PORTLAND, Ore. — What if the internet went down, not for just for a few hours or days but indefinitely? No email, no Google, nothing.

It's a pretty troubling scenario and one a University of Oregon researcher says will happen sooner than we may think because critical internet infrastructure will eventually be underwater due to rising sea levels.

Currently thousands of miles of fiber optic cables are buried along our coastlines. These are the cables that make the internet work, but according to the study, are not all waterproof.

The study found about 4,000 miles of those fiber optic cables would be flooded and destroyed as sea levels steadily creep up.

The researchers looked at national sea level rise projections. They quickly discovered it won't be long until that critical internet infrastructure is totally submerged.

Ram Durairajan is a computer scientist at the University of Oregon and an author of the study. He said perhaps one of the most shocking findings of his research was how soon this all could happen.

"This is not in the next hundred years but in the next 15 years," Durairajan said.

The study concludes in a "worst case scenario" more than 4,000 miles of critical infrastructure along U.S. coastlines would be underwater by 2033.

The cities at highest risk are New York, Miami and Seattle.

Durairajan said the key takeaway from his research is that we need to start planning for this possibility sooner than later.