Editing IPCC:AR6/SR15/Chapter-1 (section)

==== 1.2.3.2 Pathways temporarily exceeding 1.5°C ====

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With the pathways in this category, also referred to as overshoot pathways, GMST rises above 1.5°C relative to pre-industrial before peaking and returning to 1.5°C around or before 2100 (Figure 1.4, blue lines), subsequently either stabilising or continuing to fall. This allows initially slower or delayed emission reductions, but lowering GMST requires net negative global CO <sub>2</sub> emissions (net anthropogenic removal of CO <sub>2</sub> ; Figure 1.4b). Cooling, or reduced warming, through sustained reductions of net non-CO <sub>2</sub> climate forcing (Cross-Chapter Box 2 in this chapter) is also required, but their role is limited because emissions of most non-CO <sub>2</sub> forcers cannot be reduced to below zero. Hence the feasibility and availability of large-scale CO <sub>2</sub> removal limits the possible rate and magnitude of temperature decline. In this report, overshoot pathways are referred to as 1.5°C pathways, but qualified by the amount of the temperature overshoot, which can have a substantial impact on irreversible climate change impacts (Mathesius et al., 2015; Tokarska and Zickfeld, 2015) <sup>[[#fn:r118|118]]</sup> .

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