Posts Tagged: carbon

PopSci pursues the perfect lawn

Popular Science, the world's largest science and technology magazine, spotlighted the work of UC Riverside Cooperative Extension turf scientist Jim Baird in its May 2010 "Statistically Speaking" feature. Titled "The Perfect Lawn," the full-page story said Baird is bioengineering grass that drinks less water and still earns praise for its lush, emerald green appearance.

"The process is sort of a gladiator academy for grass," PopSci says. The scientists grow promising hybrids, then turn off the water to see which ones survive.

The article opens with statistics on turf grass' ability to sequester carbon. U.S. lawns, it says, could trap enough carbon each year to offset the emissions from burning 1.9 billion gallons of gasoline. However, it takes 7 billion gallons of water a year to keep the grass green.

Other statistics in the feature were:

• 625 square feet - Area of lawn needed to make enough oxygen for one person for one day
• 1.57 billion hours - Time homeowners spend mowing the lawn per year
• 37 billion pounds - Carbon dioxide that residential lawns can store per year
• 800 million gallons - Amount of gas guzzled by lawn mowers annually
• 33,000 square miles - Area of the U.S. covered by residential lawns

What is the value of a feature in Popular Science, a magazine with a 1.3 million monthly circulation? Stories are probably better-read than ads, and a full-page, four-color ad costs $124,135, according to the magazine's published rates.

Jim Baird

Chinese delegation visits Marin research site

A delegation from China's Ministry of Agriculture visited a Marin County ranch on Wednesday to view a collaborative research project aimed at sequestering carbon in rangeland. The visit was covered by Contra Costa Times reporter Mark Prado.

The research collaborators, which includes UC Cooperative Extension, are studying whether application of compost on rangeland will boost plant growth, which in turn would store more carbon. Research leader UC Berkeley professor Whendee Silver shared with the delegation promising early results gleaned from the first year of the five-year project.

"Plants are pulling carbon out of the atmosphere and ... they put it below ground into soils, into their root systems," Silver was quoted in the story. "You can see that our experimental plot is much greener than the control plot. We grew much more grasses by adding compost."

The Chinese visitors' interpreter, Charles Han, told the reporter the visitors wanted to learn more about the process, according to the article.

"They are very interested in land and grass issues," Han was quoted. "We have a lot of land in China."

The Marin Carbon Project is being conducted on Nicasio Native Grass Ranch and involves the Marin Agricultural Land Trust, USDA Natural Resources Conservation Service, Marin Organic, UCCE in Sonoma and Marin counties, the Marin Resource Conservation District, and the UC Berkeley Department Science, Policy and Management Department.

More information is on the Marin Carbon Project Web site.

Rangeland owners may be able to sequester more carbon on their land.

Media look to agriculture for global warming relief

As protests at the Copenhagen "climate summit" heat up and talks reach a critical stage, the media are looking at a variety of ways humans can slow carbon emissions into the atmosphere, such as changing the way we farm.

In an Ask Pablo column on a Web site called Treehugger, writer Pablo Paster considers whether people should go back to using horses instead of tractors to farm. At first glance, I thought the piece was meant to be humorous, but in fact, Paster researched whether such a change would reduce greenhouse gas emissions.

Among the data Paster used to support the idea was a 2008 UC Davis Cooperative Extension cost study on wheat production. The columnist noted that UC scientists determined it takes 5.43 gallons of fossil fuels per acre to produce 3.25 tons of wheat.

"When combusted this fuel turns into 122 pounds of carbon dioxide (CO₂). Although this number is not going to be the same for every crop we can assume that it is within the right range for all grain crops," Paster wrote.

Combining this information with other data he collected, Paster concluded that tractors emit 122 pounds of CO₂ per acre compared to the 21.5 pounds of indirect emissions from the horse. "If the horse feed were also cultivated by horses this number would be even smaller," Paster wrote.

He acknowledged the difficulty of producing all the world's food using horses, but said small-scale, organic farms could find many advantages to using draft horses.

"Horses have a lower upfront cost and their fuel (feed) also costs less, they tread lightly on the ground, and they even bring their own fertilizer to the fields," he wrote.

Meanwhile, National Public Radio reporter Christopher Joyce joined UC Berkeley environmental science professor Whendee Silver on a visit to a Marin County research site where she is looking at the use of compost on rangeland to increase its carbon-holding capacity.

The compost, a mix of plant clippings and animal manure, "increases plant growth, it actually also lowers the temperature a little bit, so the soil doesn't get quite as hot, it doesn't stimulate as much microbial activity."

The taller grass and minimized soil activity mean the acreage stores more carbon.

"Hopefully, (farmers will) be able to participate in a carbon market, where we can quantify how much carbon is being stored on the land, and they can sell that as a carbon offset," Silver told the reporter.

'Low carbon diet' reduces food's footprint

Every Tuesday, students at the University of San Francisco are presented with "low carbon" diet choices in the school cafeteria, according to a story in the San Jose Mercury News. Gone is cheese pizza and hamburgers. Such savory treats are being substituted with options that are equally delicious - like guacamole and cucumber relish - but are produced on farms that release less greenhouse gasses than dairies and livestock operations.

USF is one example of institutions looking at changing food consumption to reduce the amount of greenhouse gases floating into earth's atmosphere. According to the article, the United Nations reported in a 2006 publication, "Livestock's Long Shadow," that the livestock sector is responsible for 37 percent of human-caused methane release, which is 23 times more potent a heat-trapping gas than carbon dioxide. Livestock emit 65 percent of all human-caused nitrous oxide, which is nearly 300 times the potency of carbon dioxide.

Reporter Suzanna Bohen called UC Davis food systems analyst Gail Feenstra to comment on information from the National Cattlemen's Beef Association. The association's spokeswoman said that critics of beef production's ecosystem effect fail to factor in the environmentally beneficial role of grazing cattle. That includes pastureland absorbing carbon dioxide as it regrows after grazing.

"That's debatable," the article paraphased Feenstra. She is embarking on a project to measure greenhouse gases linked to all aspects of producing agricultural products in California, including feed, fertilizer, energy, transportation and numerous other facets.

Perhaps if cattle were grazing only on unfertilized grasslands, they might provide a net carbon benefit, "however, the proportion of cattle raised in this manner is extremely small," Feenstra was quoted.

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