Hotter temperatures brought by climate change are already bringing additional challenges to world agriculture–more weather extremes including more drought, more flooding, and more high heat all of which damages crops causing lower yields and lower nutritional content.
A new study confirms another threat. A study from 2008 showed that “as temperatures rise, nearly all insects multiply and rev up their metabolisms.” More heat means “living things start to speed up, and they need to consume more calories.” Even without warming temperatures, “insects already consume 5% to 20% of major grain crops” worldwide.
The new study used a computer model “that combined physiological data on hundreds of insect species with climate models.” Studies predict that global wheat crops will decrease by 46%, rice crops will decrease by 19%, and corn crops will decrease by 31% as the Earth warms by an average of 2 degrees C by the year 2100, if not sooner.
On top of those losses, “yield lost to insects will increase by [another] 10% to 25% per degree C of warming” especially for corn and wheat. These losses due to increased insects will have the greatest impact in temperate areas worldwide like the corn belt in the United States Midwest where large amounts of grain are currently produced.
While other factors might impact and possibly limit the predicted insect crop losses, the United Nations estimates that at least “815 million people worldwide already go hungry every day, and corn, rice, and wheat are the main food sources for about 4 billion people.” “The people hardest hit by crop loss will be the world’s poorest households.”
We need to plan for this added impact on the global food supply. Read the article (Frankie Schembri, Science, August 30, 2018).