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

=== 9.9.5 Adaptation in Human Settlements and for Infrastructure ===

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==== 9.9.5.1 Solutions and Residual Risk Observed in Human Settlements ====

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Autonomous responses to climate impacts in 40 African cities show that excess rainfall is the primary climate driver of adaptation, followed by multi-hazard impacts, with 72% of responses focused on excess rainfall ( [[#Hunter--2020|Hunter et al., 2020]] ). Innovation for adaptation in areas such as home design, social networks, organisations and infrastructure, is evident ( [[#Swanepoel--2019|Swanepoel and Sauka, 2019]] ). Social learning platforms also increase communities’ adaptive capacities and resilience to risk ( [[#Thorn--2015|Thorn et al., 2015]] ).

There is limited evidence of successful, proactively planned climate change adaptation in African cities ( [[#Simon--2015|Simon and Leck, 2015]] ), particularly for those countries highly vulnerable to climate change ( [[#Ford--2014|Ford et al., 2014]] ). Planned adaptation initiatives in African cities since 2006 have been predominantly determined at the national level with negligible participation of lower levels of government ( [[#Ford--2014|Ford et al., 2014]] ). Adaptation action directed at vulnerable populations is also rare ( [[#Ford--2014|Ford et al., 2014]] ). There are emerging examples of cities planned climate adaptation measures, such as those advanced by Durban ( [[#Roberts--2010|Roberts, 2010]] ), Cape Town ( [[#Taylor--2016|Taylor et al., 2016]] ) and Lagos ( [[#Adelekan--2016|Adelekan, 2016]] ). There are also examples of community-led projects such as those in Maputo ( [[#Broto--2015|Broto et al., 2015]] ), which have seen meaningful help from a range of policy networks, dialogue forums and urban learning labs ( [[#Pasquini--2014|Pasquini and Cowling, 2014]] ; [[#Shackleton--2015|Shackleton et al., 2015]] ). These researched cities can be lighthouses for wider exchange and the basis for a deeper synthesis of evidence ( [[#Lindley--2019|Lindley et al., 2019]] ). However, planned adaptation progress is slow, especially in west and central Africa ( [[#Tiepolo--2014|Tiepolo, 2014]] ).

Ecosystem-based approaches are also being deployed in mitigating and adapting to climate change, with demonstrated long-term health, ecological and social co-benefits ( [[#9.6.4|Section 9.6.4]] ; [[#Swanepoel--2019|Swanepoel and Sauka, 2019]] ). The cost–benefit analysis of nature-based solutions, compared to purely grey infrastructure initiatives, is discussed in [[IPCC:Wg2:Chapter:Chapter-6|Chapter 6]] ( [[IPCC:Wg2:Chapter:Chapter-6#6.3.3|Section 6.3.3]] ). Nature-based solutions can also lengthen the life of existing built infrastructure ( [[#du%20Toit--2018|du Toit et al., 2018]] ). Since 2014, an increasing number of EbA projects involving the restoration of mangrove, wetland and riparian ecosystems have been initiated across Africa, a majority of which address water-related climate risks (Table 9.9).

'''Table 9.9 |''' Examples of ecosystem-based adaptations to climate impacts in African cities.

{| class="wikitable"
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! Project

! City

! Ecosystem-based Adaptation

! Reference

|-
| Green Urban Infrastructure

| Beira (Mozambique)

| Mitigating against increased flood risks through restoration of mangrove and other natural habitats along the Chiveve river and the development of urban green spaces.

| [[#IPCC--2019a|IPCC (2019a)]] ; [[#CES%20Consulting%20Engineers%20Salzgitter%20GmbH%20and%20Inros%20Lackner%20SE--2020|CES Consulting Engineers Salzgitter GmbH and Inros Lackner SE (2020)]]

|-
| The Msimbazi Opportunity Plan (MOP) 2019–2024

| Dar es Salaam, Tanzania

| Enhancing urban resilience to flood risk by reducing flood hazard, and reducing people, properties and critical infrastructure exposed to flood hazard.

| Croitoru et al. (2019)

|-
| Tanzania Ecosystem-based Adaptation

| Dar es Salaam and five coastal districts, Tanzania

| Rehabilitation of over 3000 ha of climate-resilient mangrove species.

| [[#UNEP--2019|UNEP (2019)]]

|-
| Building Resilience in the Coastal Zone through Ecosystem-based Approaches to Adaptation

| Maputo, Mozambique

| Restoration of mangrove and riparian ecosystems for flood control and protection from coastal flooding enhanced water supply.

| [[#GEF--2019|GEF (2019)]]

|-
| Addressing Urgent Coastal Adaptation Needs and Capacity Gaps in Angola

| Five coastal communities in Angola

| Restoration of 561 ha of wetland, mangroves and other ecological habitats to promote flood defence and mitigate the threat of drought.

| [[#UNEP--2020|UNEP (2020)]]

|-
| Green City Kigali

2016

| Kigali, Rwanda

| Planned neighbourhood of 600 ha, integrating green building and design, efficient and renewable energy, recycling and inclusive living.

| [[#SWECO--2019|SWECO (2019)]]

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| Urban Natural Assets for Africa—Rivers for Life

| Kampala, Uganda

| Preservation of natural buffers to enhance the protective functions offered by natural ecosystems that support disaster resilience benefit.

| [[#World%20Bank--2015|World Bank (2015)]]

|}

For green infrastructure to be successful, however, sustainable landscapes and regions require both stewardship and management at multiple levels of governance and social scales ( [[#Brink--2016|Brink et al., 2016]] ).

Currently, planned climate change adaptation to coastal hazards in Africa’s large coastal cities has mainly been achieved through expensive coastal engineering efforts such as sea walls, revetments, breakwaters, spillways, dikes and groynes. Examples are found in west Africa ( [[#Adelekan--2016|Adelekan, 2016]] ; [[#Alves--2020|Alves et al., 2020]] ). Beach nourishment efforts have also been undertaken in Egypt, Banjul and Lagos ( [[#Frihy--2016|Frihy et al., 2016]] ; [[#Alves--2020|Alves et al., 2020]] ). However, the use of vegetated coastal ecosystems presents greater opportunities for African cities because of the lower costs ( [[#Duarte--2013|Duarte et al., 2013]] ).

Most (&gt;80%) of Africa’s large coastal cities have no adaptation policies and, where available, these are mostly, except for South Africa, dominated by national plans ( [[#Olazabal--2019|Olazabal et al., 2019]] ). Coastal adaptation actions minimally consider socioeconomic projections and are not at all aligned with future climate scenarios and risks, which is highly limiting for adaptation planning ( [[#Olazabal--2019|Olazabal et al., 2019]] ).

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==== 9.9.5.2 Anticipated Adaptation and Residual Risk for Human Settlements ====

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Africa’s smaller towns and cities have received far less scholarly and policy development attention for adaptation ( [[#Clapp--2017|Clapp and Pillay, 2017]] ; [[#White--2019|White and Wahba, 2019]] ). Smaller towns also have less ability to partner effectively with private entities for adaptation initiatives ( [[#Wisner--2015|Wisner et al., 2015]] ). Political will to address climate change and information flows between key stakeholders, professional and political decision makers may be easier to establish in smaller cities than in the megacity context ( [[#Wisner--2015|Wisner et al., 2015]] ).

Exposure and vulnerability are particularly acute in informal areas, making coordinated adaptation challenging. Yet, there is growing recognition of the potential for bottom-up adaptation that embraces informality in order to more effectively reduce risk (Figure 9.31; [[#Taylor--2021a|Taylor et al., 2021a]] ). This can provide an opportunity for change towards more risk-sensitive urban development and transformative climate adaptation ( [[#Leck--2018|Leck et al., 2018]] ). Addressing social vulnerability is particularly important for ensuring the resilience of populations at risk. Improved monitoring, modelling and communication of climate risks is needed to reduce the impacts of climate hazards ( [[#Tramblay--2020|Tramblay et al., 2020]] ; [[#Cole--2021a|Cole et al., 2021a]] ).

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[[File:a9afeb3beb4a5f690865789d2c2e6514 IPCC_AR6_WGII_Figure_9_031.png]]

'''Figure 9.31 |''' '''Key elements of adaptation in informal settlements in Africa.''' Adapted from Thorn et al. (2015); [[#Fedele--2019|Fedele et al. (2019)]] ; [[#Satterthwaite--2020|Satterthwaite et al. (2020)]] .

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==== 9.9.5.3 Anticipated Adaptation for Transport Systems in Africa ====

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Higher costs will be incurred to maintain and repair damages caused to existing roads as a result of climate change for countries with no adaptation policy for transport infrastructure ( ''very high confidence'' ) ( [[#Chinowsky--2013|Chinowsky et al., 2013]] ; [[#Cervigni--2017|Cervigni et al., 2017]] ; [[#Koks--2019|Koks et al., 2019]] ). Countries with a greater percentage of unpaved roads will, however, incur higher economic costs through adaptation policy when compared to no adaptation policy ( [[#Cervigni--2017|Cervigni et al., 2017]] ).

Adaptation measures in the transport sector have focused on the climate resilience of road infrastructure. Modelling suggests that proactive adaptation of road designs to account for temperature increases is a ‘no regret’ option in all cases, but accounting for precipitation increases should be assessed on a case-by-case basis ( ''medium confidence'' ) ( [[#Cervigni--2017|Cervigni et al., 2017]] ). African governments will need climate adaptation financing options to meet the higher capital requirements of resilient road infrastructure interventions ( [[#Hearn--2016|Hearn, 2016]] ).

Under the Nationally Appropriate Mitigation Action programme, investments in public transport and transit-oriented development are highlighted as desired mitigation–adaptation interventions within cities of South Africa, Ethiopia and Burkina Faso (UNFCCC, 2020). These interventions simultaneously reduce the vulnerability of low-income residents to climate shocks, prevent lock-ins into carbon-intensive development pathways and reduce poverty ( ''high confidence'' ) ( [[#Hallegatte--2016|Hallegatte et al., 2016]] ; [[#Rozenberg--2019|Rozenberg et al., 2019]] ). The combined mitigation–adaptation interventions in the land use transport systems of African cities are also expected to have sufficient short-term co-benefits (reducing air pollution, congestion and traffic fatalities) to be ‘no regret’ investments ( ''very high confidence'' ) ( [[#Hallegatte--2016|Hallegatte et al., 2016]] ; [[#Rozenberg--2019|Rozenberg et al., 2019]] ). Only eight African countries have transport-specific adaptation measures in their NDCs ( [[#Nwamarah--2018|Nwamarah, 2018]] ). Five African countries have submitted NAPs (Table 9.10).

'''Table 9.10 |''' Transport sector references in the National Adaptation Plans (NAPs) of five African countries. Source: [[#Government%20of%20Burkina%20Faso--2015|Government of Burkina Faso (2015)]] ; [[#Government%20of%20Cameroon--2015|Government of Cameroon (2015)]] ; [[#Government%20of%20Togo--2016|Government of Togo (2016)]] ; [[#Government%20of%20Kenya--2017|Government of Kenya (2017)]] ; [[#Government%20of%20Ethiopia--2019|Government of Ethiopia (2019)]] .

{| class="wikitable"
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! rowspan="2"| Country

! rowspan="2"| Identify climate change impacts

! rowspan="2"| Promote transport as a disaster risk reduction measure

! colspan="4"| Transport-specific adaptation measures

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! Climate-resilient design standards

! Promote public transport

! Promote non-motorised transport

! Urban land use planning

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| Burkina Faso

| X

|
| X

| X

|
| X

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| Cameroon

|
| X

| X

|
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| Ethiopia

| X

| X

| X

| X

|
|-
| Kenya

| X

|
|-
| Togo

|
| X

| X

|
|}

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==== 9.9.5.4 Projected Adaptation for Electricity Generation and Transmission in Africa ====

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Most electricity infrastructure in Africa has been designed to account for historical climatic patterns. Failure to consider future climate scenarios in power system planning increases the climate risk facing infrastructure and supplies. Yet, energy demand for cooling over Africa, for example, is expected to increase, with a potential increase in heat stress, population growth and rapid urbanisation to 1.2% of total final energy demand by 2100 compared to 0.4% in 2005 ( [[#Parkes--2019|Parkes et al., 2019]] ). Integrated energy system costs from increased demand for cooling to mitigate heat stress are projected to accumulate from 2005 to USD 51.3 billion by 2035 at 2°C and to USD 486.5 billion by 2076 at 4°C global warming ( [[#Parkes--2019|Parkes et al., 2019]] ).

For hydropower, adaptations to different climate conditions can be made at the level of the power plant, turbine size and reservoir storage capacities, and can be adjusted to projected hydrological patterns ( [[#Lempert--2015|Lempert et al., 2015]] ). At the river basin level, integrated water resource management practices can be implemented across sectors that compete for the same water resources ( [[#Howells--2013|Howells et al., 2013]] ). At the power system level, the energy mix and the protocol through which different power plants are dispatched can be adapted to different climate scenarios ( [[#Spalding-Fecher--2017|Spalding-Fecher et al., 2017]] ; [[#Sridharan--2019|Sridharan et al., 2019]] ).

Given the uncertainty around future hydroclimate conditions, hydropower development decisions carry risk of ‘regrets’ (that is, damages or missed opportunities) when a different climate than was expected materialises. ‘Robust adaptation’ refers to an adaptation strategy that balances risks across different climate scenarios (Cross-Chapter Box DEEP in Chapter 17; [[#Cervigni--2015|Cervigni et al., 2015]] ). Development bank lending principles require consideration of the regional picture and interactions with other developments along a river when they determine the social and environmental impacts of the proposed hydropower project. However, these principles often do not explicitly consider climate change, so the risk of recurring drought-induced hydropower shortages could be missed (Box 9.5).

Lastly, given the degree to which hydropower competes with other sectors and ecosystems for the same water resources, it is critical that hydropower planning and adaptation does not occur in isolation. As discussed in [[#9.7|Section 9.7]] , it must be part of an integrated water management system that balances the needs of different water-reliant sectors with other societal and ecological demands under increasingly variable climate and hydrological conditions ( [[#9.7.3|Section 9.7.3]] ).

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