Scientists challenge organic backer Benbrook claims that GM crops increase pesticide spraying

| October 12, 2012 |
Charles_Benbrook

The ongoing hullabaloo over the controversial Seralini study and questions about the safety of foods made from genetic modified crops has obscured another line of attack on biotechnology by the Hydra of GM critics: claims that GM crops are environmentally unfriendly.

Noted organic scientist Charles Benbrook of the University of Washington recently released a summary of his published study assessing the use of pesticides since the introduction of GM crops in the 1990s. A fierce and respected critic of GM technology, Benbrook claims his data shows that pesticide use has gone up in the US over that time.

News coverage of the Benbrook study was motley and often highly politicized. There was the expected selective presentations from anti-GM journalists such as Tom Laskawy at Grist, Tom Philpott at Mother Jones and at organic publisher Rodale. But more disappointing was the botched context provided by more mainstream sources. Reuters, for example, echoed Benbrook’s views uncritically, blaring in a headline that “GMO crop technology backfires.”

Within days of the first wave of media coverage, the more responsible press weighed in and contextualized analysis emerged. Keith Kloor, the respected Slate contributing writer, offered his analysis of how many reporters misplayed the story out of the gate.

Former UC Davis scientist Steve Savage, who had nice things to say about Benbrook, put the organic advocates claims in a different perspective, and reached a far different conclusion. He viewed the extremely modest multi-year increase in the use of some pesticides—less toxic versions than ones used previously—as a sign of significant environmental progress.

The blog Big Picture Agriculture broke down Benbrook’s numbers and found that pesticide use is actually falling on a yield per acre basis—in accord with what biotech proponents have claimed would happen—but warned that trouble may lie ahead.

Environmental consensus emerging on relative safety of GM crops

Benbrook’s broadside aside, what’s most interesting as the debate unfolds are signs that a scientific consensus is gradually but surely emerging that GM crops do not pose unmanageable environmental threats. Supporters and critics of biotech crops agree that crops bred for a natural resistance to pests harm biodiversity less than conventional crops because glyphosate, the pesticide used in conjunction with GM crops, is less persistent in the environment and less toxic to animals.

As New Scientist noted this week conservationists, once diehard opponents, have sharply reduced their vitriolic opposition. It noted, for example, that in 2004, the International Union for Conservation of Nature called for a halt to the release of GM organisms, but by 2007 it had published a report saying there was “no conclusive evidence of direct negative impacts on biodiversity of GMOs that have been commercially released”.

By 2010, Michael Marshall also noted, the once skeptical US National Research Council Reporter had concluded: “[G]enerally, GM crops have had fewer adverse effects on the environment than non-GM crops produced conventionally”. The same year, a European Union report summarized 10 years of research, saying GM crops “are not per se more risky”.

The evolution in views, Marshall wrote, is largely because “claiming that GM crops are environmentally harmful is difficult to back up.” But what about Benbrook’s claims? The magazine quoted scientists who believe there are more than nits to pick with his methodology and conclusions.

Benbrook made subjective estimates of herbicide use because the data, provided by the US National Agricultural Statistics Service, doesn’t differentiate between GM and non-GM crops, said Graham Brookes of PG Economics, a consultancy firm in Dorchester, UK. Brookes crunched the almost identical data and published a peer reviewed report earlier this year that reached a far different conclusion: GM crops may actually have reduced worldwide pesticide use by 9.1 per cent.

The disparity can also be explained by the unique toxic profile of glyphosate. While traditional herbicides don’t work on all weeds, resulting in farmers spraying their fields multiple times, the far more effective glyphosate, which attacks most weeds, can be sprayed fewer times for the same effect.

Every technology comes with trade offs. Farmers have seen an emergence of weed varieties—22 at current count—that are resistant to glyphosate. That’s a problem in conventional agriculture as well of course. So-called superweeds may signal danger ahead—or as New Scientist suggests, perhaps it’s only a temporary reflection of the current market reality that farmers have a limited menu of GM crops to choose from. With more variety of crops using different pesticides, resistant-specific weeds would be less likely to emerge. The issue then morphs into a debate over patent protections and not the science behind GM technology.

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  • http://www.isitorganic.ca/ Mischa Popoff

    I have an idea! Why doesn’t Charles Benbrook debate his claims in an open forum? He could debate Jon Entine, or me.
    In fact, why has there never been such a debate?

    • http://www.survivetime.org/ HenryBowman1776

      Go drink some Glyphosate aka Roundup you Monsanto troll………….

  • Sihegee

    Mischa Popoff I would love to see a real debate real online. we will be in contact with you to see if we can get some real answers.

  • Alex Reynolds

    maybe if Monsanto, with its sordid background and all removed itself from the GMO field, they’d be more accepted. Even GMO supporters dont like Monsanto, its background or its tactics.

    While GMO have been proven not to be dangerous overall, Monsanto and their prior history and agenda IS in question. Especially since glyphosate is no longer as effective as it once was (for the same reason that bacteria have gained immunity against many antibiotics and we need to get them out of our farms). Even GMO supporters see the dangers of a Monsanto monopoly, and want no part of it. I took this off of Monsanto’s own website (dont they ever read?) while the article is pro GMO it does poke holes in Monsanto’s propaganda that their products need less dangerous pesticides. As a matter of fact, Dow and Monsanto could have used much less dangerous pesticides than one of the two main ingredients of Agent Orange, but they chose to use the one they can make the most money from (patent):

    http://www.fitnessmagazine.com/recipes/healthy-eating/nutrition/gmo-facts/

    But less than 20 years later, over a dozen weeds have developed resistance to glyphosate, meaning that farmers have to use more of it, as well as other more hazardous chemicals such as 2,4-D, a powerful herbicide linked to reproductive problems and birth defects, says Chuck Benbrook, PhD, a research professor at Washington State University’s Center for Sustaining Agriculture and Natural Resources. On the basis of 16 years of pesticide data, collected since GMOs were introduced, Benbrook predicts that use of 2,4-D will increase more than fourfold in the next decade, spurred by new GMO crops. “Twenty years from now we will look back and deeply regret the misuse and mismanagement of current-generation GMO technology,” he says.

    This is Agent Orange, the same carcinogen that Monsanto, Dow, Bayer, et. al, poisoned Vietnam and our soldiers with. Now they are trying to patent it as their new pesticide- this is the part everyone should be paying attention to

    These are also interesting reads- illustrative of what may happen in the future

    http://www.npr.org/blogs/thesalt/2012/03/08/148227668/insect-experts-issue-urgent-warning-on-using-biotech-seeds

    http://www.npr.org/blogs/thesalt/2011/12/05/143141300/insects-find-crack-in-biotech-corns-armor

    Note how scientists differed with Monsanto’s assessments and guess who the “regulators” listened to (and you can probably guess why- conflict of interest when they are allowed to be on the regulatory agencies.)

    http://fieldquestions.com/2012/02/12/bt-cotton-remarkable-success-and-four-ugly-facts/

    http://www.reuters.com/article/2014/11/11/us-gmo-science-idUSKCN0IV24C20141111

    But critics of the products say that is not the last word on the issue.

    Some international scientists are challenging the assertion and say many scientific studies show concerns with crops whose DNA has been spliced in ways not seen in nature.

    On Tuesday, a group with backing from institutions in Russia, the United States and Europe said it would undertake the longest, largest and most definitive study of GMOs to date to try to settle the debate once and for all.

    The $25 million study of 6,000 rats to be fed a GMO corn diet is designed as an independent examination of the health impacts of GMO corn and the herbicide used on it. The research is to be done in Russia and western Europe over two to three years. (factorgmo.com/en/)

    “The science on these GMOs is not settled by a long shot,” said Bruce Blumberg, an endocrinology expert at the University of California, Irvine, who sits on the study review board. “Studies that were done by the manufacturers are the main ones showing safety, and those have an inherent conflict of interest.”