The lead author is a scientist at the NOAA Cooperative Institute of Marine and Atmospheric Sciences
MIAMI – The United Nations recently released a new report that predicts future coral bleaching globally. The report’s lead author, Robin Van Hooydonk, is a scientist at the Cooperative Institute for Marine and Atmospheric Studies of the National Oceanic and Atmospheric Administration (NOAA) based at the Rosenstiel School of Marine and Atmospheric Sciences at the University of Miami (UM).
Key findings from the report include:
- Under the aggressive fossil fuel standard SSP5-8.5, annual severe bleaching (ASB) is expected to occur during this century for 100% of the world’s coral reefs. The ASB’s projected average year is 2034, nine years earlier than a global average for RCP8.5 is projected using CMIP5 models. This CMIP5 previous generation of projections of future bleaching conditions indicates an underestimation of the near future threat of severe annual bleaching.
- The expected exposure to annual severe bleaching conditions varies greatly between and within countries under SSP5-8.5. Coral reefs occur with relatively early and late exposure to annual bleaching conditions in all ocean basins; However, some countries have more temporary shelters than others. Six of the 20 countries with the largest coral reef area have more than 25% temporary refuge (i.e., ASB projected after 2044), including: Indonesia (35%), Western Australia (70%), the Bahamas (26%) , Madagascar (30%), India (37%) and Malaysia (47%). Thirteen of the 20 countries with the largest coral reef area have more than 25% of coral reefs that are expected to experience annual bleaching conditions relatively early. Some of these countries include the Philippines, Solomon Islands, Fuji, Cuba, and Saudi Arabia.
- The average year for expected timing of the ASB under SSP2-4.5 is 2045, 11 years after the average year expected for SSP5-8.5. Successful mitigation in line with the Paris Agreement will do little to provide corals with more time to adapt or acclimatize before the severe coral bleaching conditions that occur annually.
- There are three main findings from the projections that assume coral adaptation levels between 0.25 and 2 ° C: 1) each quarter of the hypothetical adaptation adds about 7 years to the expected mean UT annual acute bleaching 2) The vast majority of corals (> 80%) are expected to experience Australian border rituals this century even if we assume 2C of adaptation; 3) There is significant spatial variation in the benefits to corals, in terms of subsequent ASB timing, at each hypothesized adaptation level. The extent to which coral reefs are adapting to rising sea temperatures is unknown, but some level of adaptation is to be expected. Assuming 1C from adaptation, the global average ASB timing is approximately 30 years after no adaptation is assumed.
Van Hooidonk is located at the NOAA Oceanographic and Meteorology Laboratory in the Atlantic Ocean. To view the full report, visit the United Nations Environment Program at https: /
About the Rosenstiel School of the University of Miami
The University of Miami is one of the largest private research institutions in the southeastern United States. The university’s mission is to provide quality education, attract and retain exceptional students, support faculty and their research, and build scholarship for the university’s initiatives. Founded in the 1940s, the Rosenstiel School of Marine & Atmospheric Science has become one of the world’s leading marine and air research institutions. Rosenstiel School offers dynamic, interdisciplinary academics and is dedicated to helping societies better understand the planet, participate in environmental policymaking, and help improve society and the quality of life. For more information, visit: http: // www.