Editing IPCC:AR6/SRCCL/Chapter-3 (section)

=== 3.3.2 Changes in surface albedo ===

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Increasing surface albedo in dryland regions will impact the local climate, decreasing surface temperature and precipitation, and provide a positive feedback on the albedo ( ''high confidence'' ) (Charney et al. 1975 <sup>[[#fn:r508|508]]</sup> ). This albedo feedback can occur in desert regions worldwide (Zeng and Yoon 2009 <sup>[[#fn:r509|509]]</sup> ). Similar albedo feedbacks have also been found in regional studies over the Middle East (Zaitchik et al. 2007 <sup>[[#fn:r510|510]]</sup> ), Australia (Evans et al. 2017 <sup>[[#fn:r511|511]]</sup> ; Meng et al. 2014a <sup>[[#fn:r512|512]]</sup> , b <sup>[[#fn:r513|513]]</sup> ), South America (Lee and Berbery 2012 <sup>[[#fn:r514|514]]</sup> ) and the USA (Zaitchik et al. 2013 <sup>[[#fn:r515|515]]</sup> ).

Recent work has also found albedo in dryland regions can be associated with soil surface communities of lichens, mosses and cyanobacteria (Rodriguez-Caballero et al. 2018 <sup>[[#fn:r516|516]]</sup> ). These communities compose the soil crust in these ecosystems and due to the sparse vegetation cover, directly influence the albedo. These communities are sensitive to climate changes, with field experiments indicating albedo changes greater than 30% are possible. Thus, changes in these communities could trigger surface albedo feedback processes ( ''limited evidence, high agreement'' ) (Rutherford et al. 2017 <sup>[[#fn:r517|517]]</sup> ).

A further pertinent feedback relationship exists between changes in land-cover, albedo, carbon stocks and associated GHG emissions, particularly in drylands with low levels of cloud cover. One of the first studies to focus on the subject was Rotenberg and Yakir (2010) <sup>[[#fn:r518|518]]</sup> , who used the concept of ‘radiative forcing’ to compare the relative climatic effect of a change in albedo with a change in atmospheric GHGs due to the presence of forest within drylands. Based on this analysis, it was estimated that the change in surface albedo due to the degradation of semi-arid areas has decreased radiative forcing in these areas by an amount equivalent to approximately 20% of global anthropogenic GHG emissions between 1970 and 2005.

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