Global Coral Reefs Face Imminent Collapse Within 50 Years, IUCN Warns

A stark warning has been issued by the International Union for Conservation of Nature (IUCN), indicating that nearly all of the world's shallow-water coral reefs are at extreme risk of collapse within the next five decades. A new global assessment by the world authority on threatened wildlife classifies a staggering 96 percent of the planet's coral reef systems as "critically endangered," the highest risk category, with the possibility of total extinction by 2075.

Mishal Gudka, scientific lead of the IUCN Red List of Coral Reef Ecosystems assessment, highlighted the severe and looming threat posed by climate change to these vital ecosystems. Corals are highly sensitive to heat and are particularly vulnerable to human-induced climate change, which is causing ocean temperatures to rise and increasing the frequency and intensity of damaging coral bleaching events. The collapse of a reef leads to the disappearance of hard corals, replaced by algae, rubble, and sponges, thereby decimating the diverse ecosystem that supports a wide array of marine life, from small invertebrates to fish like grouper.

Adding to the peril, the emergence of a "super" El Nino this year, a natural warming phenomenon, presents an additional risk to corals, Gudka stated at a press conference during the UN's COP17 biodiversity summit in Yerevan, Armenia. This latest report delivers more grim news for coral reefs, which are crucial for seafood production and tourism, and provide essential protection against coastal erosion and storms. Often referred to as "rainforests of the sea," these reefs boast some of the world's richest biodiversity, supporting a quarter of all marine species, as well as coastal communities and businesses.

Major reef systems globally, including Australia's Great Barrier Reef, the Coral Triangle in the Western Pacific Ocean and Southeast Asia, the Mesoamerican Barrier Reef System, and the Red Sea coral reefs, are now critically endangered, according to the assessment. The IUCN's report utilized a "middle-of-the-road" climate scenario projecting a 2.7C rise in global temperatures above pre-industrial levels by 2100. Their analysis encompassed 127 tropical and subtropical coral systems, covering an area of 188,362 square kilometers.

This assessment follows a recent IUCN study published in the journal Nature, which found that nearly 44 percent of reef-building coral species face an increased risk of extinction due to climate change. Furthermore, a survey from a year prior revealed that harmful coral bleaching had affected 84 percent of the world's reefs, marking the most intense bleaching event on record.

Despite these dire warnings, the IUCN emphasized that coral reefs worldwide are "not yet lost." Gudka noted the remarkable resilience of coral reefs, stating, "Coral reefs have shown a remarkable ability to bounce back from devastating bleaching events." She added, "Pockets of surviving, resilient coral reefs can still remain in the future, so we must do everything within our reach to set them up for success."