Editing IPCC:AR6/WGII/Chapter-9 (section)

=== 9.4.3 Cross-sectoral and Transboundary Solutions ===

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Climate change does not present its problems and opportunities conveniently aligned with traditional sectors, so mechanisms are needed to facilitate interactions and collaborations between people working in widely different sectors ( [[#Simpson--2021b|Simpson et al., 2021b]] ). Traditional risk assessments typically only consider one climate hazard and one sector at a time, but this can lead to substantial misestimation of risk because multiple climate risks can interact to cause extreme impacts ( [[#Zscheischler--2018|Zscheischler et al., 2018]] ; [[#Simpson--2021b|Simpson et al., 2021b]] ).

Because multiple risks are interlinked and can cascade and amplify risk across sectors, cross-sectoral approaches that consider these interlinkages are essential for CRD, especially for managing trade-offs and co-benefits among SDGs, mitigation and adaptation responses ( [[#Liu--2018a|Liu et al., 2018a]] ).

In Africa, placing cross-sectoral approaches at the core of CRD provides significant opportunities to deliver large benefits and/or avoided damages across multiple sectors including water, health, ecosystems and economies ( ''very high confidence'' ) (Boxes 9.5; 9.6; 9.7). They can also prevent adaptation or mitigation action in one sector exacerbating risks in other sectors and resulting in maladaptation, for example, from large-scale dam construction or large-scale afforestation (e.g., water–energy–food nexus and large-scale tree planting efforts) (Boxes 9.3; 9.5).

Cross-sectoral or ‘nexus’ approaches can improve the ability of decision makers to foresee and prevent major climate impacts. Barriers to developing nexus approaches arise from rigid sectoral planning, regulatory and implementation procedures, entrenched interests, and power structures and established sectoral communication structures. Opportunities for overcoming these barriers include creating a dedicated home for co-development of nexus risk assessment and solutions, promoting co-leadership of projects by multiple sectors, specific budget allocations for nexus projects, facilitating and coordinating services, compiling useful strategies into toolkits, ameliorating inequitable power relations among participants and measuring progress on nexus approaches through metrics ( [[#Palmer--2016|Palmer et al., 2016]] ; [[#Baron--2017|Baron et al., 2017]] ).

Beyond cross-sectoral collaboration, international cooperation is vital to avert dangerous climate change as its impacts reach beyond the jurisdiction of individual states. International good practice and regional agreements, protocols and policies together recognise that regional integration, cooperative governance and benefit-sharing approaches are cornerstones of effective resource security and climate change responses in Africa ( [[#Jensen--2013|Jensen and Lange, 2013]] ; [[#World%20Bank--2017a|World Bank, 2017a]] ; [[#Dombrowsky--2018|Dombrowsky and Hensengerth, 2018]] ). Natural resource development, particularly governance of shared river basins, exemplifies opportunities for governance responses for African nations that can be cooperative, regionally integrated and climate resilient.

In Africa, climate vulnerability crosses geopolitical divides as regional clusters of fragile and high vulnerability countries exist, emphasising the need for transboundary cooperation ( [[#Birkmann--2021|Birkmann et al., 2021]] ; [[#Buhaug--2021|Buhaug and von Uexkull, 2021]] ). Natural resource security is increasingly reliant on transboundary governance, regional integration and cooperation ( [[#Namara--2017|Namara and Giordano, 2017]] ). There are 60 international or shared river basins on the continent, a function of colonial divides and topography, with some basins shared by four or more countries ( [[#UNECA--2016|UNECA, 2016]] ; [[#Popelka--2020|Popelka and Smith, 2020]] ). Climate changes which result in impact and risk pathways across country boundaries and regions (although with different levels of impact) accelerate the urgency for integrated approaches to manage and benefit from shared resources and promote their security for populations and economies ( [[#Namara--2017|Namara and Giordano, 2017]] ; [[#Frame--2018|Frame et al., 2018]] ; [[#Carter--2021|Carter et al., 2021]] ). At the same time, natural resources such as water generate economic benefits shared across boundaries, such as hydroelectric power generation and regional food security ( [[#Dombrowsky--2018|Dombrowsky and Hensengerth, 2018]] ).

Poor governance, particularly at the transboundary level, can undermine water security and climate change is likely to add new challenges to pre-existing dynamics, emphasising the necessity of formal transboundary arrangements ( [[#Jensen--2013|Jensen and Lange, 2013]] ; [[#UNECA--2016|UNECA, 2016]] ). Further, it can constrain access to critical financial resources at a time when it is needed most. This is particularly the case when climate impact pathways manifest at the transboundary level ( [[#Challinor--2018|Challinor et al., 2018]] ; [[#Simpson--2021b|Simpson et al., 2021b]] ), but where the need to protect sovereign interests can block regionally integrated institutional arrangements that are pivotal for accessing the multilateral climate funds for transboundary climate investments that include resilient infrastructure and greater water benefits across Africa’s shared river basins (Cross-Chapter Box INTEREG in Chapter 16; [[#Carter--2021|Carter et al., 2021]] ).

In response, the African Development Bank is supporting two of the most climate-vulnerable and larger African river basins to leverage GCF and Global Environment Facility (GEF) funds to finance Programmes for Integrated Development and Adaptation to Climate Change (PIDACC). PIDACC finance is approved at the multinational level in the Niger basin which is shared by nine west and central African States ( [[#AfDB--2018c|AfDB, 2018c]] ; [[#GCF--2018a|GCF, 2018a]] ), while a PIDACC proposal is currently under development for the Zambezi basin ( [[#Zambezi%20Watercourse%20Commission--2021|Zambezi Watercourse Commission, 2021]] ).

Stakeholders across Africa are recognising the scale and severity of transboundary risks to water. Such risks are two-fold in nature, arising both from potential impacts due to climate change and from responses to climate change ( [[#Simpson--2021b|Simpson et al., 2021b]] ). This awareness among stakeholders is leading to increasingly progressive approaches to natural resource development that can also reduce risk across boundaries within regions. For example, river basin organisations in Southern Africa such as the Orange-Senqu and the Okavango River Basin Commissions are revising treaties considered to pre-date the interrelated issues of climate change, growing populations and water scarcity ( [[#OKACOM--2020|OKACOM, 2020]] ). In parts of west Africa, where climate change is characterised by reduction of precipitation ( [[#Barry--2018|Barry et al., 2018]] ), regionally integrated and climate-resilient economic investments for water resource development are enabled by the Senegal River Basin Organisation (OMVS) which emphasises programme and project development, financing and implementation in ensuing work plans ( [[#World%20Bank--2020e|World Bank, 2020e]] ), as does the Nile Basin Initiative (NBI) in north and east Africa ( [[#Schmeier--2017|Schmeier, 2017]] ; [[#Blumstein--2021|Blumstein and Petersen-Perlman, 2021]] ).

Enhanced transboundary governance arrangements suggest that countries are joining forces to coherently manage and protect natural resources ( [[#Spalding-Fecher--2014|Spalding-Fecher et al., 2014]] ; [[#AfDB--2021|AfDB, 2021]] ). Underlying governance issues and political economy interests block or advance such transitions to regionally integrated resource management and benefit-sharing, the market drivers of water security ( [[#AMCOW--2012|AMCOW, 2012]] ; [[#Soliev--2015|Soliev et al., 2015]] ). Angola, for example, outlines regional adaptation as a priority and one of its unconditional adaptation strategies (which is already funded) is enhancing resilience in the Benguela fisheries system, a project shared with Namibia and South Africa ( [[#GEF%20and%20FAO--2021|GEF and FAO, 2021]] ). Another example is The Great Green Wall for the Sahara and Sahel Initiative, which was launched in 2007 with the aim of tackling land degradation in Africa ( [[#UNCCD--2020|UNCCD, 2020]] ). This transboundary project, led by the African Union Commission, is being implemented in more than 20 countries across Africa’s Sahel region, in cooperation with international partners including UNCCD, GEF and the World Bank. Approximately USD 10 billion have been mobilised and/or promised for this initiative ( [[#UNCCD--2020|UNCCD, 2020]] ). Such statements demonstrate the increasing identification of transboundary risks and approaches to manage and adapt to them as areas of ‘common concern’ that require cooperative adaptation actions. Accelerating strengthened transboundary water and climate governance needs to integrate these climate drivers of compromised water security. The role of institutions such as OMVS and the NBI have demonstrated they can influence economic behaviour among riparian countries of shared river basins highlighting that institutions are an integral part of climate governance in evolving economic systems ( [[#Hodgson--2000|Hodgson, 2000]] ).

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