The Facts

• A new study published in Nature on Thursday shows that water temperatures in and around Australia's Great Barrier Reef have reached their highest levels in the past 400 years during the last decade. If the warming continues, the largest living ecosystem on Earth may not survive.

• According to the report, human-caused climate change is the most probable cause of warmer waters. Helen McGregor, one of the co-authors, expressed her extreme concern about the reef, referring to the temperature increases as "unprecedented."

• Repeated bleaching events, which occur when water temperatures rise by more than one degree Celsius (1.8 degrees Fahrenheit), threaten the reef's fragile ecosystem. The heated temperature depletes the coral's nutrients and color.