Adopting some of the most stringent measures needed to curb climate change across all industries could cause hunger levels to rise by three times as much as global warming itself, according to a study released on Tuesday.
Including agriculture in plans such as a global carbon tax could put 78 million more people at risk of hunger by 2050 by pushing up the price of food, said the researchers, whose paper was published in Nature Climate Change.
That compares with an estimated 24 million from climate change alone, they said. Globally, 815 million people are already going hungry, according to the United Nations Food and Agriculture Organization (FAO).
"It will become difficult for the poor and vulnerable people to buy enough food," said Tomoko Hasegawa, one of the lead researchers of the paper, which recommends countries instead adopt specific policies for agriculture.
"Some people may also shift from nutrition-rich products to less nutritious food."
Agriculture, forestry and other land uses together account for nearly a quarter of the world's greenhouse gas emissions, according the FAO.
But introducing carbon taxes, expanding biofuel plantations and planting trees — all measures that would help countries meet their commitments under the Paris climate agreement- would increase the cost of food production, the paper said.
"By 2050, stringent climate mitigation policy, if implemented evenly across all sectors and regions, would have a greater negative impact on global hunger and food consumption than the direct impacts of climate change," it said.
"The negative impacts would be most prevalent in vulnerable, low-income regions such as sub-Saharan Africa and South Asia, where food security problems are already acute."
The findings underscore the challenges of cutting emissions produced through agriculture, which experts say is essential to cap the rise in global temperatures at a manageable level as agreed under the Paris deal.
Hasegawa, a scientist with Japan's National Institute for Environmental Studies, said the researchers were not trying to downplay the need for mitigation, but rather wanted policymakers to be flexible in designing policies.
Alternatives to carbon taxes — levies on emissions — include transferring technologies that improve crop yields from developed nations to help vulnerable countries farm more efficiently, she said.
Taxing red meat and dairy products and making farming livestock in developing countries more efficient, could also cut both emissions and improve nutrition, the paper said.
Scientists around the world are already working on making livestock less gassy to fight global warming.
France, Britain, Japan and parts of Canada have introduced carbon taxes, while large agricultural producers including the United States and Brazil have initiated policies to support biofuels, the paper said.