In case you had any doubt about whether fracking for gas is dangerous, he's going to clear things up a bit for you.
Before he retired, David Letterman was never afraid to speak his mind about issues he cared about.
He gets downright blunt when he's passionate about an issue. Apparently fracking is something that really gets him riled up.
Apparently, he never liked fracking.
Also, known as hydraulic fracturing, fracking is a method of extracting natural gas from deep into the earth. It works by drilling a hole into the ground, injecting a fluid (we still don't quite know what's in that fluid), and forcing natural gas out of shale rocks.
Those who support fracking argue that it's a way to harvest clean(er) energy from the ground — especially when compared to crude oil or coal. Opponents point to some of the environmental issues, but we'll get to that in a moment.
Anyway, the point of the story is that David Letterman really, really doesn't like fracking. At all.
He spoke out about fracking's effect on the environment across much of the country.
He tore into the exemption companies get from having to disclose exactly what's being injected into the earth.
And ended on a less than cheerful note.
So, what's so bad about fracking that it got David Letterman so riled up?
1. It sometimes makes your water flammable.
In places where fracking happens, the water supply can often be tainted with the chemical cocktail energy companies use to extract natural gas.
2. It uses up a lot of water. A lot.
It takes an average of 4.4 million gallons of water to drill and fracture a single natural gas well. That's the same amount that 11,000 families use in a day.
3. It might cause birth defects.
A study showed that congenital heart defects were more commonly prevalent among babies of pregnant women who live close to fracking sites. Other studies have come to similar conclusions.
4. It's been associated with declining home values.
When your water becomes flammable, kids are prone to birth defects and everything else that comes along with fracking, so it shouldn't come as a huge surprise that it's linked to declining home values.