When Mark Isbell, a third-generation rice farmer in central Arkansas, tallies up his profits for this year, he’ll count a few extra dollars from a unique source: the greenhouse gases that his 3,200-acre farm didn’t emit.

Isbell is part of a small group of farmers participating in a new project piloted by the Environmental Defense Fund (EDF), in conjunction with the USDA, and approved by the American Carbon Registry. The program encourages rice farmers in California and the Mid-South to adopt a series of greenhouse-gas mitigating practices on their fields by allowing them to cash in on the carbon emissions that they offset using California’s carbon market.

“You always have to be looking forward,” Isbell told ThinkProgress. “It seems like this is the direction everything is going. We’ve always focused on efficiency and trying to take advantage of new opportunities. Though there is a small amount of risk, we felt like the potential reward outweighed that. We thought that we might as well go on the adventure and give it a try.”

Isbell is participating in the project along with 20 other farmers who collectively cultivate 22,000 acres of rice across the United States. According to Robert Parkhurst, director of agricultural greenhouse gas markets for the Environmental Defense Fund, that participation is equal to just under one percent of all rice farmers in the United States — and while that seem like a small slice of agriculture’s addition to greenhouse gas-fueled global warming, Parkhurst sees it as a meaningful first step towards getting farmers to adopt practices that could help stave off the worst of climate change.

“Having just shy of one percent of all rice growers in the U.S. say I’m interested in participating is huge,” he said. “We’re looking at doing this with fertilizer across the U.S. We’re looking at doing this with range land. At some point we might be able to do this with enteric fermentation. This is the thin edge of the wedge, if you will.”

Creating a market for carbon

Parkhurst first had the idea to look at greenhouse gas emissions from rice farming in 2006, after California passed its landmark Global Warming Solutions Act of 2006. The legislation, which in addition to mandating that the state cut its greenhouse gas emissions to 1990 levels by 2020, created a statewide carbon market.

But Parkhurst and a colleague noted that in the bill, agriculture was left out — and they wondered what, if anything, they could do about it.

Between 2000 and 2013, agriculture accounted for about 8 percent of California’s total greenhouse gas emissions. Of those emissions, most are either methane — from livestock production or methane-producing crops like rice — or nitrous oxide, from fertilizer.

Parkhurst knew that California rice farmers had a reputation for being forward-thinking environmentalists; the tagline for the California Rice Commission is “The Environmental Crop.” In the 1990s, the California Rice Commission supported a bill that phased out the burning of rice straw, which was degrading air quality in the Central Valley. In the Rice Commission, Parkhurst hoped that he would find allies in the fight to bring agriculture into California’s new carbon market.

Growing rice, mitigating carbon

Together with the California Rice Commission, EDF worked with scientists and farmers in California and the Mid-South to calculate the amount of greenhouse gases that could be offset by implementing a slew of different farming techniques.

Rice is a hugely important staple crop — around the world, some 3.5 billion people depend on rice for a fifth of their daily calories. But rice is also a source of methane, a potent greenhouse gas that is more effective than carbon dioxide at trapping heat in the short term.

That’s because when rice is grown, its root systems secrete carbohydrates created by photosynthesis. Traditional rice farming calls for flooding rice fields after the spring planting until harvest, which creates an oxygen-devoid environment perfect for bacteria that break down the root system’s carbohydrates, emitting methane in the process.

Working with scientists and farmers, EDF was able to calculate reductions in methane achieved when farmers adopted certain techniques, such as sowing rice seeds into dry soil, draining rice fields a few days earlier than normal, or alternating wetting and drying the fields, rather than keeping them wet for the entire season.

“The science wasn’t there in the past,” Parkhurst said, explaining that the program needed a concrete basis in science before it could be incorporated into California’s carbon market. “We didn’t know that these practices would actually decrease greenhouse emissions.”

But some scientists still worry that the science might not quite be at the level needed to consistently and accurately estimate the amount of greenhouse gas emissions offset by adopting different farming techniques. In a January interview with E&E News, Bruce Linquist, an assistant cooperative extension specialist at the University of California, Davis, expressed skepticism that the science could totally back up the offset program.

“Fields are also very different from each other, some are flat and some are sloped so water can saturate one part, and the [other] part is dry. How do you measure and quantify that? It’s a big challenge,” Linquist said, adding that he thought the project had moved “a bit fast.”

Implementing the project in the fields

After nearly two years spent working on the project with scientists, farmers, and the EDF, the California Air Resources Board — which enforces California’s cap-and-trade program — approved the carbon offsets for rice production in June of last summer, and farmers currently participating in the program will start to see the money from their carbon offsets in the coming months.

The offsets are modest — tangible, but not nearly enough to offset the intrinsic risk inherent in switching to more unpredictable methods. As of publication, a ton of carbon was trading in California for a little under $13. The average rice farmer participating in the program can expect to see a half a ton to a ton and a half of carbon offset per acre — after administrative fees, Isbell estimates that he’ll probably pocket between$8 and $10 per acre. As a crop, rice is highly sensitive to moisture. Dry seeding, for instance, can make a rice crop more susceptible to weeds, disease, or pests. Alternate wetting and drying, in the same vein, can leave a rice crop open to reduced yields.

“It’s part of the overall story and we hope it leads to other opportunities, but in and of itself the monetary reward is not where it would need to be to draw the adoption of those techniques,” Isbell said. He hopes that the program could also open up marketing opportunities for their farm, if customers show an interest in rice grown in an environmentally-conscious way and are willing to pay a premium for that product.

But even with the risks involved, Isbell thinks that sustainability-minded rice farmers will show interest in the project.

“I think farmers are by their very nature pioneers in a lot of things,” he said. “If an opportunity presents itself and it seems to be a good thing that could help others and also present an opportunity to profit, then it’s a win-win.”

Isbell, who has been implementing these techniques at his farm since 2013, hasn’t seen any marked reductions in yields. In fact, when he compared a field of rice grown using traditional techniques with a field using methane-reducing techniques, he actually found that the field with the methane-reducing techniques produced a slightly higher yield, though he notes it was within the margin of error. Still, he cautions that his experience is largely anecdotal.

“We did not see an impact, but if you weren’t careful, it definitely could impact the yield,” he said.

Moving beyond rice

The 21 participating farmers represent the first group of American land-crop farmers that will be paid to offset carbon in their fields. But, if Parkhurst gets his way, they will be far from the last.

Rice, while a significant producer of methane, is far from the most egregious agricultural greenhouse gas producer. As E&E News pointed out in January, according to EPA estimates, rice accounted for a little more than one percent of the United States’ overall greenhouse gas emissions in 2013. Even if every single rice producer in the United States participated in the program, it would be but a small dent in agriculture’s overall contribution to climate change.

But Parkhurst hopes that now that the California Air Resources Board has approved one offset project, it will be open to trying more. Specifically, Parkhurst has his sights set on things like fertilizer, which produces nitrous oxide, and the conversion of grassland to farmland, which can release carbon stored in both the grass and the soil.

“With 400 million acres of cropland out there, there’s a huge opportunity,” Parkhurst said, explaining that California can meet up to 8 percent of its carbon-cutting obligations through its carbon market, meaning that some 200 million tons worth of carbon credits can be traded by 2020.

“We’re currently not on a path to generate that full 200 million tons,” Parkhurst said. “I want to change that. I want to change it so that we reach that 200 million ton mark, and I think agriculture is the biggest opportunity to do that. It is the biggest uncapped sector of the economy, and it’s the place where the research is going on right now.”