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Global Futures Report 2013 - Box 2

16 All energy scenarios portray a mixture of energy supply technolo- gies combined with energy demand growth and energy efficiency improvements. For example, ExxonMobil (2012) shows 77% fossil fuels, 15% renewables, and 8% nuclear by 2040. The IEA ETP (2012) “2DS” case shows 46% fossil fuels, 41% renewables, and 12% nuclear by 2050. And Greenpeace (2012) shows 18% fossil fuels, 82% renewables, and no nuclear by 2050. (For elaboration of information in this box, see Annex 3 and its references.) Many scenarios that portray carbon mitigation objectives or results (see below) also split out fossil fuels into sub-shares for fossil fuels with carbon capture and storage (CCS). For example, in the GEA (2012) “Supply” case, all coal power plants and some natural gas plants have CCS by 2050. The degree of energy efficiency improvements and energy- demand reductions deemed possible and projected into the future is a key determinant of the absolute amounts of renew- ables and the shares attained in scenarios. As many scenarios note, if total energy demand in the future is reduced substantially, relative to what it otherwise would be (i.e., a baseline or refer- ence case), then it is easier to meet that reduced demand with higher shares of renewables. For example, the IEA WEO (2012) “450” case shows 21% less energy demand in 2035 than the reference case. Similarly, IEA ETP (2012) “2DS” shows 26% less energy demand in 2050 compared to a reference case, and the GEA (2012) “Efficiency” case shows 33% less energy demand by 2050 compared to a supply-intensive case. For scenarios with high levels of energy efficiency, the absolute increase in renewable energy can be modest and still provide high future shares of renewables. For example, Greenpeace, in projecting 40% less energy demand in 2050 due to energy efficiency (relative to a 2050 reference case), shows that global energy demand in 2050 is just about the same as energy demand today. And according to Greenpeace, achieving an 82% share of renewables in that situation only means a 6-fold increase in the absolute amount of renewable energy between now and 2050. In contrast, both IEA WEO (2012) “450” and BP (2012) scenarios show a roughly 2.3-fold increase in the absolute amount of renewables by 2030–2035, but they show much lower renewable energy shares—15% for BP and 27% for IEA—due to much lower levels of energy efficiency improvements. And some of the 160 scenarios surveyed by IPCC (2011) show more than a 6-fold increase in absolute renewables by 2050 but still a lower share than Greenpeace. Carbonmitigationmotivationsareanexplicitdriverorgoalofmany published scenarios. Such scenarios are typically called “carbon- constrained” or “back-casts,” which means they work backward from some defined future goal or constraint, such as stabiliza- tion of annual carbon emissions at a given level, or stabilization of atmospheric concentration of greenhouse gases. Scenarios then project what mix of energy technologies and what energy system characteristics will meet the chosen constraint, within the bounds of economic competitiveness and technological feasibility. Carbon-constrained scenarios typically show trade-offs between renewables, energy efficiency, nuclear power, and CCS technolo- gies for fossil fuel plants in achieving carbon reduction goals. The IPCC (2011) surveyed over 160 climate-mitigation scenarios with climate goals by 2100, organized into ranges based on the stabilized atmospheric concentration of CO2: one range higher than 600 parts per million (ppm), three ranges 400–600 ppm, and one range below 400 ppm. Renewable shares were above 50% for a majority of scenarios around 450 ppm, and up to 77% for some lower concentrations. Other examples of carbon goals or constraints in global scenarios include IEA RETD (2010), which is based on stabilization at 400 ppm by 2100 and shows a 56% share of renewables, and IEA WEO (2012), which is based on 450 ppm and shows a 27% share of renewables (along with nuclear and CCS). Other scenarios tar- get emissions reductions rather than stabilization levels, such as Greenpeace (2012), which results in 85% lower energy-related CO2 emissions by 2050 (relative to 1990 base year), and the range of GEA (2012) scenarios, which result in 30–70% lower emissions by 2050 (relative to 2000 base year). For more on scenarios and variables that affect renewable energy futures, see Annex 3. Source: See Endnote 7 for this chapter. Box 2 | Renewable Energy in Global Energy and Climate Scenarios RENEWABLES GLOBAL FUTURES REPORT 01 how much renewables? to 2040 (2012) both show an under-15% share by 2030–2040. The EIA (2011) shows 14% by 2035, and the IEA’s World Energy Outlook (WEO, 2012), in its “New Policies” scenario, shows 18% by 2035. Conservative viewpoints by oil and gas companies mirror such conservative scenarios. These companies continue to make state- ments such as “fossil fuels will continue to provide the majority of the world’s energy supplies for decades to come” (Chevron), and “oil’s preeminence in the global energy mix will remain unchallenged in the foreseeable future” (Total).6 Moderate scenarios show long-term renewable energy shares in the 25–40% range. Two IEA examples are the IEA WEO (2012) “450” carbon-stabilization scenario, which shows a 27% renewable energy share by 2035, and the IEA ETP (2012) “2DS” scenario, which shows a 41% share by 2050. The IPCC Special Report on Renewable Energy (2011) synthesized the results of over 160 climate-mitigation sce- narios (most from 2009–2010) and found that over half of them project shares above 27% by 2050—a large group in the “moderate” category.7 (And many show very high absolute amounts of renew- ables, too, under high global energy demand scenarios; see Box 2.) High-renewables scenarios project 50–95% energy shares of renewables by 2050. For example, the GEA Global Energy Assessment (2012) shows up to 75% in the highest of its “Efficiency” cases and a median share of 55%. The “ACES” scenario by the IEA multilateral program Renewable Energy Technology Deployment (2010) shows 55%. And among the group of 160 scenarios surveyed by the IPCC (2011), there are a number in the range of 50–80%. The biennial

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