This is a guest article by Timothy A. Wise, researcher at Tufts University’s Global Development and Environment Institute.

The World Health Organization (WHO) apparently has not gotten the memo about the supposed consensus on GMOs being safe. On March 20, 2015 the WHO’s International Agency for Research on Cancer (IARC) released a new analysis of the evidence on five organophosphate pesticides, including glyphosate, the herbicide in Monsanto’s Roundup weed-killer. The international scientific body concluded that glyphosate is “probably carcinogenic to humans.”

The WHO analysis puts the lie to the supposed “scientific consensus” on the safety of GM crops, declared but not proven by National Geographic, the Gates Foundation, and the Cornell Center for Science, among others. (See my previous article, “The War on Genetically-Modified-Food Critics.”)

The WHO findings, summarized in an accessible two-page monograph and in The Lancet Oncology, raise alarms. Glyphosate is by far the most widely used herbicide because it is the weed-killer that genetically modified corn and soybeans are engineered to “tolerate.” With GM varieties now accounting for 90 percent or more of the U.S. market for corn and soybeans, glyphosate is being liberally sprayed over ever-more-vast tracts of farmland with farmers secure in the knowledge that their crops won’t be harmed by the herbicide.

Apparently humans may not be so tolerant, and animals in feeding trials certainly aren’t.

The WHO found, “For the herbicide glyphosate, there was limited evidence of carcinogenicity in humans for non-Hodgkin lymphoma.” By WHO protocols, “limited evidence” means some evidence but not conclusive evidence. The expert panel cited studies that glyphosate “caused DNA and chromosomal damage in human cells, although it gave negative results in tests using bacteria. One study in community residents reported increases in blood markers of chromosomal damage (micronuclei) after glyphosate formulations were sprayed nearby." Because there have been no long-term human feeding trials, the evidence is limited, mainly to studies of agricultural exposures.

Human feeding trials are considered unethical, so the gold standard for epidemiological research is the animal study. WHO found, in its year-long expert scientific review of the evidence from government and peer-reviewed studies, that “there is convincing evidence that glyphosate also can cause cancer in laboratory animals.”

That finding makes glyphosate a “probable carcinogen” for humans, according to accepted WHO standards.

That probably will not quiet the consensus campaigners, but it should. Will the Gates-funded Cornell Center for Science declare the members of WHO’s International Agency for Research on Cancer to be “science doubters” on GM food safety? Probably. That’s what the center is funded to do.

Et tu, National Geographic? How about a correction or a retraction of your assertion that such scientists are no more credible than creationists?

The first retractions came from investors: Monsanto stock was down sharply on the news.