It makes up your hospital, your fresh water and water treatment plants, your power plants,

the roads and bridges you drive on, your office, and maybe even your home.

Concrete is the world's number one construction material and will be for the future.

It's great but it has a dirty little secret.

Its production produces 8% of the entire world's carbon dioxide emissions.

A problem we're going to try to fix today on Skeptoid.

You're listening to Skeptoid. I'm Brian Dunning from Skeptoid.com.

Why you need to care about concrete?

Today we're going to point our skeptical eye at concrete, specifically at the popular

figure of 8% of all greenhouse gas emissions that concrete is said to be responsible for.

That's 2.8 gigatons a year as of 2020.

If that number is true, then that's wildly out of control.

In fact, if the global concrete industry was a country, it would be the world's third

largest emitter of carbon, after only China and the United States.

We humans use more concrete than any other substance except water, and the reason is that

it's great, it's inexpensive, the structures we create from it are extremely durable,

and it's easy to work with, being formable into any shape.

We're going to use even more of it in the future, about one quarter more than today,

as places like China, India, and Africa continue to build out their modern infrastructure.

So if that 8% number is even close to true, we may have a real problem on our hands.

Our first step in answering this question is to reverse engineer concrete to see what

its components are, and maybe along the way see if any of them can be provided differently

...