It was a blistering closing argument: In concluding the world’s first-ever court case against Monsanto Company over claims its Roundup herbicide causes cancer, attorney Brent Wisner asked jurors to deliver a message so powerful that Monsanto would have to be called to change. 

"Every single cancer risk that has been found has this moment, every single one, where the science finally caught up, where they couldn’t bury it anymore,” Wisner told the jury of seven men and five women. “This is the day Monsanto is finally held accountable.” He implored them to return a verdict that said, “Monsanto, no more.”  The jurors hearing the case in San Francisco Superior Court held the power to return a verdict “that actually changes the world,” Wisner told them. This trial, he said, was the company’s “day of reckoning.”

It is unclear at this point if the jury verdict—$289.25 million, which includes the staggering sum of $250 million in punitive damages—will significantly change the widespread global use of glyphosate. Still, glyphosate-based herbicides like Roundup are facing increasing questions both about their impact on human health,and what damage they might be doing to the environment. 

The verdict handed down August 10 was on behalf of just one individual: school groundskeeper Dewayne “Lee” Johnson, who is dying of non-Hodgkin lymphoma (NHL) he claimed resulted from exposure to Monsanto’s herbicide. But with roughly 4,000 additional plaintiffs with similar cancer-claim lawsuits pending, Monsanto could be facing a tsunami of litigation that could persist for many years and amount to billions of dollars in damage awards to cancer victims and their families. Discovery documents obtained from within Monsanto’s once-secret files in connection with the litigation have fueled outrage at not just the evidence of harm but also of the deceptive tactics Monsanto and chemical industry allies have employed to suppress such evidence. 

Shortly before the verdict, a federal judge in Brazil ruled that new products containing glyphosate could not be registered in the country and existing registrations would be suspended. And in Germany, home to Monsanto’s new parent company, Bayer AG, the environment minister called for the use of glyphosate-based herbicides to be phased out within three years. 

After the San Francisco jury verdict, Italy’s deputy prime minister, Luigi Di Maio, said that there is no longer any doubt about the dangers of the herbicide, and the country needed to fight against further use of it. France’s environment minister, Nicolas Hulot, said the substance must be banned. Hulot said it was not a fight against the interest of farmers but for their benefit. Some British retailers said they were considering pulling the weed-killing products from their shelves.  

Bayer shareholders have reacted with alarm to the verdict, sending shares sliding. While Monsanto has said it will appeal, and insists that it still has the science on its side, legal experts are not confident the company can succeed.  

United States lawmakers and regulators have largely shrugged off the mounting evidence of harm associated with glyphosate herbicides so far. The EPA has issued a review of glyphosate safety that concludes it is not likely to cause cancer and has taken no meaningful actions to limit its use. But as the litigation expands and foreign leaders take action restricting glyphosate products, that could change. 

Glyphosate is considered the world’s most widely used weed killer. Globally, approximately 1.8 billion pounds of the herbicide is used per year, 15-fold increase from the mid-1990s. In the United States, use has grown from roughly 40 million pounds to close to 300 million pounds in that same stretch, according to data compiled by agricultural economist Charles Benbrook.  

Though best known as the active ingredient in Roundup and other Monsanto products, the off-patent chemical is key in many other brands sold by rival chemical companies. Monsanto engineered the rise in use of glyphosate when it introduced genetically altered glyphosate-tolerant crops in the mid-1990s, designed to withstand direct doses of the chemical. 

The “Roundup Ready” cropping system made farming easier and more efficient, but as the use of glyphosate expanded, research surrounding the chemical’s impacts also grew. Researchers have documented a decline in soil health because of overuse of glyphosate, and the chemical has been tied to the declining health of important pollinators, including bees and butterflies. Weed resistance to glyphosate has prompted farmers to combine glyphosate with dicamba and 2,4-D, older herbicides also tied to human health problems. Extensive use of glyphosate leaves residues in food and water, and studies show the chemical is routinely found in human urine. It is so pervasive in the environment that U.S. government researchers have found traces in rainfall. 

The ubiquitous presence of the chemical makes the evidence of ties to disease particularly worrisome. By 2015, the body of scientific evidence tying glyphosate-based herbicides to cancer was strong enough that the World Health Organization’s International Agency for Research on Cancer (IARC) declared glyphosate to be a probable human carcinogen. 

That IARC classification, issued in March 2015, triggered the onslaught of litigation, including Johnson’s lawsuit. All of the lawsuits directly challenge Monsanto’s position that its herbicides are proven safe and assert that the company has spent decades hiding the cancer-causing dangers of its popular Roundup herbicide products. The evidence of deception includes ghostwriting of scientific literature that proclaimed glyphosate herbicides safe and collaborations with certain officials with the EPA to suppress scrutiny of glyphosate-herbicide toxicity.

Monsanto insists it has done nothing wrong, and Bayer officials are standing behind the subsidiary. Monsanto officials said jurors acted on emotion rather than on sound scientific evidence, and they accused Wisner of engaging in misconduct—a “punch below the belt”—by imploring jurors to become part of history with a large damage award for Johnson. They also complained about comparisons between Monsanto’s actions regarding glyphosate and the actions of tobacco industry players in protecting cigarettes, even though lead Monsanto attorney George Lombardi is known in part for also defending tobacco companies in litigation.  

But in issuing punitive damages, the jury found that there was “clear and convincing evidence” that Monsanto’s officials acted with “malice or oppression” in failing to adequately warn of the risks. As defined by the court, those words translate to a determination that Monsanto’s actions were “vile, base, or contemptible” enough to be “looked down on and despised by reasonable people.”

In the days following the verdict, hundreds of potential new clients were inundating law firms with requests to be added to the litigation. Lawyers estimate there could be 10,000 or more plaintiffs in all who will ultimately file claims. 

The next Roundup trial is slated to begin October 22 in St. Louis, Missouri, and involves an Arkansas man diagnosed with non-Hodgkin lymphoma after using Roundup for years. Several more are set for 2019. Lawyers for plaintiffs say they have new evidence that will be presented in the upcoming trials that is even more disturbing than the evidence seen to date.  

"It's the beginning of the end of an era for Monsanto," said attorney Robert F. Kennedy Jr., who assisted in the Johnson case. “This sends a message . . . there are a lot of problems with this product."