Humanity’s growing need for food is facing the space need of thousands of other species.
By 2050, humans may have to clear an additional 3.35 million square miles of land for agriculture. Researchers reported on December 21 in Nature Sustainability, making these habitats largely natural, about the size of India, to more than 17,000 vertebrate species from some of their lands.
But changing how, where and what foods are grown can minimize impacts, says conservation scientist David Williams of the University of Leeds in England. "We can feed the planet without destroying it too much."
To find out how, Williams and his colleagues first identified the habitats most likely to be cleared for farmland. The team then calculated the amount of food needed to sustain the projected human population growth for 152 countries and mapped where crops would likely be grown in each, based in part on land use changes. By 2050, the world’s 13 million square miles of land would have to increase by 26 percent, the team found. That growth is concentrated in sub-Saharan Africa, South and Southeast Asia.
The researchers superimposed these estimates on distribution maps of nearly 20,000 species of birds, amphibians, and mammals. Although almost all of these species would lose some habitat, the team estimates that 1,280 species would lose at least 25 percent of their range and 96 species would lose at least 75 percent.
A review of the global food system could almost eliminate these biodiversity losses, according to the team. Among the changes: improving crop yields, the transition to more plant diets, halving food loss and waste, and increasing food imports to countries where agricultural expansion threatens more species. Implementing the four tactics would reduce the world’s crop area by 3.4 million square miles by the middle of the last century and result in only 33 species losing more than a quarter of their natural reach, the team found.
Achieving this may be politically unfeasible, Williams says, but less aggressive changes can still have major impacts. The world needs to feed a growing population, but it can be done more sustainably, he says. "Nothing is done."