If South Florida is ground zero for sea-level rise globally, then the Florida Keys are ground zero for sea-level rise in South Florida.

The stunning stretch of islands, rich with history and a destination for locals and tourists is slowly disappearing.

“The Florida Keys have a long history and they have been changing through time. Much of what we see at the surface today in those islands were deposited in shallow seas about 125,000 years ago when sea level was higher than present," University Of Wisconsin’s Andrea Dutton explained. "Then came a cold period known as the Last Glacial Period, and sea level dropped as a lot of the water from the oceans went on to land. Now sea-level rise is picking up again because of human activity warming our atmosphere, melting even more ice, causing the oceans to expand under heating, and so the Keys are starting to drown again.”

Dutton believes that we shouldn’t be asking if it is too late to save the Keys.

“When you talk about saving the Keys, you're talking about saving them the way they are now at this moment in time and they haven't always been like this. They were underwater before and they will be underwater again,” she said. “That doesn't mean it's the end of the Keys or that we can't save something about the Keys that we love. It just means It's going to look different. So maybe now there’s a key that you can't get to by car at all and it becomes an exclusive destination and a place that people really want to flock to and come to and visit because of that aspect, because it's no longer on this busy roadway."

We talked to more than a dozen Keys residents as we were putting this story together and not one of them denies that the ocean is rising and that more of the Keys will be inundated in the coming years, even if nobody agrees on just how long that might be.

But Marathon resident Mark Senmartin believes that the Keys still exist today and the adaptations since Irma will buy more time.

“We are held to the highest building code in the state of Florida," he said. "We're built to withstand 180 mph plus winds.”

There’s no doubt that newer homes are more likely to survive a hurricane's winds and even storm surge, but the existential threat is the rising ocean. Even if we were to magically reverse global warming today, the ocean would continue to rise. That means we can’t just look at where the water is, but where the water will be.

As A.R. Siders reiterated, “You cannot start retreating until you stop advancing and that's important for every community where we are building into the flood plain, where we are filling in wetlands, where we are adding more homes in places we know are flood-exposed today or are going to be tomorrow."