Credit: WILLIAM WEST / AFP / Getty Images

Back in school, most of us learned about Australia’s Great Barrier Reef. Colorful and filled with life, this coral reef system — the largest in the world — is named one of the seven natural wonders of the world. But due to global warming, it’s not what it once was.

In 2016, a marine heat wave killed a significant amount of the coral, creating damage that scientists believe is irreversible. According to a new study featured in Nature led by Terry Hughes, a professor who serves as the director of the ARC Centre of Excellence for Coral Reef Studies, the level of heat was catastrophic and serves as a major threat to the Great Barrier Reef.

This video, originally posted in 2016, shows footage of how dire the situation with the Great Barrier Reef really is.

According to Hughes, the northern third of the reef suffered the most damage due to these weather conditions. The New York Times writes that the scientists took note of which corals were dying, and then went back nine months later to see how many had regained color. The results weren’t good.

Hughes also believes that the reef will never look the same again, which is disheartening.

According to Mark Eakin of NOAA’s Coral Reef Watch, we’ll be seeing a lot less thriving coral until we can figure out how to get a handle on global warming.

Needless to say, the photos are both shocking and sobering. A natural beauty — and a critical part of a larger ecosystem —has been deteriorating due to global warming, and it’s a clear indicator that something’s got to change.