Editing IPCC:AR6/SRCCL/Chapter-7 (section)

==== 7.2.3.1 Risk associated with land-based adaptation ====

<div id="section-7-2-3-1-risk-associated-with-land-based-adaptation-block-1"></div>

Land-based adaptation relates to a particular category of adaptation measures relying on land management (Sanz et al. 2017 <sup>[[#fn:r183|183]]</sup> ). While most land-based adaptation options provide co-benefits for climate mitigation and other land challenges (Chapter 6 and Section 6.4.1), in some contexts adaptation measures can have adverse side effects, thus implying a risk to socio-ecological systems.

One example of risk is the possible decrease in farmer income when applying adaptive cropland management measures. For instance, conservation agriculture including the principle of no-till farming, contributes to soil erosion management (Chapter 6 and Section 6.2). Yet, no-till management can reduce crop yields in some regions, and although this effect is minimised when no-till farming is complemented by the other two principles of conservation agriculture (residue retention and crop rotation), this could induce a risk to livelihood in vulnerable smallholder farming systems (Pittelkow et al. 2015 <sup>[[#fn:r184|184]]</sup> ).

Another example is the use of irrigation against water scarcity and drought. During the long lasting drought from 2007–2009 in California, USA, farmers adapted by relying on groundwater withdrawal and caused groundwater depletion at unsustainable levels (Christian-Smith et al. 2015 <sup>[[#fn:r185|185]]</sup> ). The long-term effects of irrigation from groundwater may cause groundwater depletion, land subsidence, aquifer overdraft, and saltwater intrusion (Tularam and Krishna 2009 <sup>[[#fn:r186|186]]</sup> ). Therefore, it is expected to increase the vulnerability of coastal aquifers to climate change due to groundwater usage (Ferguson and Gleeson 2012 <sup>[[#fn:r187|187]]</sup> ). The long-term practice of irrigation from groundwater may cause a severe combination of potential side effects and consequently irreversible results.

<div id="section-7-2-3-2-risk-associated-with-land-based-mitigation"></div>

<span id="risk-associated-with-land-based-mitigation"></span>