The five members of the Dairy Methane Action Alliance - Danone, Bel Group, General Mills, Lactalis USA, Kraft Heinz, and Nestle - will begin reporting their methane emissions by mid-2024 and will write methane action plans by the end of that year.

Methane is nearly 30 times more potent than carbon dioxide, according to the U.S. Environmental Protection Agency, making it a major focus of attempts to curb global warming.

Reducing dairy methane emissions means providing both technical and financial support to farmers around the world to experiment with possible solutions, like feed additives, said Chris Adamo, vice president of government and public affairs at Danone, on a call with reporters.

"There's not one silver bullet. We have to look at this full spectrum of different options for farms across different geographies," he said.

Danone this year pledged to cut methane emissions from its fresh milk supply chain by 30% by 2030.

Cutting human-caused methane by 45% this decade would keep global warming under 2 degrees Celsius, according to a 2021 assessment by the Climate & Clean Air Coalition and the United Nations Environment Programme.

Companies involved in the new alliance do not need to pledge to reduce their methane emissions by a specific amount, but stronger measurement and reporting are key tools for the companies to eventually reduce their emissions, said Katie Anderson, senior director of the Environmental Defense Fund's business-sector food and forest program, on the press call.

"This is driving more accountability," Anderson said. EDF is convening the alliance.

Globally, food production accounts for about a third of global greenhouse gas emissions. Leaders of this year's COP have pledged the summit will include action on food sector emissions.