People must eat less dairy and meat to limit the nitrogen emissions that are produced by animal farming, according to a new report from the UN.
The scientists claim that livestock farming emits around 65 trillion grams (teragrams) of nitrogen a year – which is as much as 68% of all human-made nitrogen emissions.
This amount of emissions exceeds our planet's 'boundary' for nitrogen.
Nitrogen is responsible for global warming, acid rains, and it is killing the life in rivers. Most of the nitrogen emissions come from the production of food for the animals and the manure management systems rather than processing dairy and meat for human consumption.
The problem is that the nitrogen cycle receives far less attention from researchers and decision makers than the carbon emissions, but it comes with the same environmental risk as carbon.
The report published in Nature Food says: "Given the magnitude of its impacts and its central role in both domestic and international nitrogen challenges, the livestock sector urgently requires a global initiative to tackle nitrogen pollution while supporting food security."
"Livestock supply chains are a major source of nitrogen emissions, contributing roughly one-third of global anthropogenic [human-made] emissions, with significant impacts on pollution, climate change and biodiversity losses."
"Technical solutions and good practices, however, may not be sufficient to reduce impacts to acceptable levels."
"In parts of the world, a reduction in the production and consumption of livestock products is probably necessary to keep global nitrogen emissions within planetary boundaries."
Asia is responsible for most of the livestock sector's emissions, the report says.
Most nitrogen emissions occur in the regions of South Asia, East and Southeast Asia and Latin America and the Caribbean, due to the high number of livestock held in backyard systems, unregulated manure disposal and high usage of synthetic fertilisers.
"The livestock sector contributes to global nitrogen flows through the application of synthetic nitrogen-based fertilisers, the management and accumulation of manure, and the transport of nitrogen-rich products such as food and manure," the report says.
Scientists and researchers call for a global initiative to tackle nitrogen pollution.
"Such an initiative should provide a platform for science-based dialogue on policies to mitigate nitrogen pollution from the livestock sector. This integrated approach would also help to address the many trade-offs between nitrogen management and other sustainability goals." the researches say in the report.