increases linearly up to 2050 (the price in the s0 scenario stays at zero). The plot therefore shows, for example, a GHG price of $200/tCO2-eq in the year 2020 in s800 scenario. Reference scenario The s0 scenario can be regarded as the ‘no climate policy’ case, as it lacks any incentive to reduce GHG emissions specifically for climate mitigation. Accordingly, we TCL use the s0 scenario as the basis for emission reduction. For convenience, we refer to the s0 scenario as the ‘reference scenario’ in the sections to follow. Global GHG emissions in the reference scenario reach 52 GtCO2-eq in 2020 and 70 GtCO2-eq in 2050. These levels correspond to a 37 and 85 % increase relative to the 1990 level, respectively (Fig. 5). GHG emissions increase more rapidly in non-Annex I regions than in Annex I regions: the average growth rate for GHG emissions from 1990 to 2050 in the former is 1.5 %/year, while that in the latter is only 0.3 %/year.