The following is an excerpt of an article by reporter Marco Giovanntti on the Salon website detailing the sustainability of GMO crops.
Crops are engineered in a number of ways. Often, they are made resistant to an herbicide, so a farmer can spray one on their fields and keep their plots free from weeds without killing the crop itself. Or they can be innately poisonous to its predators, like milkweed is, which reduces the amount of pesticides needed to keep a crop safe.
“Sustainability,” in addition to being a buzzword, is a measure of a local environment’s ability to remain diverse and productive. Studies showthat choosing to farm either non-GM or GM crops doesn’t make much difference when it comes to sustainability. And in both aspects, biodiversity and productivity, GM agriculture has been performing better than non-GM crops for the last 20 years.
Biodiversity
Any kind of farming inevitably results in biodiversity loss: the immense diversity of forests and woods is cleared for the monotony and monoculture of the crops we need for our food, feed, fibers, and fuel. And this deforestation and agriculture account for 20-30 percent of all greenhouse gases emissions.
But cultivating GM crops has proven better for biodiversity than the conventional alternative, because one way to maintain biodiversity in a local ecosystem is to reduce pesticide use. A GM crop can do this by carrying its own defenses, making pesticides less necessary. For instance, “Bt” corn is engineered to be toxic to predators that would otherwise prey on it. They don’t need as much outside assistance in the form of pesticides sprayed over an entire field.
Another upside to GM crops is that the toxin they carry is specific to their predators, making them less harmful than a spray with collateral effects. That means that primary predators like the European corn borer (nicknamed “the billion dollar bug” because of its heavy effects on the corn market) can be precisely targeted, while leaving other harmless, passerby insects unaffected. Such genetic engineering is remarkably efficient – according to a 2014 meta-analysis, GM-based farming has required 37 percent fewer pesticides than conventional agriculture.
The biodiversity of a field can also be monitored through the levels of insects living on it. A recent meta-study based on 839 publications released over 20 years reaches the conclusion that, worldwide, GM corn does not effect the majority of insect families. Basically, no ladybugs or butterflies were harmed - at least, not more than they would’ve been through conventional agriculture. The only insects that were affected by the Bt-corn were the European corn borer (the intended target), the Western corn rootworm, and other corn pests.
Productivity
The productivity of GM plants is typically 20 percent higher than that of non-GM ones, making it an appealing way to approach the pressures of the rising global food demand due to population growth. GM crops are also an appealing approach in the face of climate change and pollution.