The threat of locusts in a changing climate
Locusts are considered one of the oldest and most devastating pests of world agriculture. These migratory insects, capable of forming swarms of millions of individuals, can destroy entire crops in a very short time, causing famines and serious food crises. Their presence has been recorded since biblical times, but today, with climate change underway, the threat they pose could increase significantly.
Research on climate change and locusts
Recent studies have highlighted how synchronized locust attacks are closely linked to climate extremes of wind and rain. Research suggests that these attacks could become more common with climate change, leading to famine in large areas of Africa, the Middle East and South Asia. The study’s authors predict that lobster habitat could expand by at least 5% by the end of the 21st century, even assuming further reductions in greenhouse gas emissions.
The desert locust: a destructive migratory pest
The Food and Agriculture Organization of the United Nations (FAO) defines the desert locust as “the world’s most destructive migratory pest.” A single individual can eat their own weight in food every day. A swarm can cover an area of approximately 77 square kilometers. It is estimated that a swarm of one square kilometer, composed of approximately 80 million insects, is capable of devouring an amount of crops enough to feed 35,000 people.
The consequences of synchronized attacks
Simultaneous, widespread attacks over long distances not only create a local food crisis after the swarm devours crops, but also cause food insecurity across an entire region, threatening shared international resources. The insect can fly up to 150 kilometers in a single day.
The desert locust crisis of 2020-2021
The video above shows the swarm descending on a single village in South Sudan during the “2020-2021 desert locust crisis,” as defined by the FAO. Listen to the villages cheering the men trying to repel the voracious invaders with clubs, fully understanding the unfolding tragedy. It had been a quarter of a century since Somalia and Kenya had seen such a massive increase, with uncontrolled breeding for several seasons.
Favorable weather conditions and extreme events
The massive outbreak began in early 2020, when millions of locusts swept across the East Africa, Southwest Asia and Red Sea regions. The FAO has stated that favorable climatic conditions have allowed widespread breeding. A series of cyclones have brought heavy rain to areas just north of the Horn of Africa.
The role of climate change
There is increasing evidence that El Niño and La Niña phenomena may be increasing in frequency and amplitude and are associated with greater uncertainties in a warmer climate. A warmer climate will lead to a widespread increase in locust epidemics and new outbreaks will emerge in west-central Asia, posing additional challenges for global coordination of locust control.
Floods and strong winds as triggering factors
Floods and strong winds, as in storms, can cause synchronized attacks and cause epidemics in new regions. The seasonal variation in epidemics is driven by the Intertropical Convergence Zone or ITCZ, a tropical band of clouds and storms responsible for the heaviest rainfall and that moves seasonally from north to south. And its rain facilitates the reproduction of locusts.
Future projection and necessary adaptation
In the long term, the tropical rain belt is expected to shift northward over East Africa and the Indian Ocean in response to climate change. This could lead to a northward shift in the lobster’s breeding belt, which could explain the predicted northward shift of lobster habitat. Locusts lay their eggs in moist sandy soils, so rain is essential for their survival and reproduction. The eggs require moisture in the soil to develop fully. Rain also promotes the growth of plants to nourish their young. Localized rainfall causes locusts to accumulate, accelerating the formation of swarms.
In conclusion, climate change is modifying the ecological and climatic balances of our planet, and with them also the distribution and behavior of species such as lobsters, making it essential to monitor these changes and adopt adaptation and mitigation strategies to prevent the serious consequences that could occur. They arise from more frequent and devastating epidemics.