Whether it’s sprayed from a crop duster, or on the shelves of your local home and garden store, Monsanto’s Roundup and similar herbicides are just about everywhere.

In fact, glyphosate, the active ingredient in Roundup, is now the most widely-used agricultural chemical in U.S. history.

So how did we get here? Let’s take a look:

Ever since Monsanto introduced "Roundup Ready" crops, Roundup use has skyrocketed.

Glyphosate was first introduced to the market in 1974, and for the first decade or so that it was around, its use grew, but steadily. By and large it was used sparingly, because it could only be sprayed in places where farmers wanted to kill all the vegetation. Using it directly on crops didn't make much sense.

Fast-forward to 1996, when Monsanto develops “Roundup Ready” crops — seeds that are genetically engineered withstand glyphosate — allowing farmers to spray their entire cropland, not just in between rows of crops.

And it’s not just in the United States — It’s being used around the world as well.

Glyphosate use in the United States is just one part of the story.

Worldwide, its use has skyrocketed over the last 20 years, from 124 million pounds in 1994, to more than 1.8 billion pounds in 2014 — a nearly 15-fold increase.

Roundup Ready crops introduced, and now a huge percentage of crops in the U.S. are herbicide-resistant

Those “Roundup Ready” crops I mentioned before? If you’ll excuse the pun, their role has been growing in recent years as well.

Farmers have adopted these genetically-engineered, herbicide-resistant crops at an alarming rate. By 2013, 93% of all soybean crops, 82% of cotton crops, and 85% of corn crops in the United States were herbicide-resistant.

But weeds started to become resistant — meaning it takes more Roundup to kill them.

One consequence of being able to spray entire farms with Roundup is that the weeds you’re trying to kill can develop resistance to the herbicide. And that’s exactly what’s happening. So-called “super-weeds” are becoming more and more prevalent, requiring more and more Roundup to kill them.

Regulations have also promoted more use.

The EPA’s also been giving farmers the green light to use more and more Roundup. With few exceptions, the EPA has increased the amount of glyphosate allowed to be sprayed on crops over the last two decades.

But right now, the EPA is going through a process of “reregistering” glyphosate. That’s why it’s so important we convince them that unless and until Roundup is proven safe, we need to ban it.

Do you have friends who have concerns about the use of Roundup? Let the numbers do the talking. Share this story.