A precipitous drop in the value of carbon credits is prompting the closure of programs that pay farmers and ranchers to reduce emissions on their land.

The market for voluntary carbon credits never took off as expected after legislation meant to curb global warming stalled in Congress, industry observers said. Credits sold on the national market — called the Chicago Climate Exchange — have plummeted in value from a peak of more than $7 a ton in-mid-2008 to less than a dime today.

That means farmers and ranchers who are paid to use climate-friendly conservation practices to create the credits aren’t making any money.

Iowa-based AgraGate Climate Credits Corp., which manages carbon credits for farmers across the country, plans to shut down next year.

“Congress did not pass that legislation, and the current climate does not provide any optimism or foresight if you would that a program that would be regulating carbon in a cap and trade scenario is any time in the near future,” said Dave Miller, the company’s chief science officer.

Miller said it now appears the U.S. Environmental Protection Agency may issue its own greenhouse gas regulations under the federal Clean Air Act. But he said he does not believe there will be a place for farmers to earn credits under that regulatory framework.

Miller estimated up to 10,000 farmers nationwide have been involved in agricultural carbon credit programs. Of those, about 4,000 were managed through AgraGate. Many others were part of a program operated by the North Dakota Farmers Union. That program has also stopped accepting new contracts.

The Chicago Climate Exchange has announced it will end its cap-and-trade program this year.