Locust Swarms Could Expand Their Range in a Hotter, Stormier World

A new study has found that rising temperatures could increase the area threatened by crop-devouring locusts by up to 25 percent in the coming decades. This is due to more regions experiencing cycles of drought and heavy rain that create ideal conditions for biblical swarms of locusts.

Locusts have long been a problem for farmers in northern Africa, the Middle East, and South Asia, thriving in hot, dry conditions but needing occasional rainfall to hatch their eggs. Human-caused climate change is heating up their habitats and intensifying sporadic rains, exposing new areas to potential infestations.

Xiaogang He, an assistant professor at the National University of Singapore and one of the study’s authors, warns that this escalation of locust risks in key agricultural regions could worsen existing challenges brought on by climate-driven extremes like droughts, floods, and heat waves.

While climate change may expand the threat of locusts in some areas, it may also make other regions too hot and dry for the insects to survive. This could lead to smaller territories where locusts can multiply and be easier to control with pesticides before outbreaks turn into large-scale plagues.

Scientists have long understood the connection between locusts and weather, climate, and ecology. The insects remain scattered and hidden in arid regions until rainfall triggers their reproduction and the subsequent swarms devastate crops in vulnerable areas.

In 2019, a major locust infestation affected parts of East Africa to central India, prompting efforts by the United Nations and other agencies to protect food supplies for millions of people.

Using mathematical models, Dr. He and his team studied how climate factors influence locust invasions across large areas. They found that seasonal rains can put distant regions at risk of synchronized swarms, potentially leading to widespread crop failures and impacting global food security.

The study predicts that climate change could expand the locusts’ range by 5 to 25 percent by 2100, with new areas like Afghanistan, India, Iran, and Turkmenistan becoming vulnerable. Sociopolitical conditions also play a role in locust risks, as seen in conflict-affected regions like Yemen.

Despite these challenges, Dr. Meynard notes that some countries have improved their monitoring and management of locusts, showing progress in combating this age-old agricultural threat.