Ranches now trap carbon in grasslands

03/13/2014

Ask John Wick if the grass is truly greener on his property. It is, he’ll tell you, smiling. It’s darker, denser and better at holding the soil’s moisture, too, he’ll add. It has to be.

The greening grass on his Nicasio ranch has been the favorable outcome of a partnership with land stewardship consultant Jeff Creque and a host of others working with the Marin Carbon Project, a group that is pioneering climate change solutions on grazed rangelands by capturing carbon underground.

The group began as a small, seven-month project funded by a $50,000 grant from the Rathmann Family Foundation. Now in its seventh year, it has grown into a consortium of agricultural groups, university researchers, county and federal agencies and nonprofits. It’s moved beyond controlled test plots on Mr. Wick’s ranch to three full-scale demonstration farms, selected last fall from more than a dozen applicants. Stemple Creek Ranch, Straus Dairy and Corda Ranch are now part of the experiment.

In October, a total of 100 acres of their pastures were blanketed with a one-time application of compost, and project members are developing longterm plans to implement supplementary conservation practices. The science is proven to work, Mr. Wick said, so this demonstration gives a chance to “to see what it looks like on a working landscape” and address more practical concerns like cost.

“Once we concluded the research had proven to be effective in sequestering carbon, we wanted to scale it up, take it on a grander scale,” said Nancy Scolari, the executive director of Marin Resource Conservation District, which is heading up the demonstrations. “What does it look like? What are the trucking costs? What are the economics behind it? We chose three farms where we will be studying not just the effects of compost application, but a whole suite of climate practices.”

If the results align with earlier studies, the three farms could remove 40 tons of carbon from the atmosphere over three years. If projects like it eventually populate half the state’s rangelands, enough carbon could be sequestered in the roots of grasses each year to roughly equal the state’s emissions for all residential and commercial uses, or nearly two-fifths of emissions for electrical generation.

Molecules of carbon are actually quite rare in the earth’s atmosphere, crowded out by nitrogen, oxygen and water vapor. For every one million molecules in the air we breathe, only about 398 are carbon dioxide. So what’s the big deal?

Over the last 800,000 years, including all of human history, carbon dioxide has only exceeded 290 molecules per million within the last hundred years.

A perfect balance of gases is essential for life on earth. The atmosphere absorbs energy from the sun’s rays: most of that energy is reflected back into space but some is trapped and re-directed toward the surface in what is known as the greenhouse effect, similar to light passing through glass to warm a greenhouse. 

Even for its relative scarcity, carbon dioxide is one of the most influential agents in trapping heat, and its increase over the last century from the combustion of fossil fuels like coal and oil and the clearing of forests has drastically intensified the natural process.

With the rapid increase in emissions, scientists have experimented with ways of capturing the excess carbon from our atmosphere. The solutions range from expected to quixotic. There’s Earth Day favorites like restoring wetlands and planting trees. One professor is working on a more efficient artificial tree to vacuum carbon from the atmosphere. Some have proposed injecting gases into depleted oil wells, but there are concerns about leaks and cost. Others want to use the ocean as a “carbon sink,” stimulating phytoplankton growth by fertilizing the surface with added iron or mixing nutrient-rich water from the deep through pipes that stretch miles long, solutions untested on a wide scale that could drastically alter the ocean’s functions.

Mr. Wick and his colleagues founded the Marin Carbon Project to show that solutions need not be so costly or environmentally risky. Instead, they believe an answer could be right under our feet: in our grass, something so ubiquitous it can easily be overlooked, and seemingly just a backdrop. But with adjustments to farms’ fertilization and added conservation measures, the project is hoping to prove the world’s excess carbon can be captured by blades of grass and stored in soil for decades, possibly even centuries.

As grass grows, it converts carbon dioxide from the atmosphere into carbohydrates, drawing its substance literally out of thin air through photosynthesis. Unlike other proposals, grass requires minimal added energy for the conversion, relying entirely on solar energy. While its photosynthetic process of converting carbon dioxide may not be as efficient per acre as that of trees, there’s much more of the green stuff available. Rangelands compose anywhere between one-third and one-half of the global surface area, Dr. Creque said, totaling billions of acres worldwide, with 57 million in California alone.

Grass is also particularly effective at depositing carbon below ground into and through its root system, “an enormous potential reservoir,” where it will remain if undisturbed, Dr. Creque said. The carbon in trees, on the other hand, can be released through human activity—cutting trees down for wood—or by wildfires or rot at the end of a tree’s lifespan.

The beauty of Marin Carbon Project’s plan is that it increases the effectiveness of grasslands through the conversion of a waste product, multiplying the net reduction in emissions. The one-time application of compost can be derived from any compostable material, whether animal waste or urban trash. The process of composting reduces emissions of other powerful greenhouse gases—nitrous oxide and methane from landfills and other sources—providing nutrients to the soil like a slow-release fertilizer and increasing the soil’s water-holding capacity and resilience in the face of drought.

“We’re seeing a whole convergence here of issues, whether it’s water and drought, whether it’s sustainable agriculture, whether it’s ecosystem degradation and restoration and then, of course, all topped off by a climate crisis from the spewing of carbon dioxide into the atmosphere,” Dr. Creque said. “There’s a big, elegant, beautiful and simple solution to all these problems. We feel confident that carbon is the key—not only to the global climate crisis—but to sustainable agriculture and watershed management.”

Some have condemned a grassland-based solution for being too fantastical, providing what they describe as only a minor carbon setback to an increasingly large problem. The process of photosynthesis is limited by the availability of water, an important consideration for grasslands. On a global scale those lands generally predominate in regions with little rainfall, two ecologists at Texas A&M University, Jason West and David Briske, wrote in November. With that limitation, the carbon storage capacity of a blade of grass just can’t keep up with increasing emissions, they say.

“The appeal of this claim to casual observers is enhanced in that it does not require humans to face any tradeoffs. The implication is that we can continue to use fossil fuels and emit carbon into the atmosphere because application of holistic management on the Earth’s grasslands provides a ‘silver bullet’ that will sustainably solve the climate change problem and provide abundant livestock products as well,” Dr. West and Dr. Briske wrote. “We would be thrilled if a simple solution such as this existed. However, it clearly does not, and it is counter-productive to believe that it does. Humanity must look beyond hope and simple solutions if it is to successfully navigate its way.”

With the launch of the demonstration farms, the Marin Carbon Project has set out to prove they are not merely hopeful, but may have a verifiable solution to global warming. Water limitations may be alleviated by the compost, which increases retention of moisture, making the project slightly different than the plans Dr. West and Dr. Briske critiqued. Each ranch’s master plan also addresses water usage, with improvements like installing solar-powered water pumps or developing springs, said Albert Straus, of Straus Dairy in Marshall.

“We want to increase the carbon and fertility in the soil to the point that we capture every drop of rain that lands on the property, so we can have green grass year-round instead of six months a year,” said Loren Poncia, the owner of Stemple Creek Ranch outside Tomales. “What we realize is, the more we take care of the soil, the more production we get off the land.”

After the initial application of compost, the composted patches could already be seen producing more forage than the untouched areas, checkering the landscape with green and brown. 

The trio of ranches was chosen partly for diversity as each will deal with the challenges of a different dairy or beef cattle herd, climate and watershed, said Lynette Niebrugge, a soil conservation scientist with the Resource Conservation District. Each is developing a master plan to maximize its carbon sequestration potential with techniques like compost management, fencing, hedgerow planting or windbreaks and prescribed grazing, she added. 

The American Carbon Registry is currently reviewing Marin Carbon Project’s protocol to certify the carbon-offset practices for the cap-and-trade market, Dr. Creque said, and the National Aeronautics and Space Administration will be monitoring the demonstration farms for productivity, according to Ms. Scolari. 

Interest in the project is scaling up, with possible expansions being considered by Sonoma County and the United States Department of Agriculture. The project has even hosted officials from China’s Ministry of Agriculture interested in bringing the techniques to the other side of the Pacific.

“Take a breath. There’s actually a climate solution in hand here. The physical boundaries of earth’s systems are large enough to remove enough carbon to end global warming. That’s a pretty nice thing to determine,” Mr. Wick said. “Can we get everyone to do it? We’re going to. We have to.”

“It’s all good news,” he added. Pretty soon, it might mean greener grass on a lot more hillsides.