In less than a decade, global warming destroyed 14% of the world's corals: Report
According to the largest ever coral health survey, destructive dynamite fishing, pollution -- but mostly global warming -- has wiped out 14 per cent of the world's coral reefs from 2009 to 2018.
This report titled "Status of Coral Reefs of the World: 2020", is based on nearly two million data points gathered from 12,000 sites in 73 countries, spanning over 40 years. It's the first survey of its kind since 2008 and the sixth global survey of its kind.
The report compares healthy live coral with algae-infested areas, a sign of coral distress, to determine the change over time.
Coral loss varied by region from 2009 to 2018, ranging from five per cent in East Asia to 95 per cent in the Eastern Tropical Pacific. According to more than 300 scientists in the Global Coral Reef Monitoring Network, coral reefs in South Asia and the Pacific, the Arabian Peninsula, and off the coast of Australia were the hardest hit.
"Climate change is the biggest threat to the world's reefs," co-author Paul Hardisty, CEO of the Australian Institute of Marine Science, said in a statement.
Almost 90 per cent of greenhouse gas emissions is absorbed by the ocean, shielding land surfaces but generating huge, long-lasting marine heatwaves that are forcing many coral species past the edge of tolerance.
As a result of a single "bleaching event" in 1998, eight per cent of all corals were destroyed.
Coral reefs cover less than 0.2 per cent of the ocean's surface, yet they are home to almost 25 per cent of all marine animals and plants. They also provide a huge range of benefits to billions of people everywhere, including jobs, and protection from storms and shoreline erosion.
As per the report, including $36 billion in tourism, coral reefs generate 2.7 trillion dollars in goods and services each year.
The 'Coral Triangle'
"Since 2009 we have lost more coral worldwide than all the living coral in Australia," noted UNEP executive director Inger Anderson.
"We can reverse the losses, but we have to act now."
UN's climate science advisory panel, the IPCC, predicts that global warming of 1.5 degrees Celsius above preindustrial levels will lead to the extinction of 70 to 90 per cent of all corals. And only 1 per cent of corals worldwide would survive in a 2 degree above preindustrial levels world.
Surface temperatures on Earth have already risen by 1.1C above this benchmark.
However, according to the report, there are reasons for cautious optimism.
"Some reefs have shown a remarkable ability to bounce back, which offers some hope for the future recovery of degraded reefs," Hardisty said.
Asia's "Coral Triangle," which contains nearly 30 per cent of the world's coral reefs, has been hit less hard by warming waters over the last decade and has even recovered in some cases.