Miller Magazine Issue: 139 July 2021

24 MILLER / july 2021 NEWS Up to 40% of global crop production is lost to plant pests and diseases, says the U.N. Food and Agri- culture Organization. Each year, plant diseases cost the global economy more than $220 billion, and invasive insects cost at least $70 billion. Ravenous pests are on the march to colder regions as climate change lures crop eaters to new territories, threatening jobs and exacerbating world hunger, the United Nations said. From fall armyworms to desert lo- custs, the pests mostly menace crops in hot countries but the rise in world temperatures was now fanning their expansion, the U.N. said, with all the risks that entails for farmers and their families. "The impact of climate change is one of the greatest challenges the plant health community is facing," Qu Dongyu, director-general of the Food and Agriculture Organization, said after releasing a study covering 15 invasive pests and diseases. With up to 40 percent of global crop production already lost to pests, according to FAO estimates, any migration into new land could see the scale of that destruction shoot higher. "Some pests, like fall armyworm (which feeds on a growing number of crops, including maize, sorghum, mil- let) and Tephritid fruit flies (which damage fruit and oth- er crops), have already spread due to warmer climate," said a statement by the FAO. "Others, such as the des- ert locust (the world's most destructive migratory pest), are expected to change their migratory routes and geo- graphical distribution because of climate change." There was an increased risk of pests spreading in agricultural and forestry ecosystems, especially in cooler Arctic, bo- real, temperate and subtropical regions, it said. A single, unusually warm winter, for example, may be enough to assist the establishment of invasive pests, it added. Each year, plant diseases - ranging from coffee leaf rust to banana fusarium wilt - cost the global economy more than $220 billion, and invasive insects such as des- ert locusts and red palm weevils at least $70 billion. The U.N.'s FAO says the global yield losses of major staple crops such as wheat, rice and maize are projected to in- crease by 10%-25% per degree of global average surface warming. Not only will this have major economic consequences on developing countries, where crops such as tea, cof- fee, and fruits are key export earners, but it will also hit smallholder farmers who will not be able to grow enough to eat or sell. Last year, massive desert locust swarms - some the size of cities - swept across Somalia, Ethiopia and Kenya, feasting their way through hundreds of thou- sands of hectares of crops and grazing land. Climate scientists say erratic weather linked to global warming created ideal conditions for the insects to carry out a surge in numbers not seen in a quarter of a centu- ry. Warmer seas have led to more cyclones in the Indian Ocean, causing heavy rainfall along the Arabian peninsula and the Horn of Africa - the perfect environment for breed- ing, they said. Governments, supported by U.N. agencies and international charities, were forced to respond with large-scale aerial and ground spraying of pesticides to de- stroy the swarms. "The key findings of this review should alert all of us on how climate change may affect how in- fectious, distributed and severe pests can become around the world," said FAO's Dongyu. 40% of global crop production is lost to pests