Robert Pore's Ag Blog

Scientists at UC Irvine have determined that levels of atmospheric methane – an influential greenhouse gas – have stayed nearly flat for the past seven years, which follows a rise that spanned at least two decades.

This finding indicates that methane may no longer be as large a global warming threat as previously thought, and it provides evidence that methane levels can be controlled. Scientists also found that pulses of increased methane were paralleled by increases of ethane, a gas known to be emitted during fires. This is further indication that methane is formed during biomass burning, and that large-scale fires can be a big source of atmospheric methane.

Professors F. Sherwood Rowland and Donald R. Blake, along with researchers Isobel J. Simpson and Simone Meinardi, believe one reason for the slowdown in methane concentration growth may be leak-preventing repairs made to oil and gas lines and storage facilities, which can release methane into the atmosphere. Other reasons may include a slower growth or decrease in methane emissions from coal mining, rice paddies and natural gas production.

“If one really tightens emissions, the amount of methane in the atmosphere 10 years from now could be less than it is today. We will gain some ground on global warming if methane is not as large a contributor in the future as it has been in the past century,” said Rowland, Donald Bren Research Professor of Chemistry and Earth System Science, and co-recipient of the 1995 Nobel Prize for discovering that chlorofluorocarbons in products such as aerosol sprays and coolants were damaging the Earth’s protective ozone layer.

The methane research will be published in the Nov. 23 online edition of Geophysical Research Letters.

Methane, the major ingredient in natural gas, warms the atmosphere through the greenhouse effect and helps form ozone, an ingredient in smog. Since the Industrial Revolution in the late 1700s, atmospheric methane has more than doubled. About two-thirds of methane emissions can be traced to human activities such as fossil-fuel extraction, rice paddies, landfills and cattle. Methane also is produced by termites and wetlands.

Scientists in the Rowland-Blake lab use canisters to collect sea-level air in locations from northern Alaska to southern New Zealand. Then, they measure the amount of methane in each canister and calculate a global average.

From December 1998 to December 2005, the samples showed a near-zero growth of methane, ranging from a 0.2 percent decrease per year to a 0.3 percent gain. From 1978 to 1987, the amount of methane in the global troposphere increased by 11 percent – a more than 1 percent increase each year. In the late 1980s, the growth rate slowed to between 0.3 percent and 0.6 percent per year. It continued to decline into the 1990s, but with a few sharp upward fluctuations, which scientists have linked to non-cyclical events such as the eruption of Mt. Pinatubo in 1991 and the Indonesian and boreal wildfires in 1997 and 1998.

Along with methane, the UCI scientists also measured levels of other gases, including ethane, a by-product of petroleum refining that also is formed during biomass burning, and perchloroethylene, a chlorinated solvent often used in the dry cleaning process. Ethane levels followed the peaks and valleys of methane over time, but perchloroethylene had a different pattern. This finding provides evidence that biomass burning on occasion, as in Indonesia in 1997 and Russia in 1998, can be a large source of atmospheric methane.

The researchers say there is no reason to believe that methane levels will remain stable in the future, but the fact that leveling off is occurring now indicates that society can do something about global warming. Methane has an atmospheric lifetime of about eight years. Carbon dioxide – the main greenhouse gas that is produced by burning fossil fuels for power generation and transportation – can last a century and has been accumulating steadily in the atmosphere.

“If carbon dioxide levels were the same today as they were in 2000, the global warming discussion would leave the front page. But to stabilize this greenhouse gas, we would have to cut way back on emissions,” Rowland said. “Methane is not as significant a greenhouse gas as carbon dioxide, but its effects are important. The world needs to work hard to reduce emissions of all greenhouse gases.”

NASA and the Gary Comer Abrupt Climate Change Fellowship supported this research.

Peter Kleinman plans to take his research on the road this fall. Every month or so, the Agricultural Research Service (ARS) soil scientist will leave the rolling valleys of Pennsylvania dairy country for corn, crabs and chicken--hallmarks of the Delmarva Peninsula.

The 5,950-square-mile peninsula encompasses parts of Delaware, Maryland and Virginia. There, Kleinman will investigate an experimental method of injecting chicken litter into the soil to keep this natural fertilizer from running off into the Chesapeake Bay.

Each year, Delmarva's 2,700 or so poultry farms raise about 571,141,000 chickens. The 600,000 tons of litter they produce--a mixture of manure and bedding straw--is an ideal fertilizer for corn, soybeans and other Delmarva crops. However, spreading it over the soil surface exposes nutrients like phosphorus to runoff that can drain into the bay's surrounding waters, triggering algal blooms that block sunlight and deprive fish, crabs and other forms of aquatic life of oxygen.

The increasingly popular use of no-till farming compounds the problem, according to Kleinman, with the ARS Pasture Systems and Watershed Management Research Laboratory, University Park, Pa.

Since 2005, he has been researching fertilizer-application equipment called injectors, which squirt liquefied manure below the soil surface. Tom Way, a collaborator with the ARS Soil Dynamics Laboratory in Auburn, Ala., developed the new litter-injector technology. Now, in collaboration with the University of New Hampshire's Cooperative Institute for Coastal and Estuarine Environmental Technology (CICEET) and the National Oceanic and Atmospheric Administration, they're exploring equipment modifications that could enable the injection of chicken litter into the Delmarva Peninsula’s sandy soils.

Their on-site efforts will draw from prior research in which Kleinman and colleagues from ARS, Pennsylvania State University and the University of Maryland-Eastern Shore used a combination of rainfall simulators, runoff monitoring technology and other equipment to examine how well four types of cow-manure injectors curbed runoff and odors emanating from fertilized fields. The project is one of 15 that CICEET is funding nationwide to foster new approaches to safeguarding America's coastal regions.

ARS is the U.S. Department of Agriculture's chief scientific research agency.

LINCOLN – Governor Dave Heineman today received two holiday Norbest-Nebraska Grown turkeys and one Norbest Hickory Smoked turkey from the Nebraska turkey producers in recognition of the upcoming holiday season. The Governor announced that he would donate the turkeys to the People’s City Mission in Lincoln.

“Many of us share in the American tradition of inviting friends and family members over to enjoy companionship and a good meal,” Governor Heineman said. “Here in Nebraska, a large part of that Thanksgiving tradition is supporting our state’s agricultural producers with what we serve. I know that my family and I eat Nebraska-grown Norbest turkeys whenever we can, because of its fresh, high quality taste, and I am pleased to share that tradition with the People’s City Mission and the residents it serves.”


Jerry Felber, President of the Nebraska Turkey Federation, said, “We are pleased to continue the tradition of presenting turkeys to the Governor to kick off the holiday season. We are also grateful for the leadership role Governor Heineman has taken in promoting Nebraska products both domestically and internationally, with an emphasis in value-added agriculture.”

Approximately four million turkeys are produced in Nebraska each year and processed by the Nebraska Turkey Growers Cooperative plant in Gibbon, the state’s only turkey-processing plant. The majority of those turkeys are packaged under the Norbest-Nebraska Grown label. Nebraska cash receipts from turkey production total more than $40 million annually.

The Nebraska Turkey Growers Cooperative has provided quality turkey products for more than 65 years. Norbest is over 70 years old and is the world’s oldest and largest turkey marketing cooperative.

Washington, D.C. — The official signing of a bilateral trade agreement between the United States and Russia means U.S. beef has regained access to the Russian market, effective immediately pending a plant audit tour by Russian inspectors.

“Before December 2003, Russia was a huge export market for U.S. cattle producers,” says South Dakota cattleman Ed Blair, chair of the beef industry’s Joint International Markets Committee. “It’s hard to believe this irrational trade barrier has been unremitting for almost three years now. Cattle producers are relieved Russia has finally acknowledged established international trade standards regarding BSE.”

After site visits from a Russian audit team, the market will immediately open to U.S. boneless beef, bone-in beef and beef variety meats from cattle under 30 months of age with an approved export certificate. The second step in this re-opening process should come in May 2007, when the World Organization for Animal Health (OIE) General Assembly is expected to make its final decision on the United States’ risk-status for BSE.

Pending the determination of the United States as an OIE-designated controlled-risk or negligible-risk country, Russia will reopen to all U.S. beef and beef products from cattle of all ages with the removal of OIE designated specified risk materials.

“Russian consumers devoured our beef products in the past, and it’s about time they got to enjoy our superior exports once again,” says Missouri cattlemen and National Cattlemen’s Beef Association President Mike John. “Cattle producers urge all nations to emulate Russia’s promise to fully re-open to all U.S. beef and beef products pending the OIE’s BSE risk designation.”

“Previously, Russia was the largest export market for U.S. beef livers, and we look forward to rebuilding this market once again,” says Blair. “In 2003, Russia was the fifth largest export market for U.S. beef in terms of quantity, importing over 140 million pounds of U.S. beef and beef variety meats valued at over $53 million.”

“We urge the Russian and U.S. veterinarians to jointly inspect all slaughter facilities applying to export beef to Russia as quickly as possible, so that trade may resume promptly,” says John. “We want Russian consumers to be enjoying our beef for the winter holidays, and going into the New Year.”

President Bush and Russian President Vladimir Putin signed the bilateral trade agreement yesterday as part of Russia's bid for accession to the World Trade Organization (WTO). U.S. cattle producers are in strong support of the full bilateral agreement, which will effectively break down market access barriers to beef by lowering tariffs and raising quota levels for U.S. beef exports.

For more details on this agreement, go to the Office of the U.S. Trade Representative online at: www.ustr.gov .