the ocean so hot, it s actually topped whun degrees. this is like a hot tub at this point. eric van damme joined scientists for a dive to see firsthand how this human-caused heat is damaging those critical reefs. reporter: we are leaving the marina on a scientific extradition with some of the world s top coral scientists to determine how the coral reefs off the florida peninsula are coping with unprecedented ocean heat. if anyone can tackle this problem, it s these people. they are inspired and motivated on the front lines of this climate emergency every day. one of the questions we have is what explains why some corals bleach severely and others don t. reporter: scientists aren t just worried about the high water temperatures. they are concerned this is only july and the hottest months are still ahead of us. corals are sensitive to heat. i am a little bit worried we might see quite a few bleached and stressed out coral. reporter: you see, more than 90% of excess feet from gr
problem, it s these people. they re inspired and they re motivated and they re on the front lines of this climate emergency every day. i think one of the big questions we have as scientists is what explains why some corals bleach severely and others don t. reporter: scientists aren t just worried about the high water temperatures, they re concerned this is only july and the hottest months are ahead of us. corals are sensitive to heat. i m worried we ll see a few bleached and stressed out corals. reporter: more than 90% of excess heat from greenhouse warming is stored in our oceans. and that doesn t just disappear. it can supercharge storms, melt our glaciers, and bleach coral reefs. bleached corals are still alive, but they re extremely stressed, highly vulnerable, and if the heat continues, they may die. the first location we dove to was south of key biscayne. i think we saw exactly what we fear, which is that this is the moving front of severe bleaching up through the keys
scorcher, dangerous heat. but we re in key biscayne, in miami specifically because of how that heat has transpired into our oceans directly behind us. we re following up on a very important story, a crucial environmental unfortunately catastrophe that is unfolding right before our eyes, the bleaching and eventual mortality of coral reefs, within this area. we ll highlight that in just one moment. did you know that 90% of excess greenhouse warming is actually stored within our oceans, and it was so apparent this week with temperatures skyrocketing over 100 degrees in the waters behind me. let s talk about the heat wave across the u.s. you mentioned phoenix, this is amazing, just three hours ago temperatures there dropped below 90 degrees fahrenheit for the first time in 16 days. they have never done that. think about what that means for your body, no opportunity to actually get cool overnight when your body anticipates that relief, right? look at this, excessive heat