Turfgrass is a Positive Sequester of Carbon

February 17th, 2010Filed under EnvironmentOutdoor Power Equipment Institute Seeks Correction and Public Disclosure of
Significant Computation Error in AGU and UC-Irvine’s Recently Released Urban
Turf Report; Correction Shows

Alexandria, VA – February 15, 2010 – The  Outdoor
Power Equipment Institute (OPEI) today announced that Dr. Amy Townsend-Small
of University of California – Irvine (UC – Irvine) acknowledged a
computation error of carbon used to maintain turf in the recently released
UC-Irvine study published January 19, 2010, titled “Carbon Sequestration and
Greenhouse Gas Emissions in Urban Turf.”  With the error corrected,
ornamental grass is in fact shown to be a net sequester of carbon even when
inputs are accounted for in grass maintenance.  The correction has been
submitted to the American Geophysical Union (AGU) who published the paper.

Upon review of the report, various flaws were discovered, including one
significant math error that was made in computing the carbon consumed during
mowing.  The carbon from fuel consumption was multiplied by 12, one too many
times, to convert from monthly to annual data.  The error was not caught
during the peer review process prior to publication of the paper by the AGU.
When the computation is corrected, turfgrass actually is a net sequesterer
of carbon dioxide, reversing the conclusions of the original report that was
widely reported in the media.

“Blaming grass for contributing to global warming is a non-starter when you
look at the facts.  The grass in your backyard is working hard to keep us
cool, soak up carbon, capture particulates, produce oxygen, capture rain
water and reduce run-off.  We need to focus on the right plant in the right
place and on management practices that maximize the environmental benefits
potential of turfgrass,” said Kris Kiser, Executive Vice President of OPEI.

Kiser added that, “While the UC-Irvine study, rightly so, highlights that
mismanagement of turfgrass can occur via excessive fertilization and
irrigation, and inefficient maintenance practices, the focus should be on
proper management techniques.”  OPEI stressed that proper management
techniques can minimize carbon emissions and maximize the benefits of carbon
sequestration in turfgrass; for example, proper selection of turf based on
climatic region (drought resistant species) and leaving grass clippings on
the grass to serve as a natural nitrogen fertilizer.

OPEI also noted that the UC-Irvine study did not acknowledge the dramatic
reductions of emissions and fuel use profile for today’s gasoline and diesel
equipment, nor did the study disclose what model equipment and corresponding
fuel use numbers were used.

Mowers and outdoor power equipment today are the cleanest in history and
fully regulated by the U.S. EPA and California’s Air Resources Board since
1997.   EPA Phase 3 and CA Tier 3 compliant product are 90 percent cleaner
than pre 1997 models. Coupled with improvements in emissions, there have
been substantial improvements in mower fuel efficiency.  Additionally,
outdoor power equipment manufacturers have introduced a number of electric,
battery, biodiesel, gasoline-electric and diesel-electric hybrids, propane,
CNG, solar and other alternative fueled products with corresponding
reductions  in carbon output.

Other issues found with the UC-Irvine urban turf study:

.         The paper uses a technique (passive flux chambers) that is often
inaccurate in measuring surface flux because it is not clear that what is
being measured is at equilibrium.

.         The UC-Irvine study focused on one urban center in Southern
California.  Management techniques across the country are variable and
therefore, can’t be applied broadly. Future studies should look at sites in
other parts of the country.

.         The UC-Irvine study did not measure actual inputs of water and
nutrition but made estimates based upon standards or agriculture averages.
Future studies should measure actual inputs or use the best available
technology to estimate inputs of water and fertilization.

To learn more about the carbon sequestration benefits of turfgrass, see the
paper, Technical Assessment
  of the Carbon
Sequestration Potential of Managed Turfgrass in the United States by Dr. Ron
Sahu.

About the Outdoor Power Equipment Institute

OPEI is an international trade association representing the $15 billion
landscape, forestry, utility and lawn and garden equipment manufacturing
industry. OPEI is a recognized Standards Development Organization for the
American National Standards Institute (ANSI) and active internationally
through the International Standards Organization (ISO) in the development of
safety standards. Founded in 1952, OPEI represents and promotes the outdoor
power equipment industry before federal, state and international legislative
and regulatory bodies. For more information on OPEI, visit
www.OPEI.org.

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Kris Kiser

Executive Vice President

Outdoor Power Equipment Institute

(703) 549-7600

KKiser

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