The Real Reason to Worry About GMOs — They Encourage the Massive Use of Herbicides

Monsanto's genetically engineered crops are designed to withstand Monsanto's powerful herbicides.  This herbicide immunity encourages farmers to saturate GMO crops with  herbicides (some of which have been deemed potentially cancerous). The overuse of herbicides promotes the development of weeds that are evolving an immunity to the herbicides, which causes farmers to use even more herbicides - manufactured by Monsanto, of course.—Ronald David Jackson

Photo by Kevin Krejci.

By Tom Philpott
In a recent column, the New York Times' Mark Bittman makes an important point about the controversy around genetically modified foods. "[T]o date there's little credible evidence that any food grown with genetic engineering techniques is dangerous to human health," he writes. Yet the way the technology has been used—mainly, to engineer crops that can withstand herbicides—is deeply problematic, he argues.

Here's why I think Bittman's point is crucial. The below chart, from the pro-biotech International Service for the Acquisition of Agri-biotech Applications, gives a snapshot of what types of GMO crops farmers were planting as of 2012. In more recent reports, the ISAAA doesn't break out its data in the same way, but it's a fair assumption that things are roughly similar three years later, given that no GMO blockbusters have entered the market since.

If you add up all the herbicide-tolerant crops on the list, you find that about 69 percent of global GM acres are planted with crops engineered to withstand herbicides. But that's an undercount, because the GM products listed as "stacked traits" are engineered to repel insects (the Bt trait) and to withstand herbicides. Adding those acres in, the grand total comes to something like 84 percent of global biotech acres devoted to crops that can flourish when doused with weed killers—chemicals that are sold by the very same companies that sell the GMO seeds.

As Bittman points out, almost all of the herbicide-tolerant crops on the market to date have been engineered to resist a single herbicide, glyphosate. And weeds have evolved to resist that herbicide, forcing farmers to apply heavier doses and or added older, more toxic chemicals to the mix.

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