Mapping global marine climate refugia

Meeting the goals of 30×30 and the Kunming Montreal Global Biodiversity Framework requires conservation strategies that protect not only biodiversity hotspots but also the ecological processes that sustain connectivity. Climate change threatens to undermine those efforts in marine regions by shifting species distributions, altering ocean conditions, and destabilizing ecosystems that conservation networks are meant to protect.

Although global marine protected areas and other area-based measures continue to expand, many may not remain effective in the face of accelerating ocean change. A core challenge is identifying which regions of the ocean will stay relatively stable under severe climate scenarios and can therefore serve as long-term anchors for biodiversity conservation.

Zhuang, H., Zhao, L., Wang, Z., Zhang, Z. and Yang, L. 2025. Identifying global marine climate refugia through a conservative approach to ocean biodiversity preservation. Nature Communications, 16(1): 10752. DOI: 10.1038/s41467-025-65791-z.

A new study addresses that challenge by mapping global marine climate refugia and evaluating how well existing conservation networks align with these future-resilient areas. Researchers integrated climate projections from CMIP6 under a worst-case emissions scenario for 2100 with four conservation prioritization layers. They assessed multidimensional climate variability using Zonation to generate a continuous surface of climate stability, then applied Getis Ord hotspot analysis to delineate sensitive zones and stability zones (areas expected to experience the least climate change). Conservation consensus areas were defined as regions recognized by at least two of the four priority frameworks. Marine climate refugia emerged at the intersection of stability zones and conservation consensus areas.

The study reveals that 36% of the global ocean qualifies as sensitive to climate change, while 34% lies within stability zones. Of the conservation consensus areas, 50% fall within stability zones, creating 17.6 million km² of marine climate refugia. Notably, 96% of these refugia occur within exclusive economic zones, and 85% of their total area is concentrated in just 20 large patches. Yet only 14% of existing marine protected areas and other effective area-based conservation measures overlap with identified refugia. As a result, 70% of marine climate refugia remain unprotected, leaving 12.3 million km² of climate-resilient ocean areas vulnerable to future degradation.

The findings illustrate substantial spatial mismatches between current conservation networks and regions most likely to sustain biodiversity under severe climate change. Some of the largest unprotected refugia occur within the exclusive economic zones of Indonesia, French Polynesia, Hawaii, and the Philippines, with individual gaps of over 2.5 million km².

For marine conservation and global 30×30 efforts, these results underscore the importance of explicitly incorporating climate stability and seascape connectivity into spatial planning. Expanding protected and effectively managed areas into identified refugia could raise protection to 14% of the global ocean and 30% of exclusive economic zones. Because 85% of large climate refugia patches span multiple jurisdictions, coordinated transboundary management will be essential. Integrating marine climate refugia into global and national conservation portfolios offers a promising pathway to design networks that remain effective under future conditions and support long-term resilience of marine biodiversity.

State	Year	Policy	Description
New Hampshire	2026	SB592	Enables regional, conservation, and energy resource planning for habitat strongholds and wildlife corridors
New Hampshire	2019	SB200	Requires the New Hampshire Department of Transportation to consider fish and wildlife crossings and mitigation measures in all future road and culvert projects
New Hampshire	2016	SB376	Requires the fish and game department to identify existing and needed wildlife corridors connecting wildlife habitats in the state and to make recommendations for legislative changes

State	Year	Policy	Description
Maine	2023	LD258	Appropriates $7.5 million to Department of Transportation to improve roadways with potential adaptations for wildlife
Maine	2023	LD1881	Establishes compensation fee program relating to fish and wildlife habitats and associated corridors, including compensation paid by solar energy development
Maine	2023	LD508	Requires Department of Environmental Protection to review its permitting laws concerning climate change, habitat connectivity, ecological resilience, and coastal environments

State	Year	Policy	Description
New Jersey	2025	S3618	Directs state agencies to develop a Wildlife Corridor Action Plan
New Jersey	2024	S3916/A5486	Expands eligibility for existing wildlife fencing programs by including farmers leasing farmland
New Jersey	2007	NJAC7:13	Requires the state to incorporate wildlife crossings or a natural bank for terrestrial threatened and endangered species and/or species of concern when a new bridge or culvert project would cause habitat fragmentation

State	Year	Policy	Description
New Mexico	2023	SB72	Appropriates money to new Wildlife Corridors Fund for implementation of wildlife crossing projects under New Mexico Wildlife Corridor Action Plan
New Mexico	2022	HB 2	Allocates funding for projects to reduce wildlife-vehicle collisions and allows the Department of Transportation and Department of Game to implement their Wildlife Corridors Action Plan
New Mexico	2019	SB 228	Requires the creation of a Wildlife Corridor Action Plan that includes comprehensive guidance to agencies for identifying, prioritizing and maintaining important areas for wildlife movement

State	Year	Policy	Description
Washington	2023	HB1216/SB5196	Requires Department of Ecology to prepare environmental impact statements for clean energy projects that consider impacts to habitat connectivity and wildlife migration corridors
Washington	2022	SB5689	Provides funding for US 97 Wildlife Crossing Improvements project
Washington	2019	SEO 1031.02	Recognizes the effect of roadways in creating barriers to wildlife movement, breeding, and migrations; the Washington State Department of Transportation will promote and support Practical Solutions and Planning and Environmental Linkages to integrate habitat connectivity and biodiversity plans; will make use of the highway prioritization map known as Habitat Connectivity Investment Priorities; and will corporate and coordinate with other agencies involved in wildlife habitat protection, specifically along highways

Connecting Science to Conservation

Mapping global marine climate refugia

Zhuang, H., Zhao, L., Wang, Z., Zhang, Z. and Yang, L. 2025. Identifying global marine climate refugia through a conservative approach to ocean biodiversity preservation. Nature Communications, 16(1): 10752. DOI: 10.1038/s41467-025-65791-z.

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About the Author: Heather Cayton

State	Year	Policy	Description
Florida	2024	SB1638	Dedicates annual funding to land purchases, conservation easements, and trail maintenance within Florida Wildlife Corridor
Florida	2023	HB1379	Creates annual appropriation to acquire lands that complete certain linkages and are under high population stress within Florida Wildlife Corridor
Florida	2023	SB2500 sec.146	Provides funding to buy Ocala to Osceola (“O2O”) Wildlife Corridor
Florida	2021	SB976	Tasks state agencies with maintaining wildlife connectivity and designates Florida Wildlife Corridor as an existing physical, geographically defined area
Florida	2021	SB2500	Appropriates $300 million to acquire lands to conserve Florida Wildlife Corridor
Florida	2019	SB7068	Creates a "Multi-use Corridors of Regional Economic Significance Program" that includes protection of wildlife corridors as an intended benefit
Florida	2008	SB542	Amends Florida Forever Act statues to include goals of connecting linkage corridors
Florida	2001	SB1468	Amends Florida Forever Act to establish that land acquisitions should include complete landscape linkages and corridors
Florida	1999	S908	Creates Florida Forever Program, with increased protection of lands that protect threatened or endangered species and plans to create a statewide system of connected landscape linkages