Identifying global marine climate refugia through a conservative approach to ocean biodiversity preservation – Nature

Executive Summary

This report presents an analysis of global marine climate patterns to identify Marine Climate Refugia (MCR) as a cornerstone for achieving global biodiversity conservation targets, with a specific focus on the United Nations Sustainable Development Goals (SDGs). The analysis maps climate-sensitive and stable zones across the global ocean under a worst-case emissions scenario for 2100. MCR are defined as climate-resilient areas that also represent a global conservation consensus. Key findings indicate that MCR span 17.6 million square kilometres, with 96% located within national Exclusive Economic Zones (EEZs). A significant conservation gap is identified, with 70% of MCR currently unprotected. Closing this gap is essential for advancing SDG 14 (Life Below Water) and SDG 13 (Climate Action). The transboundary nature of most large MCR patches underscores the need for international cooperation, aligning with SDG 17 (Partnerships for the Goals). The report recommends prioritizing MCR for the expansion of Marine Protected Areas (MPAs) and Other Effective Area-based Conservation Measures (OECMs) to meet the ’30 by 30′ target.

Introduction: Aligning Marine Conservation with Sustainable Development Goals

The Imperative for Climate-Resilient Marine Conservation

The global ocean, which covers over 90% of the planet’s habitable space, is facing irreversible degradation from anthropogenic activities and climate change. This degradation directly threatens marine biodiversity and undermines the ocean’s capacity to provide essential ecosystem services, jeopardizing progress towards SDG 14 (Life Below Water). Projections indicate that up to 90% of marine life could face a high risk of extinction by 2100. In response, the international community has adopted the ambitious ’30 by 30′ target, aiming to protect at least 30% of marine ecosystems by 2030. However, the effectiveness of existing conservation networks is uncertain due to the escalating impacts of climate change. This study addresses this challenge by identifying climate refugia—areas that remain stable despite climate shifts—as a critical priority for marine conservation efforts, thereby integrating strategies for SDG 13 (Climate Action) into biodiversity preservation frameworks.

Study Objectives

This study aims to identify global Marine Climate Refugia (MCR) by establishing two core criteria:

1. Climate Resilience: The area must demonstrate stability under the most pessimistic climate change scenarios projected for the end of the century.
2. Conservation Consensus: The area must be recognized as a priority for marine conservation by multiple globally representative frameworks.

By delineating these MCR, this report provides a scientifically-grounded foundation for strategic conservation planning that supports the long-term viability of marine ecosystems and helps nations meet their commitments under the Sustainable Development Goals.

Analysis of Global Marine Climate Patterns and Conservation Priorities

Mapping Climate Change Vulnerability

An analysis of future climate variability under the SSP5-8.5 emissions scenario revealed distinct global patterns of climate sensitivity and stability.

• Sensitive Zones: These areas, identified as hotspots of high climate change intensity, cover 36% of the global ocean. They are primarily concentrated in the Arctic Ocean, North Atlantic Ocean, and Southern Ocean.
• Stability Zones: These areas, identified as cold spots with low climate change intensity, cover 34% of the global ocean. They are most concentrated in the southern temperate zone.

These findings are critical for informing climate-adaptive management strategies required to achieve SDG 13 (Climate Action).

Identifying Conservation Consensus Areas (CCAs)

A spatial meta-analysis of four globally recognized marine conservation priority frameworks was conducted to identify areas of international consensus. The analysis found that while 41% of the global ocean is designated as a priority by at least one framework, the overlap between them is limited. Areas where at least two frameworks overlap were defined as Conservation Consensus Areas (CCAs). These CCAs constitute 9% of the global ocean and represent regions with multiple recognized biodiversity benefits, making them prime candidates for enhanced protection under SDG 14 (Life Below Water).

Identification and Characteristics of Marine Climate Refugia (MCR)

Delineation of MCR

Marine Climate Refugia (MCR) were delineated by intersecting the climate stability zones with the Conservation Consensus Areas. This approach ensures that identified MCR are not only important for biodiversity but are also resilient to future climate change, providing a robust strategy for achieving both SDG 13 and SDG 14. The analysis revealed that 50% of CCAs are located within these stable zones, forming the basis of the global MCR network.

Key Findings on MCR Distribution

• Total Area: MCR cover a total of 17.6 million square kilometres.
• Jurisdictional Location: An overwhelming 96% of the total MCR area is located within national Exclusive Economic Zones (EEZs), clarifying the protection responsibilities of coastal states.
• Geographic Structure: The MCR network is composed of 340 independent patches. Twenty of these are large-scale patches (≥150,000 km²) and collectively account for 85% of the total MCR area.
• Transboundary Nature: Sixteen of the 20 large-scale MCR patches (80%) span the EEZs of two or more nations. This highlights the critical need for international cooperation and joint management frameworks, as promoted by SDG 17 (Partnerships for the Goals).

Assessment of Current Conservation Efforts and Gaps

Effectiveness of Existing In Situ Conservation Networks

The report evaluates the alignment of the current in situ conservation network, including Marine Protected Areas (MPAs) and Other Effective Area-based Conservation Measures (OECMs), with climate stability zones. The findings indicate a significant misalignment, posing a risk to the long-term effectiveness of current conservation investments.

• Only 29% of existing MPAs and OECMs are located within climate stability zones.
• Conversely, 27% of these protected areas are situated in sensitive zones, where their future conservation benefits are uncertain.

This analysis demonstrates that current conservation planning does not adequately account for climate change, a critical shortcoming in the global effort to achieve SDG 14.

The MCR Conservation Gap

A substantial gap exists between the identified MCR and the current network of protected areas. A total of 70% of the global MCR area, amounting to 12.3 million square kilometres, remains unprotected. This conservation gap is distributed across 99 EEZs, with the largest gaps found in French Polynesia, Indonesia, and the Philippines. Bridging this gap is essential for building a climate-resilient global marine conservation network.

Recommendations for Achieving Global Conservation Targets

Prioritizing MCR for MPA and OECM Expansion

To effectively advance SDG 14 (Life Below Water) and meet the ’30 by 30′ target, this report strongly recommends that nations prioritize the protection of MCR within their EEZs.

• Closing the identified 70% conservation gap within MCR would increase the proportion of protected EEZs globally to 30%.
• This action would also raise the total global ocean protection coverage to 14%.
• Focusing conservation efforts on MCR ensures that resources are directed towards areas that are most likely to persist and support marine biodiversity in a changing climate.

Addressing Transnational Management Challenges

The transboundary nature of the majority of large-scale MCR patches necessitates a collaborative approach to conservation. Effective management of these shared resources is impossible without robust international partnerships. Therefore, this report calls for:

1. The establishment of bilateral and multilateral agreements for the co-management of transboundary MCR.
2. The development of large-scale, cross-border MPAs to protect entire MCR ecosystems.

These actions directly align with the principles of SDG 17 (Partnerships for the Goals) and are fundamental to securing a sustainable future for the global ocean.

Conclusion: A Conservative Foundation for Sustainable Ocean Management

This report identifies a global network of Marine Climate Refugia that serves as a conservative, scientifically-defensible baseline for preserving ocean biodiversity amid accelerating climate change. The findings reveal that while existing conservation networks are poorly aligned with future climate patterns, a clear opportunity exists to enhance their resilience. By prioritizing the 96% of MCR located within national EEZs, the global community can make significant strides toward the ’30 by 30′ target and fulfill commitments under SDG 14 (Life Below Water). The transboundary nature of these refugia also presents an opportunity to strengthen international cooperation, in line with SDG 17 (Partnerships for the Goals). Integrating MCR into spatial planning provides a critical pathway for implementing effective climate adaptation strategies, as mandated by SDG 13 (Climate Action), and offers the last best hope for marine life in the face of global change.

1. Which SDGs are addressed or connected to the issues highlighted in the article?

SDG 14: Life Below Water

• The article’s central theme is the conservation of marine biodiversity and ecosystems. It directly addresses the threats to marine life from climate change and human activities, and proposes strategies for protection, such as identifying marine climate refugia and expanding Marine Protected Areas (MPAs). The text states, “Global changes threaten marine species, making marine climate refugia essential for biodiversity conservation and climate change mitigation.”

SDG 13: Climate Action

• The article is fundamentally about taking action to combat climate change and its impacts on the ocean. It analyzes the effects of the “worst-case emissions scenario for 2100” and identifies “climate-resilient zones” to serve as refugia. This focus on adaptation and resilience in marine ecosystems is a core component of climate action. The study aims to “mitigate and promote adaptation to climate change” through marine reserves.

SDG 17: Partnerships for the Goals

• The article highlights the need for international cooperation to manage and protect marine ecosystems effectively. It points out that “85% [of marine climate refugia] crossing multiple exclusive economic zones” and that “80% of large-scale patches of MCR span multiple national or regional EEZs,” which presents “challenges for spatial management and opportunities for international collaboration.” This underscores the necessity of transnational partnerships to achieve conservation goals.

2. What specific targets under those SDGs can be identified based on the article’s content?

SDG 14: Life Below Water

1. Target 14.5: By 2020, conserve at least 10 per cent of coastal and marine areas, consistent with national and international law and based on the best available scientific information.
   • The article explicitly discusses this target and its more ambitious successor, the “30 by 30 target,” which aims “to safeguard at least 30% of marine ecosystems by 2030.” It evaluates the current status of marine protection, stating that “MPAs and OECMs cover 10% of the global ocean,” and analyzes how to expand this coverage.
2. Target 14.2: By 2020, sustainably manage and protect marine and coastal ecosystems to avoid significant adverse impacts, including by strengthening their resilience, and take action for their restoration in order to achieve healthy and productive oceans.
   • The identification of “marine climate refugia” (MCR) is a direct strategy to protect marine ecosystems and strengthen their resilience against climate change. The article defines MCR as “climate-resilient zones” and emphasizes that their protection is essential for maintaining healthy oceans.

SDG 13: Climate Action

1. Target 13.1: Strengthen resilience and adaptive capacity to climate-related hazards and natural disasters in all countries.
   • The article’s focus on identifying “stability zones” and “marine climate refugia” is a method for strengthening the resilience of marine ecosystems to the hazards of climate change. These refugia are areas that can maintain stable conditions, thus enhancing the adaptive capacity of marine life.
2. Target 13.2: Integrate climate change measures into national policies, strategies and planning.
   • The recommendation to expand “MPAs and OECMs based on marine climate refugia locations” is a call to integrate climate change adaptation measures (i.e., protecting climate-resilient areas) into national and international conservation planning and policies.

SDG 17: Partnerships for the Goals

1. Target 17.16: Enhance the Global Partnership for Sustainable Development, complemented by multi-stakeholder partnerships that mobilize and share knowledge, expertise, technology and financial resources, to support the achievement of the Sustainable Development Goals in all countries, in particular developing countries.
   • The article’s finding that most large-scale MCR patches “span multiple national or regional EEZs” necessitates international collaboration. It implicitly calls for partnerships between countries to manage these shared resources, addressing “transnational management challenges.”

3. Are there any indicators mentioned or implied in the article that can be used to measure progress towards the identified targets?

SDG 14: Life Below Water

• Indicator 14.5.1: Coverage of protected areas in relation to marine areas.
  • The article provides explicit data for this indicator. It states that “MPAs and OECMs cover 10% of the global ocean.” It further quantifies the potential for progress by noting that closing conservation gaps in MCR “could increase global ocean protection to 14%.” The entire discussion of the “30 by 30 target” is a direct reference to this indicator.
• Indicator 14.2.1: Proportion of national exclusive economic zones managed using ecosystem-based approaches.
  • The article implies this indicator by heavily focusing on Exclusive Economic Zones (EEZs). It finds that “96% [of MCR] within exclusive economic zones” and that protecting these areas could increase “exclusive economic zones protection to 30%.” This suggests a method for measuring progress in managing EEZs through the ecosystem-based approach of protecting climate refugia.

SDG 13: Climate Action

• Implied Indicator for Target 13.1: Identification and protection of climate-resilient areas.
  • While not a formal UN indicator, the article’s methodology of mapping “sensitive and stability zones” and identifying “marine climate refugia” serves as a measurable way to assess progress in strengthening the resilience of marine ecosystems. The total area of MCR identified (17.6 million square kilometres) and the percentage of this area that is protected (30%) are quantifiable metrics of adaptive capacity planning.

SDG 17: Partnerships for the Goals

• Implied Indicator for Target 17.16: Number of transnational agreements or management plans for shared marine climate refugia.
  • The article implies the need for this type of indicator by stating that “85% [of MCR] crossing multiple exclusive economic zones” and “16 patches span multiple EEZs.” Progress towards managing these areas could be measured by the number of countries that enter into collaborative agreements to protect these shared, climate-resilient ecosystems.

4. Create a table with three columns titled ‘SDGs, Targets and Indicators” to present the findings from analyzing the article.

Source: nature.com