Planning for Resilience: Incorporating scenario and model uncertainty and trade-offs when prioritizing management of climate refugia

Climate change has become the greatest threat to the world’s ecosystems.
Locating and managing areas that contribute to the survival of key species
under climate change is critical for the persistence of ecosystems in the
future. Here we identify “Climate Priority” sites as coral reefs exposed
to relatively low levels of climate stress that will be more likely to
persist in the future. We present the first analysis of uncertainty in
climate change scenarios and models, along with multiple objectives, in a
marine spatial planning exercise and offer a comprehensive approach to
incorporating uncertainty and trade-offs in any ecosystem. We first
described each site using environmental characteristics that are
associated with a higher chance of persistence (larval connectivity,
hurricane influence and acute and chronic temperature conditions in the
past and the future). Future temperature increases were assessed using
downscaled data under four different climate scenarios (SSP1 2.6, SSP2
4.5, SSP3 7.0 and SSP5 8.5) and 57 model runs. We then prioritized sites
for intervention (conservation, improved management or restoration) using
robust decision-making approaches that select sites that will have a
benign climate under most climate scenarios and models. The modeling work
is novel because it solves two important issues. 1) It considers
trade-offs between multiple planning objectives explicitly through Pareto
analyses; and 2) It makes use of all the uncertainty around future climate
change. Priority intervention sites identified by the model were verified
and refined through local stakeholder engagement including assessments of
local threats, ecological condition and government priorities. The
workflow is presented for the Insular Caribbean and Florida, and at the
national level for Cuba, Jamaica, Dominican Republic and Haiti. Our
approach allows managers to consider uncertainty and multiple objectives
for climate smart spatial management in coral reefs or any ecosystem
across the globe.