Raising a global
stink
Activists target methane gas from, um, cows
By Michael Hawthorne | Chicago Tribune reporter
11:38 PM CDT, July 30, 2008
Burgeoning efforts to curb global-warming pollution are
taking aim at an unlikely new target: the placid, cud-chewing cow.
Scientists have long known that cattle and other livestock
are a major contributor to climate change worldwide, and although researchers,
regulators and activists have devoted most of their attention to other
culprits—such as cars and coal-fired power plants—that is starting to change.
As dairy and beef cows chew and rechew
their feed, their belches and other, er, gastric
eruptions produce enormous quantities of methane, a greenhouse gas 23 times
more potent than carbon dioxide.
All that cow flatulence is bad enough, but clearing forests
for pastures and the manufacturing of fertilizers to grow cattle feed produce
even more greenhouse gases. When those sources are
considered, the United Nations estimates that the world's livestock system is a
bigger part of the problem than transportation.
The impact is great enough that researchers are stepping up
efforts to limit bovine burps by tinkering with cattle feed. Some large
dairies, including three in Illinois, are pumping the millions of gallons of
manure they produce into bacteria-filled tanks that capture methane and use it
to generate electricity.
Changes are quietly taking place at supermarkets and dinner
tables, too. Bon Appetit Management Co., which
operates 400 cafes at universities, museums and corporate offices in the
One of the company's three local cafeterias, at
"People still don't get the impact of food as a
significant contributor to climate change or the environment in general,"
said Helene York, who directs Bon Appetit's Low
Carbon Diet. "But there are ways big and small that we can change the
culture."
More carbon-efficient management of livestock, manure and
food production almost assuredly will be required if Congress moves next year
to reduce the nation's contributions to climate change.
Methane is a big concern because it is so much more potent
than carbon dioxide, the chief source of man-made pollution behind rising
global temperatures. So is nitrous oxide, another byproduct of manure and
fertilizer production. It has a whopping 296 times the heat-trapping potential
of carbon dioxide.
Domestic cattle packed into feedlots and dairies might seem
like an unlikely part of the problem. But because ruminants eat enormous
amounts of hay, corn and other feed, then belch it up again and again as they
chew their cud, a single cow can produce up to 400 pounds of methane a year.
The manure is a malodorous mess that churns even more
methane into the air. All told, the U.S. Environmental Protection Agency
estimates that livestock burps, flatulence and waste accounts for more than a
quarter of the nation's methane emissions, second only to decomposing garbage
in landfills.
In the rolling hills of northwest
When the brothers decided a few years ago to expand their
Cow power, as the Blocks call it, provides about a third of
the dairy's electricity. It also makes the brothers money through the Chicago
Climate Exchange, a voluntary network of corporations and governments that
trades credits for greenhouse gas emissions, similar to the way milk and beef
futures are bought and sold.
By keeping methane out of the atmosphere, the dairy farmers
get to sell carbon credits to companies that fail to meet their pledges to
reduce global warming pollution. The arrangement recently netted the Blocks a
$24,000 check, and has turned the former climate-change skeptics into true
believers.
"We're greedy dairy farmers, but as we got into this we
started to understand how what happens on the farm can help solve a big
problem," Doug Block said. "These carbon credits are an encouragement
for people and companies to do the right thing."
Another possible solution to the world's methane problems is
emerging from university laboratories. In recent years researchers have tried
to come up with feed additives that cut down on cow belches—and emissions from
the other end of the animal.
A group of Japanese scientists reported this year that they
had happened upon a methane-reducing formula of nitrates and cysteine, an amino acid. In
Lab experiments show some promise in lowering methane
concentrations in cow stomachs and boosting the amount of other compounds that
give the animals energy. But it's unclear if and when any of the additives
might move to the barn.
"This hasn't been a big issue until now," said
Frank Mitloehner, director of the
Farmers and agricultural researchers also can help, Mitloehner said, by improving the health and productivity
of dairy cattle so they don't need to be replaced as frequently. Raising
back-up herds creates more greenhouse gases.
"I think we can get there," Mitloehner
said. "We just need to change the way of thinking in the agricultural
community."
Changes are happening at the other end of the
food-production line. Hardly a week goes by without an announcement by one of
the nation's food service companies or grocery chains that it is embracing
greener practices such as energy efficiency and waste reduction.
At the
The average American meat-oriented diet produces 3,000 more
pounds of carbon dioxide each year than a calorie-equivalent vegan, or plant-based,
diet, according to a 2006 University of Chicago study. Opting for chicken
instead of beef saves about 2,250 pounds.
"We're here to educate and provide more choices,"
said Amy Audiffred, the cafeteria's general manager.
"It turns out you can do a million delicious things with food and reduce
your carbon footprint at the same time."
Making changes hasn't hurt the cafeteria's image. A
Princeton Review student survey released this week named it No. 1 among
colleges for best food.
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