PARIS — Ahead of a major global climate change conference to be held in Paris, chief executive officers of top U.S. branded food companies are urging global leaders to take decisive action toward “clear, achievable, measureable and enforceable science-based targets for carbon emissions reductions.”

Signatories to the letter were the c.e.o.s of General Mills, Inc.; Mars, Inc.; Unilever; Nestle USA; Kellogg Co.; Danon (Danone Dairy North America); Ben & Jerry’s; Stonyfield Farm, Inc.; Clif Bar; and New Belgium Brewing Co.

In their letter, the executives made a three-part commitment described as “doing their part” to address climate change issues:

  • “Re-energize our companies’ continued efforts to ensure that our supply chain becomes more sustainable, based on our own specific targets.
  • “Talk transparently about our efforts and share our best practices so that other companies and other industries are encouraged to join us in this critically important work.
  • “Use our voices to advocate for governments to set clear, achievable, measurable and enforceable science-based targets for carbon emissions reductions.”

It was on the latter point the executives said they were seeking progress at the Paris negotiations.

“Now is the time to meaningfully address the reality of climate change,” the executives said. “We are asking you to embrace the opportunity presented to you in Paris and to come back with a sound agreement, properly financed, that can effect real change.”

The executives forthrightly described the risks climate changes poses to the food system.

“Climate change is bad for farmers and for agriculture,” they said. “Drought, flooding and hotter growing conditions threaten the world’s food supply and contribute to food insecurity.

“By 2050, it is estimated that the world’s population will exceed 9 billion, with two-thirds of all people living in urban areas. This increase in population and urbanization will require more water, energy and food, all of which are compromised by warming temperatures.

“The challenge presented by climate change will require all of us — government, civil society and business — to do more with less. For companies like ours, that means producing more food on less land using fewer natural resources. If we don’t take action now, we risk not only today’s livelihoods but also those of future generations.”

The effort to bring the companies together was facilitated by Ceres, a nonprofit sustainability advocacy organization. The letter was published as an advertisement in the Washington Post and Financial Times and was spotlighted in what Ceres called a “bipartisan, bicameral briefing on climate change in Washington.” The briefing was sponsored by Senator Sheldon Whitehouse of Rhode Island, a Democrat, and Representative Chris Gibson of New York, a Republican. The event featured a half-dozen food company executives.

“To reduce emission levels, we must work across our collective value chains with growers, suppliers, customers, peer companies, government leaders and industry partners,” said Kendall J. Powell, chairman and c.e.o. of General Mills. “Together, we will identify new solutions and promote sustainable agriculture practices that drive emission reductions.”

Companies signing the letters are part of the Ceres’ Business for Innovative Climate and Energy Policy, an advocacy coalition seeking the passage of meaningful energy and climate legislation. The group invited other food companies to join the initiative.

The letter was published ahead of the United Nations conference on climate change in Paris Nov. 30-Dec. 11, part of the United Nations Framework Convention on Climate Change. The meeting will be the 21st session of the Conference of the Parties to the United Nations Framework Convention on Climate Change. The gathering serves as the meeting of the parties — more than 190 nations — of the Kyoto Protocol.

“(Paris 2015) will be a crucial conference, as it needs to achieve a new international agreement on the climate, applicable to all countries, with the aim of keeping global warming below 2° centigrade,” according to the U.N. “France will therefore be playing a leading international role to ensure points of view converge and to facilitate the search for consensus by the United Nations, as well as within the European Union, which has a major role in climate negotiations.”