Coral Favorability: Non-Managed Conditions: Intermediate Emissions - Guam

Many aspects of the environment are outside the control of local or regional resource managers. These conditions may require concerted global action to affect change (e.g., water temperatures) or cannot be controlled at all (e.g., wave power). This layer synthesized spatial information for several non-managed conditions to create a relative score for how favorable a given location is for coral growth and survival.

Environmental conditions contributing to this layer included: marine calcite concentration (a proxy for ocean acidification), irradiance (photosynthetically available radiation, or PAR), thermal stress (annual severe bleaching threshold), wave power (per meter of wave front), and proximity to soils eroded by sea level rise.

Projections exist for how some of these conditions may change over the next century based on the trajectory of global greenhouse gas emissions. This project explored how the relative favorability of non-managed conditions could change between the present climate scenario and the rest of the 21st century. This layer represents the future climate scenario for an intermediate emissions scenario (Representative Concentration Pathway 4.5), in which global greenhouse gas emissions peak mid-century and then begin to fall.

Covariation in these conditions was accounted for using principal component analysis (PCA) to form composite variables of conditions that have strong relationships with one another. The resulting principal components were averaged and scaled from 0 (worst) to 1 (best) to produce the coral favorability score for non-managed conditions. These data are provided for the island of Guam as a raster with a resolution of 1500 m.