Something's happening in the city and you probably don't know it now.

It has to do with the ground under your feet, but you can't feel it.

And while it may be happening slowly, the consequences could be huge.

Okay.

Are you intrigued Wt Tw news?

bin Abd Ocho explains.

>> Attention Chicagoans brace yourself and Chicago is sinking.

Yes, you heard sinking.

More signs.

name is land subsidence whatever you call it, the city's ascending by more than 2 million each year.

>> That's about a 16th of an inch to get to the bottom of the matter.

You need to one 20,000 years Glacier cover the entire city, the weight of the ice caused downward motion.

And when he was gone, a rebound, the forming Earth's crust as well as helping create our clay bass oil.

>> Fast forward to the we all know about climate change, but Northwestern researchers with the first U.S.

underground climate change and its effects urban infrastructure.

They call it a silent hazard.

installed temperature sensors around the city including below ground.

Turns out the layers of clay and or Chicago are deforming over time due to the rising underground.

Temperatures.

In fact, Northwestern says the underground tents and parts of Chicago have risen 27 degrees since the 1950's.

>> The culprit buildings, transportation systems and other infrastructure creating sheet that safe underground.

>> Open space allows the ground to breathe a So the hottest temps under streets, sidewalks and buildings.

We've got a lot of those.

study of 28 cities revealed at least 20% of the land every one of them is sinking and most have 65% or more subsiding.

Those researchers cite groundwater extraction and expanded urban development has been additional contributing factors and one that even slight downward shift inland to significantly compromise the structural integrity of buildings, roads, bridges and railways overtime.

So what's to be done?

Scientists recommend increasing energy efficiency and reusing so-called he placed on the service before travels underground.

4 starts.

It looks like action today may say future generations of Chicagoans from living in a hole the ground.

>> Or at least from having their buildings.

One.