This week a new paper entitled Leverage Points for Improving Global Food Security and the Environment was published in the journal Science. (Science Daily summary)
The authors focus on the 17 major crops that account for the vast majority of calories produced and consumed, inputs used and environmental impacts from agriculture. The heavy hitters, no surprises. Corn, wheat, rice and cotton. The big impacts that they focus on are water use; carbon, nitrogen, phosphorus and methane pollution of air and water, and tropical deforestation. The major points of leverage included switching from crops for meat production to crops for human consumption, better irrigation, closing the massive yield gap in countries with low performing agriculture, reducing food waste (especially meat waste) and improving the precision use of inputs like nitrogen and water in countries where overuse is the biggest problem.
Two things might surprise folks who get their sustainable ag news from urban reporters and not from academics. The first is that the percentages of over use of inputs in the US are fairly low and our impact is large, not because our farmers are out of control, but rather that we produce so much freaking food that a few percentage points of over use is a big impact relative to the production in other countries.
The second is the absence of even a mention of pesticides as a major environmental impact anywhere in the paper. Why is this? Because, while pesticides remain a labor issue for farm workers, especially in developing countries, they have improved so much in their mode of action and use in the last half century that they really don't rate as a major environmental impact, at least in comparison to the big foot issues raised in this paper.
The salience of pesticides as an environmental doesn't come from their relative environmental impact, but rather on their psychological impacts. It's better understood by run of the mill chemophobia. Just as we are more afraid of shark attacks than slipping in the shower, pesticides as poisons or carcinogens have a much greater grip on the public imagination than unsequestered carbon, gulf deadzones, or methane pollution. Tropical deforestation may be the biggest agricultural impact, but there aren't many mommy bloggers wondering about how it could affect their kids health. As Steve Savage has explained, neither the ag companies that have improved their products nor the environmental groups that have pushed for improvements have much incentive to publicize the changes, so they go unheralded.
The other reason that it has great salience for the general public is because it is the main political football in the culture war between organic and so-called conventional agriculture. Pesticide use, while not absent from organic farming, is the most visible and highly touted difference that set organic apart. On issues like carbon, methane, nitrogen and phosphorus pollution, organic doesn't have much to brag about. When it comes to the yield gap, it's organic has some splainin' to do.
There is more to look at in this paper, but the absence of pesticides as a major environmental impact was the first thing that popped out at me.