The Salt at NPR:
Glyphosate, widely known by its trade name, Roundup, probably gets more attention than any other herbicide. It’s one of world’s most-used weedkillers, and it is also closely linked to the growth of genetically modified crops.
Monsanto invented Roundup, and also invented crops that grow well when it’s used on them. Farmers find that combination almost irresistible.
So in March, when the World Health Organization’s International Agency for Research on Cancer classified glyphosate as a probably carcinogen, it set off a furor. Monsanto was outraged, and vociferously questioned the IARC’s judgement. Opponents of GMOs welcomed the agency’s conclusion as a scientific validation of their cause.