Editing IPCC:AR6/SR15/Chapter-2 (section)

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=== Footnotes ===

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<li><span id="fn:1">Kyoto-GHG emissions in this statement are aggregated with GWP-100 values of the IPCC Second Assessment Report.</span></li>
<li><span id="fn:2">Current pledges include those from the United States although they have stated their intention to withdraw in the future.</span></li>
<li><span id="fn:3">In this chapter GWP-100 values from the IPCC Fourth Assessement Report are used because emissions of fluorinated gases in the integrated pathways have been reported in this metric to the database. At a global scale, switching between GWP-100 values of the Second, Fourth or Fifth IPCC Assessment Reports could result in variations in aggregated Kyoto-GHG emissions of about ±5% in 2030 (UNFCCC, 2016)UNFCCC, 2016: ''Aggregate effect of the intended nationally determined contributions: an update'' . FCCC/CP/2016/2, The Secretariat of the United Nations Framework Convention on Climate Change (UNFCCC), Bonn, Germany, 75 pp.</span>

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<li><span id="fn:4">The median and percentiles of the sum of two quantities is in general not equal to the sum of the medians and percentiles, respectively, of the two quantitites,</span></li>
<li><span id="fn:5">Note that aggregated Kyoto-GHG emissions implied by the NDCs from Cross-Chapter Box 11 in Chapter 4 and Kyoto-GHG ranges from the pathway classes in Chapter 2 are only approximately comparable, because this chapter applies GWP-100 values from the IPCC Fourth Assessment Report while the NDC Cross-Chapter Box 11 applies GWP-100 values from the IPCC Second Assessment Report. At a global scale, switching between GWP-100 values of the Second to the Fourth IPCC Assessment Report would result in an increase in estimated aggregated Kyoto-GHG emissions of no more than about 3% in 2030 (UNFCCC, 2016).UNFCCC, 2016: ''Aggregate effect of the intended nationally determined contributions: an update'' . FCCC/CP/2016/2, The Secretariat of the United Nations Framework Convention on Climate Change (UNFCCC), Bonn, Germany, 75 pp.</span>

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<li><span id="fn:6">This section reports ‘direct’ CO <sub>2</sub> emissions as reported for pathways in the database for the report. As shown below, the emissions from electricity are nearly zero around 2050, so the impact of indirect emissions on the whole emission contributions of each sector is very small in 2050.</span></li>
<li><span id="fn:7">Electrification can be linked with the heating and drying process by electric boilers and electro-thermal processes, and also with low-temperature heat demand by heat pumps. In the iron and steel industry, hydrogen produced by electrolysis can be used as a reduction agent of iron instead of coke. Excess resources, such as black liquor, will provide the opportunity to increase the systematic efficiency to use for electricity generation.</span></li>
<li><span id="fn:8">These are first-of-a-kind (FOAK) cost data.</span></li>
<li><span id="fn:9">In this section, we only discuss the direct emissions from the sector, but the selection of building materials has a significant impact on the reduction of energy and emissions during production, such as shift from the steel and concrete to wood-based materials.</span></li>
<li><span id="fn:10">This is estimated for the biofuels produced in a “sustainable manner” from non-food crop feedstocks, which are capable of delivering significant lifecycle GHG emissions savings compared with fossil fuel alternatives, and which do not directly compete with food and feed crops for agricultural land or cause adverse sustainability impacts.</span></li>
<li><span id="fn:11">Land-based mitigation options on the supply and the demand side are assessed in 4.3.2, and CDR options with a land component in 4.3.7. Chapter 5 (Section 5.4) assesses the implications of land-based mitigation for related SDGs, e.g., food security.</span></li>
<li><span id="fn:12">For example, the GLEAM ( http://www.fao.org/gleam/en/ ) model from the UN Food and Agricultural Organisation (FAO).</span></li>
<li><span id="fn:13">Also other metrics to compare emissions have been suggested and adopted by governments nationally (Kandlikar, 1995; Marten et al., 2015; Shindell, 2015; IWG, 2016).Kandlikar, M., 1995: The relative role of trace gas emissions in greenhouse abatement policies. ''Energy Policy'' , '''23(10)''' , 879–883, doi: [https://dx.doi.org/10.1016/0301-4215(95)00108-u 10.1016/0301-4215(95)00108-u] .</span>

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Marten, A.L., E.A. Kopits, C.W. Griffiths, S.C. Newbold, and A. Wolverton, 2015: Incremental CH <sub>4</sub> and N <sub>2</sub> O mitigation benefits consistent with the US Government’s SC-CO <sub>2</sub> estimates. ''Climate Policy'' , '''15(2)''' , 272–298, doi: [https://dx.doi.org/10.1080/14693062.2014.912981 10.1080/14693062.2014.912981] .

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Shindell, D.T., 2015: The social cost of atmospheric release. ''Climatic Change'' , '''130(2)''' , 313–326, doi: [https://dx.doi.org/10.1007/s10584-015-1343-0 10.1007/s10584-015-1343-0] .

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IWG, 2016: ''Technical Support Document: Technical Update of the Social Cost of Carbon for Regulatory Impact Analysis  Under Executive Order 12866'' . Interagency Working Group on Social Cost of Greenhouse Gases, United States, 35 pp.</li>
<li><span id="fn:14">Unlike AR5, which only included cost-effective scenarios for estimating discounted average carbon prices for 2015–2100 (also using a 5% discount rate) (see Clarke et al., 2014, p.450), please note that values shown in Figure 2.26b include delays or technology constraint cases (see Sections 2.1 and 2.3).larke, L. et al., 2014: Assessing transformation pathways. In: ''Climate Change 2014: Mitigation of Climate Change. Contribution of Working Group III to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change'' [Edenhofer, O., R. Pichs-Madruga, Y. Sokona, E. Farahani, S. Kadner, K. Seyboth, A. Adler, I. Baum, S. Brunner, P. Eickemeier, B. Kriemann, J. Savolainen, S. Schlömer, C. von Stechow, T. Zwickel, and J.C. Minx (eds.)]. Cambridge University Press, Cambridge, United Kingdom and New York, NY, USA, pp. 413–510.</span>

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