Global warming is predicted to create hotter and wetter climates in the future—the very climate that weather-dependent pests and pathogens thrive in. In a new meta-analysis published in the journal Nature Climate Change, researchers from the University of Oxford and the University of Exeter looked at how plant diseases and pests will respond to a warming world. They revealed that the range has been steadily shifting toward both poles, as climate change warms higher latitudes. They also found that crop pests have spread north and south at a rate of about 2 miles per year since 1960, but with a lot of variety amongst individual species.
As the fight to end hunger and feed the growing population becomes a main topic of debate around the world, how will the spread of these pests and pathogens pose a challenge to our efforts?
When it comes to the discussion of providing adequate food for the global population, most focus is put on increasing production. Plant pests and disease have historically laid waste to whole harvests. The potato famine of the 1840s was caused by the oomycete Phytophthora infestans, and led to the deaths of approximately 1 million people, and the emigration of an additional 2 million Irish. The 1943 Great Bengal Famine in India led to the deaths of about 3 million people and was caused by just a simple fungus.
Even today, when farmers are better prepared and equipped to control pests and pathogens, between 10 and 16 percent of crop production are still lost to these biological threats. All together, that is enough food to feed hundreds of millions of people.
Changes have already been seen in American species. The mountain pine beetle has migrated to warming forests in the Pacific Northwest, devastating millions of acres of forests–possibly the largest forest insect blight ever seen in North America. The fusarium head blight, another pest that thrives in warmer and wetter conditions up north, has destroyed American wheat and oat crops, resulting in losses of billions of dollars for farmers. And, more pests are steadily making their way northward.
Biotech corporations such as Dow and Monstanto have genetically modified crops to resist certain pests, but studies have shown that these crops have started evolutions of “super-pests” that can withstand pesticides and eat through entire fields. If crop pests and pathogens continue on their current paths toward the poles, the growing world population combined with the increased loss of production will pose a serious threat to global food security.
– Ali Warlich