Invasive pests increase greenhouse gas emissions

It’s bad enough that invasive species wreak havoc on ecosystems. Now scientists have found that some of these pests also increase greenhouse gas emissions by prompting widespread use of insecticides.

The study authors examined the effects of the soybean aphid, an agricultural pest that surfaced in North America in 2000. Since then, the pesky bugs have become the continent’s biggest threat to soybean crops. From 1999 to 2006, the amount of insecticide used on soybeans in 12 northern and central U.S. states increased from 15,400 to 900,000 kilograms per year, the team found.

The researchers then estimated the greenhouse gas emissions associated with producing, transporting, and applying the insecticides. About 17 million kilograms of carbon dioxide-equivalent greenhouse gases were emitted per year as a result of these control efforts, the team reports in PLOS ONE. That’s roughly the same amount generated by burning 7.4 million liters of gas.

Most studies tend to investigate how global warming will encourage species invasions, the authors note. They conclude: “Our analysis highlights the fact that invasive pest species are not only affected by global climate change, but they can also affect it”. Roberta Kwok | 22 August 2013

Source: Heimpel, G.E. et al. 2013. Environmental consequences of invasive species: Greenhouse gas emissions of insecticide use and the role of biological control in reducing emissions. PLOS ONE doi: 10.1371/journal.pone.0072293.

Image © Robert J. O’Neil and Ho Jung Yoo, Purdue University | Wikimedia Commons