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

===== 3.6.3.2.1 Area-based protection: MPAs for adapting to climate change =====

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Marine protected areas are the most widely implemented area-based management approach ( [[#3.6.2.3|Section 3.6.2.3.2]] ), commonly intended to conserve, preserve or restore biodiversity and habitats, protect species or manage resources (especially fisheries) ( [[#National%20Research%20Council--2001|National Research Council, 2001]] ). By August 2021, 7.74% of the ocean was protected (in both MPAs and OECMs) ( [[#UNEP-WCMC%20and%20IUCN--2021|UNEP-WCMC and IUCN, 2021]] ), primarily within nations’ exclusive economic zones (EEZs). These MPAs support adaptation by sustaining nearshore ecosystems that provide natural erosion barriers (Sections 3.4.2.1–3.4.2.5; Cross-Chapter Box SLR in Chapter 3), ecosystem function ( [[#Cheng--2019|Cheng et al., 2019]] ), habitat, natural filtration, carbon storage, livelihoods and cultural opportunities (Sections 3.5.5, 3.5.6; [[#Erskine--2021|Erskine et al., 2021]] ), and help ecosystems and livelihoods recover after extreme events ( [[#Roberts--2017|Roberts et al., 2017]] ; [[#Aalto--2019|Aalto et al., 2019]] ; [[#Wilson--2020a|Wilson et al., 2020a]] ). However, in 2021 only 2.7% of the ocean was in fully or highly protected MPAs ( [[#Marine%20Conservation%20Institute--2021|Marine Conservation Institute, 2021]] ), the hard-to-achieve states that most effectively rebuild biomass and fish community structure ( [[#Sala--2017|Sala and Giakoumi, 2017]] ; [[#Bergseth--2018|Bergseth, 2018]] ; [[#Zupan--2018|Zupan et al., 2018]] ; [[#Ohayon--2021|Ohayon et al., 2021]] ). Only 1.18% of ABNJ is protected ( [[#UNEP-WCMC%20and%20IUCN--2021|UNEP-WCMC and IUCN, 2021]] ), mostly due to governance limitations ( [[#O’Leary--2017|O’Leary and Roberts, 2017]] ; [[#Vijayaraghavan--2021|Vijayaraghavan, 2021]] ), but calls to protect more ABNJ emphasise the need to protect the habitats of long-range pelagic fish and marine mammals, maintain the ocean’s regulating functions and minimise impacts from uses such as maritime shipping or deep-sea mining (Table 3.30).

Marine protected areas are theorised to facilitate ecological climate adaptation and contribute to SDG14 (Life Below Water) (Table 3.30; Figure 3.26; [[#Bates--2014|Bates et al., 2014]] ; [[#Lubchenco--2015|Lubchenco and Grorud-Colvert, 2015]] ; [[#Gattuso--2018|Gattuso et al., 2018]] ) because they alleviate non-climate drivers and promote biodiversity (i.e., ‘managed resilience hypothesis’) ( [[#Bruno--2019|Bruno et al., 2019]] ; [[#Maestro--2019|Maestro et al., 2019]] ; [[#Cinner--2020|Cinner et al., 2020]] ). Current MPAs offer conservation benefits such as increases in biomass and diversity of habitats, populations and communities ( ''high confidence'' ) ( [[#Pendleton--2018|Pendleton et al., 2018]] ; [[#Bates--2019|Bates et al., 2019]] ; [[#Stevenson--2020|Stevenson et al., 2020]] ; [[#Lenihan--2021|Lenihan et al., 2021]] ; [[#Ohayon--2021|Ohayon et al., 2021]] ), and these benefits may last after some (possibly climate-enhanced) disturbances (e.g., tropical cyclones) ( [[#McClure--2020|McClure et al., 2020]] ). But current MPAs do not provide resilience against observed warming and heatwaves in tropical-to-temperate ecosystems ( ''medium confidence'' ) ( [[#Bates--2019|Bates et al., 2019]] ; [[#Bruno--2019|Bruno et al., 2019]] ; [[#Freedman--2020|Freedman et al., 2020]] ; [[#Graham--2020|Graham et al., 2020]] ; [[#Rilov--2020|Rilov et al., 2020]] ). There is ''robust evidence'' that processes around MPA design and implementation strongly influence whether outcomes are beneficial or harmful for adjacent human communities (Mc [[#Neill--2018|Neill et al., 2018]] ; [[#Zupan--2018|Zupan et al., 2018]] ; [[#Ban--2019|Ban et al., 2019]] ).

Current placement and extent of MPAs will not provide substantial protections against projected climate change past 2050 ( ''high confidence'' ), as the placement of MPAs has been driven more often by political expediency (e.g., [[#Leenhardt--2013|Leenhardt et al., 2013]] ) than by managing key drivers of biodiversity loss ( [[#Cockerell--2020|Cockerell et al., 2020]] ; [[#Stevenson--2020|Stevenson et al., 2020]] ) or climate-induced drivers ( [[#Bruno--2018|Bruno et al., 2018]] ). Only 3.5% of the area currently protected will provide refuges from both SST and deoxygenation by 2050 under both RCP4.5 and RCP8.5 ( [[#Bruno--2018|Bruno et al., 2018]] ), and MPAs are more exposed to climate change under RCP8.5 than non-MPAs ( [[#3.4.3.3.4|Section 3.4.3.3.4]] ; Figure 3.20d). Community thermal tolerances will be exceeded by 2050 in the tropics and by 2150 for many higher-latitude MPAs ( [[#Bruno--2018|Bruno et al., 2018]] ). Most MPA design has focused on the surface ocean, but MPAs are assumed to protect the entire water column and benthos. Climate-induced drivers ( [[#3.2|Section 3.2]] ) throughout the water column and rapidly accelerating climate velocities at depths below 200 m ( [[#Johnson--2018|Johnson et al., 2018]] ; [[#Brito-Morales--2020|Brito-Morales et al., 2020]] ) are projected to affect virtually all North Atlantic deep-water and open-ocean area-based management zones in the next 20–50 years ( [[#Johnson--2018|Johnson et al., 2018]] ), and the conservation goals of benthic MPAs in the North Sea are not expected to be fulfilled ( [[#Weinert--2021|Weinert et al., 2021]] ). Heightened risk of non-indigenous species immigration from vessel traffic plus climate change further endangers MPA success ( [[#Iacarella--2020|Iacarella et al., 2020]] ), a particular concern in the Mediterranean ( [[#D’Amen--2020|D’Amen and Azzurro, 2020]] ; [[#Mannino--2021|Mannino and Balistreri, 2021]] ), where the current MPA network is already highly vulnerable to climate change ( [[#Kyprioti--2021|Kyprioti et al., 2021]] ). This new evidence supports SROCC’s ''high confidence'' assessment that present governance arrangements, including MPAs, are too fragmented to provide integrated responses to the increasing and cascading risks from climate change in the ocean (SROCC SPMC1.2; [[#IPCC--2019c|IPCC, 2019c]] ).

Strategic conservation planning can yield future MPA networks substantially more ready for climate change (e.g., [[#3.6.3.1.5|Section 3.6.3.1.5]] ; SROCC SPM C2.1; [[#IPCC--2019c|IPCC, 2019c]] ; [[#Frazão%20Santos--2020|Frazão Santos et al., 2020]] ; [[#Rassweiler--2020|Rassweiler et al., 2020]] ). Global protection is increasing ( [[#Worm--2017|Worm, 2017]] ; [[#Claudet--2020b|Claudet et al., 2020b]] ) as nations pursue international targets (e.g., SDG14, Life Below Water aimed to conserve 10% of the ocean by 2020), and the UN CBD proposes to protect 30% by 2030 ( [[#3.6.4|Section 3.6.4]] ; SM3.5.3; [[#CBD--2020|CBD, 2020]] ). A growing body of evidence ( [[#Tittensor--2019|Tittensor et al., 2019]] ; [[#Zhao--2020a|Zhao et al., 2020a]] ; [[#Pörtner--2021b|Pörtner et al., 2021b]] ; [[#Sala--2021|Sala et al., 2021]] ) underscores the urgent need to pursue biodiversity, ecosystem-service provision and climate-adaptation goals simultaneously, while acknowledging inherent trade-offs ( [[#Claudet--2020a|Claudet et al., 2020a]] ; [[#Sala--2021|Sala et al., 2021]] ). Frameworks to create ‘climate-smart’ MPAs ( [[#Tittensor--2019|Tittensor et al., 2019]] ) generally include: (a) defining conservation goals that embrace resource vulnerabilities and co-occurring hazards; (b) carefully selecting adaptation strategies that include IKLK while respecting Indigenous rights and accommodating human behaviour ( [[#Kikiloi--2017|Kikiloi et al., 2017]] ; [[#Thomas--2018|Thomas, 2018]] ; [[#Yates--2019|Yates et al., 2019]] ; [[#Failler--2020|Failler et al., 2020]] ; [[#Wilson--2020a|Wilson et al., 2020a]] ; [[#Croke--2021|Croke, 2021]] ; Reimer et al., 2021; [[#Vijayaraghavan--2021|Vijayaraghavan, 2021]] ); (c) developing protection that is appropriate for all ocean depths ( [[#Brito-Morales--2018|Brito-Morales et al., 2018]] ; [[#Frazão%20Santos--2020|Frazão Santos et al., 2020]] ; [[#Wilson--2020a|Wilson et al., 2020a]] ), especially considering climate velocity ( [[#Arafeh-Dalmau--2021|Arafeh-Dalmau et al., 2021]] ); (d) using dynamic national and international management tools to accommodate extreme events or species distribution shifts ( [[#Gaines--2018|Gaines et al., 2018]] ; [[#Pinsky--2018|Pinsky et al., 2018]] ; [[#Bindoff--2019a|Bindoff et al., 2019a]] ; [[#Scheffers--2019|Scheffers and Pecl, 2019]] ; [[#Tittensor--2019|Tittensor et al., 2019]] ; [[#Cashion--2020|Cashion et al., 2020]] ; [[#Crespo--2020|Crespo et al., 2020]] ; [[#Frazão%20Santos--2020|Frazão Santos et al., 2020]] ; [[#Maxwell--2020b|Maxwell et al., 2020b]] ), which could build on dynamic regulations already in place for fishing or ship strikes ( [[#Maxwell--2020b|Maxwell et al., 2020b]] ); and (e) seeking to increase connectivity ( [[#Wilson--2020a|Wilson et al., 2020a]] ), using genomic or multi-species model insights ( [[#Xuereb--2020|Xuereb et al., 2020]] ; [[#Friesen--2021|Friesen et al., 2021]] ; [[#Lima--2021|Lima et al., 2021]] ).

There is growing international support for a 30% conservation target for 2030 ( [[#Gurney--2021|Gurney et al., 2021]] ), which will need efforts beyond protected areas. For example, OECMs recognise management interventions that sustain biodiversity, irrespective of their main objective ( [[#Maxwell--2020b|Maxwell et al., 2020b]] ; [[#Gurney--2021|Gurney et al., 2021]] ). There is ''high agreement'' on the potential of OECMs to contribute to conservation and equity, for example, by recognising Indigenous territories as OECMs ( [[#Maxwell--2020b|Maxwell et al., 2020b]] ; [[#Gurney--2021|Gurney et al., 2021]] ); however, the capacity of these conservation tools to provide adaptation outcomes remains unexplored.

In summary, MPAs and other marine spatial-planning tools have great potential to address climate-change mitigation and adaptation in ocean and coastal ecosystems, if they are designed and implemented in a coordinated way that takes into account ecosystem vulnerability and responses to projected climate conditions, considers existing and future ecosystem uses and non-climate drivers, and supports effective governance ( ''high confidence'' ).

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