Modeling the Future of Reefs

Published 2017-01-10

Photo: van Hooidonk et al. 2016

The Paris Agreement, signed by 196 nations in 2016, signaled a turning point in the road to a low-carbon economy and reduced greenhouse gas emissions. Countries involved in this agreement aim to limit global temperature increases to no more than 1.5 degrees Celsius. This effort has important implications for the future of important but vulnerable ecosystems, including tropical coral reefs. In light of this international effort, scientists recently published a study using global climate models to generate projections of the future of coral reefs under the Paris Agreement. Specifically, scientists used these high-resolution models to predict the frequency and location of severe annual coral bleaching events over the next century.

If the Paris Agreement targets are met, it may slow the rate and severity of stressors on reefs, including coral bleaching. The newly published projections show that approximately three-quarters of the world’s reefs will experience annual bleaching by the year 2070. Reefs will begin to experience annual bleaching events by the year 2043, followed by another 5% hit about a decade later, and 11% experiencing annual bleaching about a decade after that. The model projections indicate that reefs in Taiwain and the Turks and Caicos archipelago may be the first locations to experience annual bleaching events followed by reefs in Bahrain, Chile, and French Polynesia. If the targets for the Paris Agreement are exceeded, reefs may have approximately 11 more years before annual bleaching events rise in frequency and severity. Reefs in high or low latitudes (Australia, south Pacific, India, Coral Triangle, Florida Reef Tract) may have 25 or more years before annual bleaching occurs, giving more time for conservation and management efforts.

These predictions have important implications for managers, politicians, and conservation groups as communities decide how to prioritize reef protection and stressor reduction. Efforts may include reducing land-based pollution, managing fisheries effectively, and preventing damage from over-use. Model predictions provide an opportunity for proactive conversation, collaboration and action among scientists, policy-makers, and community members to design management strategies for coral reefs.

Journal Reference:
1. Ruben van Hooidonk, Jeffrey Maynard, Jerker Tamelander, Jamison Gove, Gabby Ahmadia, Laurie Raymundo, Gareth Williams, Scott F. Heron, Serge Planes. Local-scale projections of coral reef futures and implications of the Paris Agreement. Scientific Reports, 2016; 6: 39666 DOI: 10.1038/srep39666