Jack Cutmore-Scott

Thousands of years ago, the Romans invented a material that allowed them to build much of their sprawling civilization.

Pliny the Elder praised an imposing sea wall made from the stuff as impregnable to the waves and every day stronger.

He was right.

Much of this construction still stands, having survived millennia of battering by environmental forces that would topple modern buildings.

Today, our roads, sidewalks, bridges, and skyscrapers are made of a similar, though less durable, material called concrete.

There's three tons of it for every person on Earth, and over the next 40 years, we'll use enough of it to build the equivalent of New York City every single month.

Concrete has shaped our skylines, but that's not the only way it's changed our world.

It's also played a surprisingly large role in rising global temperatures over the last century, a trend that has already changed the world and threatens to even more drastically in the coming decades.

To be fair to concrete, basically everything humanity does contributes to the greenhouse gas emissions that cause global warming.

Most of those emissions come from industrial processes we often aren't aware of, but touch every aspect of our lives.

Look around your home.

Refrigeration, along with other heating and cooling, makes up about 6% of total emissions.

Agriculture, which produces our food, accounts for 18%.

Electricity is responsible for 27%.

Walk outside in the cars zipping past, planes overhead, trains ferrying commuters to work, transportation, including shipping, contributes 16% of greenhouse gas emissions.

Even before we use any of these things, making them produces emissions.

A lot of emissions.

Making materials — concrete, steel, plastic, glass, aluminum, and everything else — accounts for 31% of greenhouse gas emissions.

Concrete alone is responsible for 8% of all carbon emissions worldwide, and it's much more difficult to reduce the emissions from concrete than from other building materials.

The problem is cement, one of the four ingredients in concrete.