Designing for climate resilience - an urgent conservation challenge

Tropical coral reefs are home to a quarter of the world's marine species. That richness is underpinned by the complex habitats built by corals that are sensitive to climate change. Projected ocean change under an unmitigated... [ view full abstract ]

Tropical coral reefs are home to a quarter of the world's marine species. That richness is underpinned by the complex habitats built by corals that are sensitive to climate change. Projected ocean change under an unmitigated carbon emission scenario could see reefs lose their most prominent habitat builders already by 2050, and with them the biodiversity, ecosystem services, and livelihoods they support. Importantly, climate change is already affecting sensitive reef corals and is set to compromise reef function even under strong carbon mitigation.

New interventions are now needed to sustain reef resilience under climate change. However, I here show that for such interventions to be effective, they must address three questions: (1) can the target species be sustained in the long-term?; (2) could hardier but less preferred species be effective alternatives for ecosystem services in the long-term?; and (3) when should a conservation program decide to switch from supporting sensitive/preferred to instead investing in hardy/less preferred species?

Using modelled examples I argue that reef conservation is now set to become a design challenge under time pressure. Hard choices of what species are to receive resilience support will become necessary to sustain ecosystem functions and services. An understanding of how alternative reef designs will perform (functions, productivity, values) under different climate scenarios need to inform the conservation strategy. Further, the timing of such a switch from Plan A to Plan B species should be informed by projected rewards vs risks, and the likelihoods of different climate trajectories.