The legendary migration of the monarch butterfly is at risk of disappearing forever. As many as a billion of the iconic black and orange butterflies once traveled 2,500 miles from Mexico, through the Eastern and Midwestern United States, to Canada and back. This year, however, the winter population of monarchs in Mexico numbered only 33 million individuals. Another group of monarchs, the west-of-the-Rockies population that winters in California, is also in steep decline.
The plight of the monarchs is just one of the stark consequences stemming from the industrialization of the U.S. food system. Monarch populations began to decline in the late 1990s, about the same time that biotech giant Monsanto introduced genetically modified (GM) corn and soybeans. According to scientists, this link is no coincidence, but a consequence of the skyrocketing herbicide use spurred by the popularity of GM crops. On Nov. 4, voters in Oregon and Colorado will have an opportunity to speak up for monarchs — and for increased transparency in the U.S. food system — as both states consider bills that require the labeling of genetically modified ingredients in food. [As Milkweed Disappears, Monarchs are Fading Away (Op-Ed )]
GM corn and soy, also known as "Roundup Ready" crops, were specifically engineered to withstand Monsanto's Roundup weed killer. The chemical, sold generically under the name glyphosate, effectively kills all the plants it touches, so it was used only sparingly when it first hit the market in the 1970s. Farmers used other methods to control weeds once their corn and soybeans began to sprout.
When GM crops arrived on the scene, the game changed. Farmers in the Midwest quickly adopted the high-tech seeds, which now dominate the Corn Belt. With these new plants, growers could drench their fields in glyphosate. The use of glyphosate soared ten-fold, with two unintended consequences.
First, the chemical wiped out vast swaths of milkweed, a native wildflower that monarch butterflies need to survive. Scientists now believe this wholesale destruction of habitat is the chief cause of the monarch crisis. Climate change and deforestation in the insects' Mexican wintering grounds are also hurting monarchs.
The rise of glyphosate also spurred the evolution of "super weeds" that are resistant to the chemical. Glyphosate didn't kill these weeds — it made them stronger. (Unfortunately for butterflies, milkweeds didn't turn out to be super weeds.) The appearance of these resistant plants is an ominous sign of an arms race between chemicals and weeds, a war in which GM crops are a dangerous catalyst. In this battle, farmers, and the environment, are on the losing end.
Instead of restricting the use of dangerous chemicals and putting a stop to the war, the U.S. Environmental Protection agency (EPA) has approved the use of a new and potentially more harmful pesticide called Enlist Duo.
Manufactured by another chemical giant, Dow AgroSciences, Enlist Duo is made of glyphosate and an older herbicide called 2,4-D, which is toxic to people. New strains of GM corn and soy are resistant to these weed killers, but the glyphosate in Enlist Duo will continue to harm milkweeds, and hence monarchs. And Enlist Duo raises concerns for human health, too. In people, 2,4-D exposure has been linked to infertility, birth defects and thyroid problems. The EPA approval of Enlist Duo could potentially increase the use of 2,4-D six-fold. This risky course of action will also spur on the arms race between superweeds and chemicals, spawning a new generation of super weeds that will require a yet more powerful pesticide.
That's why NRDC immediately went to court to block the use of Enlist Duo the day the EPA approved it. The agency ignored the impact this new chemical cocktail will have on monarchs, and it seriously underestimated the risks to people's health.
GM crops have a serious impact on pesticide use. That's why initiatives like Oregon's Prop 92 are so important. Labeling gives consumers the opportunity to make more informed decisions about the food they buy. Allowing consumers to vote with their pocketbooks can create an important new incentive for food producers and technology providers to bring the safest, healthiest products to market.
Reuters recently reported that supporters of GMO labels in Oregon and Colorado have been outspent 3-to-1 by deep-pocketed industries campaigning against labeling measures, including food, chemical and seed companies. If the bills pass, it will send a powerful message to food producers and pesticide makers that the public wants healthy food that is produced in harmony with the natural environment — and that is safe for the remaining monarch butterflies that need help more than ever.
Read more from NRDC on its Op-Ed and features page. Follow all of the Expert Voices issues and debates — and become part of the discussion — on Facebook, Twitter and Google+. The views expressed are those of the author and do not necessarily reflect the views of the publisher. This version of the article was originally published on Live Science.