RIBBON REEFS, GREAT BARRIER REEF, AUSTRALIA CREDIT: MATT CURNOCK / CORAL REEF IMAGE BANK

by Amy Lupica, ODP Contributing Writer

Australia’s Great Barrier Reef (GBR) has been upgraded from “significant concern” to “critical” based on a new report from the International Union for Conservation of Nature (IUCN) that found increasing impacts associated with climate change. Just over one month ago, a study found that half of the coral in the reef has disappeared in the last 25 years due to ocean warming, acidification, and extreme weather. These phenomena pose a major threat not only to the reefs but to the wildlife and human economies they sustain.

Why This Matters: The Great Barrier Reef, the world’s largest coral reef, is one of 83 threatened World Heritage sites. 33% of the 252 World Heritage sites are now threatened by climate change according to the IUCN. It’s is one of the most biodiverse ecosystems in the world. It is home to more than 1,500 species of fish, many of which are crucial not only to sustain other wildlife but to sustain fishing and tourism industries thousands of people rely on for work and income. Without swift action to combat climate change and ocean warming, the Great Barrier Reef will no longer be able to support animal, plant, or human life.

A Worldwide Problem: Across the globe, coral is in decline. Globally, reefs are home to 25% of all marine plants and animals and provide flood protection to 500 million coastal residents. In the United States, some reefs have been left with only 2% of their former coral population, prompting new protections. In Mexico, a national park that managed a reef crucial to buffering the effects of extreme weather went as far as to take out a storm insurance policy on the reef. They hope to use the $850,000 payout they received following Hurricane Delta to rebuild and reinforce their precious reef.  

Despite efforts like these, as well as increased public awareness, researchers have seen that reefs aren’t recovering at the rates they hoped. “Our coral reefs are not just dying. They aren’t coming back,” said Dr. Craig Downs, executive director of the Haereticus Environmental Laboratory in Virginia. Some corals are hundreds of years old and, once they are dead, will take another hundred years to come back in full force. Warming waters and acidification, however, prevent any new growth from taking hold in many reefs. 

Declining Sites: The GBR wasn’t the only site to be upgraded to “critical” by the new report. Protected areas of Mexico’s Gulf of California were also determined to be extremely threatened by climate change. The gulf is the home to the vaquita, labeled the “world’s rarest marine mammal” by the World Wildlife Fund. The GBR and the Gulf of California join 16 other sites labeled as critical by the IUCN. Since 2017, 16 World Heritage sights have shown signs of decline. Only 8 have shown improvement. 

Still, a majority of these sites have a good conservation outlook. Fourty-seven are labeled as “good” and 112 as “good with some concerns,” showing that when action is taken to conserve these ecosystems, it can be very effective. “Natural World Heritage sites are amongst the world’s most precious places, and we owe it to future generations to protect them,” said Bruno Oberle, the IUCN director-general. Oberle said that this new report “reveals the damage climate change is wreaking on natural World Heritage, from shrinking glaciers to coral bleaching to increasingly frequent and severe fires and droughts.” He added, “As the international community defines new objectives to conserve biodiversity, this report signals the urgency with which we must tackle environmental challenges together at the planetary scale.”