Climate change is already affecting pest pressure in agriculture. A warming climate means pests have more reproductive cycles in a year and better survival over winter, leading to even more pest pressure in the spring. It also increases the risk of invasive and migratory pests and the diseases they carry (1). All of this adds up to more crop loss and food insecurity. How do we deal with increased pest pressure?
More synthetic pesticides are not an option!
Ninety-nine percent of synthetic pesticides are derived from petroleum (2). In 2021, 3.53 million metric tons of pesticides were used globally (3). The average estimated carbon equivalent emissions (CO2e) from pesticide production, packaging, storage, and distribution for active ingredients of 38 different synthetic pesticides is 5.1 kg CO2e/kg (4). The estimated global carbon equivalent emissions for producing the pesticides used in 2021 are 18 million metric tons. The 18 million metric tons of CO2e from pesticides may not look like a lot right now, but this number can increase in a very short time.
Let me tell you how an invasive pest, the soybean aphid, a native of eastern Asia, increased carbon emissions from 0.2 million kg CO2e to 40 million kg CO2e within 6 years (5). It started in the summer of 2000 when they were detected in US soybean fields. Heimpel and colleagues calculated the carbon equivalent emissions (CO2e) from 3 synthetic pesticide applications, chlorpyrifos (an organophosphate), lambda-cyhalothrin, and esfenvalerate (both pyrethroids), to control soybean aphid. Before 2001, less than 25,000 ha of soybeans were sprayed with insecticides. In 2006, after the soybean aphid infestation, 4 million ha of soybeans were sprayed with insecticides with estimated emissions of 10.6 kg CO2e GHG per ha. Greenhouse gas (GHG) emissions increased from 0–0.27 million kg CO2e a year before the soybean aphid invasion to 40 million kg CO2e GHG a year in just 6 years (5). At the time, the area sprayed represented only 19% of the total soybeans planted in 12 states in the US. Today, we have 33.6 million hectares of soybeans planted in the US, according to the American Soybean Association. If our only solution is synthetic pesticides, controlling this one invasive species in one crop would produce 356 million kg CO2e a year in the…