September 27, 2016

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Environmental Impacts

The early warnings of environmentalists about the negative impacts of genetically engineered plants are, unfortunately but inevitably, being proven correct. In addition to ongoing concerns about the impact of GM insect resistant (Bt) crops on soil ecosystems and non-target insects we see the following serious problems:

  • Contamination: Contamination from GM plants is having ecological and economic and social impacts.
  • Superweeds: In 2010 the development of herbicide tolerant (HT) weeds became a serious problem in the U.S and in HT weeds are now becoming a problem in Ontario and Alberta.
  • Superpests: In 2011 insects that developed resistance to GM Bt (insect resistant) plants were being observed.
  • Increased Pesticide Use: GM insect resistant (Bt) crops produce their own toxin and do not reduce or eliminate insecticides, but simply change the way that pesticides are used, from sprayed on, to built in. US and Latin American data show that GM herbicide tolerant crops have increased overall pesticide use, and have dramatically accelerated the emergence and spread of resistant weeds.
  • Decrease in Biodiversity: The expansion of corn and soy crops in North America, particularly GM herbicide-tolerant corn and soy which is twinned with herbicides, has destroyed much of the weedy habitat of monarch butterfly.

Contamination

Once genetically engineered organisms are released into the environment, they cannot be recalled and they cannot be controlled.

Increased Pesticide Use

GM insect resistant (Bt) crops produce their own toxin and do not reduce or eliminate insecticides, but simply change the way that pesticides are used, from sprayed on, to built in.

U.S. and Latin American data show that GM herbicide tolerant crops have increased overall pesticide use, and have dramatically accelerated the emergence and spread of resistant weeds.

"Soybean production in the Souther Come of the Americas: Update on Land and Pesticides Use" January 2012. Compiles and analyzes specific data on land and pesticide use in the main soybean producing countries of the Southern Cone of South America: Argentina, Bolivia, Brazil, Paraguay, and Uruguay.

Below is a summary of "Implications of GM crop cultivation at large spatial scales", Presentation given in Bremen, Germany, June 14-15, 2012 , By Charles Benbrook, PhD, Center for Sustaining Agriculture and Natural Resources, Washington State University, Pullman, WA

The following is based on U.S. Department of Agriculture data.

Increased herbicide use on GM RR soy compared with non-GM soy:
*Use of glyphosate on GM RR soy acres INCREASED from 0.69 pounds per acre in 1996 to 1.56 in 2011.
*Use of other herbicides on GM RR soy acres DECREASED from 0.20 pounds per acre in 1996 to 0.12 in 2011.
*Use of all herbicides on GM RR soy acres INCREASED from 0.89 pounds per acre in 1996 to 1.68 in 2011.
*Use of all herbicides on non-GM soy acres DECREASED from 1.19 pounds per acre in 1996 to 0.96 in 2011.

GM soy vs non-GM soy:
The differential between herbicides used on GM RR soy and non-GM soy is growing, showing that GM RR soy is increasing the use of herbicides over time whereas non-GM soy is decreasing herbicide use. In 1996 GM RR soy needed 0.30 pounds per acre less herbicide than non-GM soy. But in 2011 GM RR soy needed 0.73 pounds per acre more herbicide than non-GM soy.

Increased herbicide use on GM herbicide-tolerant (HT) crops as compared with non-GM crops in 2011:
*0.73 pounds per acre more in the case of soy
*0.41 pounds per acre more in corn
*0.86 pounds per acre more in cotton.
Impacts of HT crops on herbicide use 1996-2011:
*Herbicide-tolerant (HT) crops have INCREASED herbicide use by a total or 527 million pounds (239 million kgs)
*HT soybeans account for 72% of the total increase in herbicide use across the three HT crops.

Bt crop impacts on insecticide use and overall GM crop impacts 1996-2011:
*Bt corn and cotton have REDUCED chemical insecticide spray use by 124 million pounds (56 million kgs).
*GM crops have INCREASED overall pesticide use by 403 million pounds (183 million kgs).
This means an additional 0.25 pounds (0.28 kg/ha) of active ingredient for every GM trait acre.

Increase in rate (pounds per acre) of glyphosate applications on GM glyphosate-tolerant corn, cotton and soy:
*Corn: increase of 54% between 1996 and 2010
*Cotton: increase of 206% between 1996 and 2010
*Soy: increase of 96.6% between 1996 and 2006.

The new data is an update of Benbrook’s previous reports of 2004 and 2009. The 2009 report found that herbicide use had increased 383 million pounds (173 million kgs) in first 13 years of GM crop use, due to herbicide-tolerant crops. A modest reduction in chemical insecticide spray applications due to Bt crops (down 64.2 million pounds or 29.1 million kg) was swamped by an overall increase in pesticide use of 318 million pounds (144 million kg).

Biodiversity

Monarch butterflies have declined by more than 90% in under 20 years. It is estimated that the butterflies may have lost more than 165 million acres of habitat in this timeframe — an area about the size of Texas — including nearly a third of their summer breeding grounds. Click here for more information.

Non-Target Effects

The Nature Institute has established a project called "Nontarget Effects of Genetic Manipulation" to "make evidence about the wide-ranging and never wholly predictable effects of genetic engineering readily accessible to concerned citizens, policy makers, and scientists." Click here to read their introductory paper "Understanding the Nontarget Effects of Genetic Manipulation."

"When foreign genes are introduced into an organism, creating a transgenic organism (commonly called a genetically modified or genetically engineered organism), the results for the organism and its environment are almost always unpredictable. The intended result may or may not be achieved in any given case, but the one almost sure thing is that unintended results - nontarget effects - will also be achieved...Nontarget effects within the host organism are not necessarily due only to the gene directly related to the intended effect. There are numerous ways in which the genetic manipulation can affect changes in the host organism. Although the genetic intervention may seem simple, in reality one is dealing with a complex web of relations that can be altered in manifold ways."

Aquatic Organisms

2007 Study Shows Genetically Engineered Corn Could Pollute Aquatic Ecosystems - pollen and other plant parts containing toxins from genetically engineered insect resistant Bt corn are washing into streams near cornfields and lab trials show that consumption of Bt corn byproducts produced increased mortality and reduced growth in caddisflies, aquatic insects that are related to the pests targeted by the toxin in Bt corn.

Other Resources

GMO Inquiry 2015 Are GM Crops Better for the Environment? May 2015, CBAN.

June 2009: CBAN Briefing Note: Genetically Engineered Crops: Irreversible harm to natural ecosystems

Links

Third World Network Biosafety Information Centre for accurate news and detailed reports from around the world.
Union of Concerned Scientists (United States) for background

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