20 points of broad scientific consensus on GE crops

coverBy Pamela Ronald and Karl Haro von Mogel

Just as many on the political right discount the broad scientific consensus that human activities contribute to global warning, many progressive advocacy groups disregard, reject, or ignore the decades of scientific studies demonstrating the safety and wide-reaching benefits of GE crops.  Is political identity more important than science and the environment?

Review your knowledge of food, farming and plant genetics by reviewing this list. It represents specific points of broad scientific consensus: that is, the conclusions of the scientific community based on analysis of thousands of experimental results over the past 10-20 years. For each point, we have provided links to appropriate references. Please let us know which ones we missed.

  1. GE crops currently on the market are safe to eat. (See the European Commission Joint Research Centre, European Food Safety Authority, The American Medical Association, the National Academy of Sciences, and the World Health Organization)
  2. The processes of genetic engineering and conventional genetic modification pose similar risks of unintended consequences.
  3. The risks and benefits of new traits in crops depend upon the traits themselves and not the means of their introduction, whether through GE or conventional means.
  4. The planting of Bt cotton has reduced the use of sprayed insecticides.
  5. The planting of Bt corn in the US has benefited growers of non-GE corn.
  6. Planting of Bt cotton has enhanced yields in China and India.
  7. Planting of Bt cotton has reduced insecticide poisonings of farmers and their families. 
  8. Adoption of Bt cotton enhances insect biodiversity. 
  9. If not properly managed, overuse of Bt spray or Bt crops will lead to Bt resistant insects.
  10. Farmers need to deploy a crop diversity strategy and crop rotation to reduce the evolution of insect resistance.
  11. US farmers that plant BT crops are required to deploy a “refuge strategy”: creating refuges of crop plants that do not make Bt toxins. This promotes survival of susceptible insects and has helped to delay evolution of pest resistance to Bt crops.
  12. Global pest-monitoring data suggest that Bt crops have remained effective against most pests for more than a decade.
  13. Failure to provide adequate refuges appears to have hastened resistance of pink bollworm in India and western corn rootworm in the US to Bt.
  14. Effective methods for slowing the spread of insect resistance include crop rotation, intercropping and planting refuges of non-BT cotton and non-crop species.
  15. Planting of herbicide tolerant (HT) crops has reduced the environmental impact of herbicide use. This is because the reduced tillage associated with planting of HT crops has led to reduced soil erosion and reduced greenhouse gas emissions.
  16. The liberal use of glyphosate without proper management has spurred the evolution of weeds resistant to that herbicide.
  17. The evolution of herbicide resistant weeds is a problem for farmers who rely on a single herbicide.
  18. GE crops are just one of the many tools that can be used to enhance the sustainability of farms.
  19. Papaya genetically engineered for resistance to papaya ringspot virus has protected yields against significant losses from the virus and saved the Hawaiian papaya industry.
  20. Consumption of Golden Rice, within the normal diet of rice-dependent poor populations, could provide sufficient vitamin A to substantially reduce the 6,000 deaths caused every day by vitamin A deficiency and save the sight of several hundred thousand people per year in a cost efficient manner.

In the last few weeks, on various blogs and forums, representatives of the Union of Concerned Scientists have variously supported, rejected or ignored many of these 20 points of scientific consensus. Most often they simply avoid stating their position.

Consider point #1. “GE crops currently on the market are safe to eat.”

Margaret Mellon of UCS recently stated that they “agree that GE products currently on the market–overwhelmingly herbicide tolerant (HT) and BT crops–are unlikely to be allergenic or toxic and on that basis are likely safe to consume. “

That sounds pretty clear right? Mellon, a scientist herself, agrees with the scientific consensus. But a statement on the UCS Web site appears to reject this scientific consensus and instead does some fear mongering: “GE crops do have the potential to cause a variety of health problems and environmental impacts. For instance, they may produce new allergens and toxins, spread harmful traits to weeds and non-GE crops, or harm animals that consume them.” While it is technically true that any new crop, whether it was developed by genetic engineering or conventional plant breeding, poses risks, by excluding conventional methods in their statement (which are the only crops that have so far caused allergies), and by not mentioning the scientific consensus about the safety of GE crops, the UCS is misleading their followers.

This is just one of the many striking examples of why it is difficult to discern whether UCS rejects or accepts the scientific consensus on GE crops. It is not possible to know the reason for their inadequate communication on key points, but what we do know is that the result contributes to the spread of misinformation about plant genetics, which can impair policy-making.

We extend an open invitation to UCS and other advocacy groups to state clearly whether they accept or reject the scientific consensus on these 20 points. We would like to see these groups become a more credible source of scientific information about GE crops to the public. For science-based policy to be effective, policy makers need accurate information.  

In a subsequent post we will address policy implications of the scientific consensus.


Follow Pamela Ronald:
Pamela Ronald is Professor of Plant Pathology and Chair of the Plant Genomics Program at the University of California, Davis, where she studies the role that genes play in a plant’s response to its environment. With her husband, she co-wrote Tomorrow's Table: Organic Farming, Genetics and the Future of Food. Dr. Ronald was one of the co-founders of Biology Fortified.