Carbon footprint: Can nature-killing agri be more sustainable?
Modern agricultural systems have achieved astounding gains in productivity in the past 50 years, but they have come at an enormous cost to nature.
Farming is responsible for around a quarter of emissions warping the climate. It’s also one of the primary drivers of biodiversity loss, responsible for threats to 80% of at-risk species, according to the United Nations. Humanity relies on the diversity of plants and animals in the oceans, soils, sky and on land to make the planet habitable, by keeping the air and water clean, providing the basis for many medicines, and pollinating crops.
At the same time, humanity needs to produce enough food for 8 billion people. But there are ways to make the food system more nature- and climate-friendly. “Every cropping system is going to require some simplification of nature and biodiversity. But there are some that are more biodiversity friendly than others,” said Stephen Wood, an agricultural and food systems scientist with The Nature Conservancy and Yale University in the United States.
Clearing of habitat is one of the main forms of farming-driven habitat loss. “That’s happening worldwide at a pretty alarming rate,” Wood told DW. Crop and livestock farming is estimated to occupy some 50% of the world’s habitable land. While ecosystems such as the Amazon, where cattle farmers are clearing rainforest, usually dominate the headlines, important native grasslands in countries like the US are also being plowed up for crops such as wheat.
Intensive livestock farming has the greatest impact on species loss, because of its high emissions, water pollution and the amount of food needed to feed the animals. More wildlife-friendly and traditional methods, like herding cattle across long distances to summer and winter pastures, can bring biodiversity benefits. Grazing animals in these cases helps manage invasive pests and maintain grassland habitats important for ground-nesting birds, for instance, said Wood.
On the consumer-end, one of the best ways to reduce the harm caused by livestock farming is to eat less meat, according to environmental non-governmental organization WWF. Agricultural land use would decline 13% if people simply reduced their consumption of meat and dairy to the recommended dietary amount.
Since the 1940s, giant monocultures have dominated farming, largely replacing small farms that grow multiple crops. The effects on biodiversity have been devastating, said pollination ecologist Barbara Gemmill-Herren.
“With large-scale monoculture, after a while it just becomes a sort of a desert for biodiversity,” said Gemmill-Herren, who is a senior associate at the World Agroforestry Center, an international institute in Nairobi, Kenya.
Bees and other pollinators — a key indicator of broader biodiversity — struggle to service such vast areas of monoculture. These single-crop farms lack other animal and plant species that combat the spread of diseases and pests. That in turn intensifies use of pesticide, herbicide and fertilizer, which can pollute rivers and streams, and damage the soil, as well as the insects and worms that birds feed on.
“Intensive farming of any sort, it’s just inimical to the insects that really need to thrive, and along with insects comes everything else,” said Gemmill-Herren. While monocultures appear to be extraordinarily efficient at producing calories, this simple calculation hides their true cost, according to Gemmill-Herren.