Great Barrier Reef at Great Risk

Australia’s Great Barrier Reef at Risk from Global Warming

• Heidi Ridgley
• Apr 01, 2005

AUSTRALIA'S Great Barrier Reef is home to more than 1,500 species of fish, 400 species of corals, 4,000 species of mollusks, 500 species of seaweed and 215 species of birds. But the world’s longest stretch of coral may not make it to mid-century if ocean temperatures continue to climb due to global warming

A recent report based on a two-year study by Queensland’s Centre for Marine Studies predicts that warmer temperatures in the Pacific could kill 95 percent of the reef’s coral by 2050.

Coral—already threatened by the polluted runoff and harmful fishing practices—is fragile. A temperature increase of less than 1.8 degrees F can bleach or kill it. Scientists predict marine temperatures could rise between 3.6 and 10.8 degrees F this century. "Only if global average temperature change is kept to below two degrees C [3.6 degrees F] can the reef have any chance of recovering from the predicted damage," the report cautions. Under this best case scenario, coral would be significantly reduced in this century, but a switch to alternative fuels that don't cause greenhouse gas emissions would allow recovery over the following century. In the worst case, coral populations would collaspe and not likely reestablish themselves in the future.

Moreover, says the report, the demise of the reef—a popular tourist attraction—could end up costing the country’s economy some $6.2 billion in lost income and more than 12,000 jobs by 2020.

John Howard, the country’s prime minister, has made attempts to limit damage to the reef by increasing the area of protected zones where fishing is not allowed from 6,200 square miles to 44,000 square miles. Because healthy coral is more resilient to warmer temperatures, scientists say that reducing the amount of sediment, fertilizers and pesticides would also help.