Extreme wind and rain may lead to bigger and worse desert locust outbreaks, with human-caused climate change likely to intensify the weather patterns and cause higher outbreak risks, a new study has found.
The desert locust, known as 'the most destructive migratory pest in the world,' poses a significant threat to agriculture and food security in regions including northern and eastern Africa, the Middle East, and South Asia. These migratory insects travel in swarms of millions, devouring crops along their path and causing famine and food insecurity. A swarm covering just one square kilometer can contain 80 million locusts, capable of consuming enough food crops in a single day to feed 35,000 people.
Published in Science Advances, the study emphasizes that these outbreaks will become increasingly challenging to prevent and control in a warming climate. Climate change-induced extreme weather events, such as more frequent and severe wind and rain, could introduce unpredictability to locust outbreaks. Researchers warn that these circumstances could make it harder for countries to mitigate the impacts on agricultural productivity and food security.
Xiaogang He, the study's author and an assistant professor at the National University of Singapore, hopes that the findings will encourage countries and control organizations to understand and address the repercussions of climate variability on locust dynamics. He emphasizes the need for better regional and continental cooperation to respond quickly and establish early warning systems.
To assess the connection between locust outbreaks and climate change, scientists analyzed data from the Food and Agriculture Organization's Locust Hub from 1985 to 2020. By examining the patterns of desert locusts across long distances, they identified 10 countries, including Kenya, Morocco, Niger, Yemen, and Pakistan, as the most affected by locust outbreaks.
One of the most devastating outbreaks in the past 25 years occurred in East Africa in 2019 and 2020, where the locusts decimated hundreds of thousands of acres of farmland and destroyed crops, trees, and vegetation. This event undermined food security and jeopardized the livelihoods of countless individuals.
Elfatih Abdel-Rahman, a scientist at the International Centre of Insect Physiology and Ecology, warns that widespread locust outbreaks resulting from climate change could pose a substantial threat to affected regions, leading to reduced food production and increased food prices. The researchers additionally found a strong link between the magnitude of desert locust outbreaks and weather and land conditions, such as air temperature, precipitation, soil moisture, and wind. Infestations are more likely in arid areas that experience sudden extreme rainfall, while the number of locusts in an outbreak is significantly influenced by weather conditions.
The study highlights the role of the El Nino climate phenomenon in exacerbating locust outbreaks. El Nino's effects on global weather patterns have been strongly correlated with larger and worse desert locust infestations. Erratic weather and rainfall trigger sudden spurts in vegetation, fueling enormous population growth among locusts. As climate variability increases, experts predict that locust outbreaks will also escalate.
The vulnerability of certain locations, including Morocco and Kenya, remains high, but the study reveals that locust habitats have expanded since 1985. Projections indicate that they will continue to grow by at least 5% by the end of the century, potentially reaching areas in west India and west central Asia.
The study highlights the case of the Rub' al Khali, commonly known as the Empty Quarter, a desert in the southern Arabian Peninsula. Historically, this area has been relatively uncommon for locust outbreaks, but it suddenly became a hotspot in 2019. Uncontrolled breeding following cyclones filled the desert with freshwater lakes, creating ideal conditions for locusts to thrive.
Major locust outbreaks have significant financial implications. The World Bank estimates that it cost over $450 million to respond to a locust outbreak in West Africa between 2003 and 2005. This particular outbreak caused an estimated $2.5 billion in crop damage.
Countries grappling with desert locust outbreaks are already burdened by climate-driven extremes, including droughts, floods, and heatwaves. The escalation of locust risks in these regions could exacerbate existing challenges, worsening food production systems and amplifying global food insecurity.
The study serves as a stark reminder of the urgent need for global action to mitigate climate change and its consequences. Paula Shrewsbury, an entomology professor at the University of Maryland, stresses that societies worldwide must come together to address increasing threats such as desert locust outbreaks. Failure to take action may strain food production systems and escalate global food insecurity.
The findings of this study provide valuable insights into the complex relationship between climate change and desert locust outbreaks. They underscore the importance of proactive measures, regional cooperation, and investments in early warning systems to mitigate the devastating impacts of these destructive pests on agriculture and food security.
