Editing IPCC:AR6/WGI/Chapter-4 (section)

===== 4.6.3.3.5 Detectability of climate response to solar radiation modification =====

<div id="h4-18-siblings" class="h4-siblings"></div>

Internal variability could mask the response to solar radiation modification (SRM)-related forcing in the near term ( [[#4.6.3.1|Section 4.6.3.1]] ). A detection of the global scale climate system response to stratospheric sulphate aerosol injection will ''likely'' require a forcing of the size produced by the 1991 Mount Pinatubo eruption ( [[#Robock--2010|Robock et al., 2010]] ). In model simulations of where 5 Tg SO <sub>2</sub> is injected into the stratosphere continuously (roughly one fourth of the 1991 Pinatubo eruption per year) under RCP 4.5, it is shown that, relative to the high-GHG world without SRM, the effect of SRM on global temperature and precipitation is detectable after one to two decades (Bürger and Cubasch, 2015; [[#Lo--2016|Lo et al., 2016]] ) which is similar to the time scale for the emergence of GSAT trends due to strong mitigation ( [[#4.6.3.1|Section 4.6.3.1]] ). The detection time is sensitive to detection methods and filtering techniques ( [[#Lo--2016|Lo et al., 2016]] ). An analysis using GLENS simulation ( [[#MacMartin--2019|MacMartin et al., 2019]] ) compares response in temperature, precipitation, and precipitation minus evapotranspiration (P-E) between a climate state with GHG-induced 1.5°C global mean temperature change and that with the same global mean temperature but under RCP4.5 emissions and a limited deployment of SO <sub>2</sub> injection. It is found that at grid-scale, difference in climate response between these two climate states are not detectable by the end of this century. However, for higher emissions scenarios of the RCP8.5 and correspondingly larger SRM deployment for maintaining the same global mean temperature change of 1.5°C, the regional differences are detectable before the end of the century. In addition to surface temperature and precipitation, observations of aerosol burden and temperature in the stratosphere via the deployment of stratospheric aerosol observing system might facilitate the detection of climate response to SAI.

<div id="4.6.3.3.6" class="h4-container"></div>

<span id="climate-response-to-termination-of-solar-radiation-modification"></span>