In September a condensed version of his position on beef cattle was published as an open source “policy comment” in Food Policy, a leading academic journal in international food and agricultural policy. In October 2025, that comment was picked up and posted in its entirety in Taking Stock, a weekly substack newsletter maintained through the International Livestock Research Institute (ILRI), in Nairobi.

Paarlberg’s policy comment in Food Policy challenged a common assumption that beef cattle grazed on pasture (a dominant practice in the Global South) will be better for the climate than cattle eating grain in a feedlot (the dominant practice now in the Global North). In fact, enteric methane emissions from the mostly “industrial” beef systems in the Global North have seen a significant decline since 1980, even while emissions from the mostly pastured systems in the Global South have increased sharply, and are now roughly four-fifths of all global methane from beef.

The emissions increase in the Global South is no surprise, given strong continuing population and income growth in those countries, but the emissions decline in the Global North calls for an explanation. It does not reflect a production decline; in North America over this period, beef production increased by 29 percent, yet emissions still declined by 16 percent.

The decline was instead driven by improvements in feed rations brought to the animals in feedlots, plus improved animal genetics and veterinary care. These changes reduced the “methane intensity” of beef production: methane emitted per pound of beef produced. These technical changes helped the animals reach a market weight more quickly, reducing the time they spent simply eating to stay alive and belching out methane. As a result, methane intensity in the Global North fell by 36 percent after 1980.  

Thanks to these technical gains in the Global North, animal numbers came down as well. Total beef production in the United States increased by 22 percent after 1980, yet the beef herd declined by 16 percent.  

As consumer demands for beef continue to increase in the Global South, it will be important to transition away from production systems that depend entirely on self-feeding in pastures, which increases CO₂ emissions as well as methane, due to deforestation to create pasture. Comparative studies have shown that pasture-finished systems have a total carbon footprint averaging 42 percent higher than grain-finished beef, even when new carbon sequestration below ground in pastures is taken into account. Environmentalists are suspicious of modern “industrial” beef production systems, but beef consumption in the Global South is certain to continue increasing, so a transition away from exclusive dependence on pastured animals will help keep the environmental damage under control.

Paarlberg is Emeritus Professor of Political Science at Wellesley College, an Associate with the the Mossavar-Rahmani Center for Business and Government at the Harvard Kennedy School, and an Associate at Harvard’s Weatherhead Center for International Affairs. He has published widely on agricultural policy and politics. Paarlberg’s research is supported in part by the Harvard Initiative on Reducing Global Methane Emissions, a research cluster of the Salata Institute for Climate and Sustainability at Harvard University.