Agriculture Reference
In-Depth Information
9
Air Quality Issues in Sustainability:
Greenhouse Gases and Volatile
Organic Compounds
S.E. Place
1
and F.M. Mitloehner
2
*
1
Department of Animal Science, Oklahoma State University,
Stillwater, Oklahoma, USA;
2
Department of Animal Science,
University of California, Davis, California, USA
Introduction
as any carbon-containing compound that par-
ticipates in atmospheric photochemical reac-
tions, excluding carbon monoxide, CO
2
, carbonic
acids, metallic carbides or carbonates (EPA, 2011).
These gases are important air pollutants because
they contribute to the formation of ground-level
ozone (Carter, 1994). This chapter will present
a thorough discussion of the sources of GHG
and VOC emissions from animal agriculture
and potential emission mitigation techniques.
Animal agriculture production systems (beef,
dairy, pork, etc.) play a critical role in the US food
system, the economy, land use and nutrient
cycling. Therefore, a thorough discussion of ani-
mal agriculture's sustainability requires exami-
nation of environmental, societal and economic
components of sustainability. Within the envi-
ronmental component, one area of interest is
the carbonaceous and nitrogenous gaseous
emissions that arise from animal agriculture
production. For the purposes of this chapter, two
broad classes of gaseous emissions will be dis-
cussed: greenhouse gas (GHG) emissions and
volatile organic compounds (VOCs). Emissions
of GHG are important to the discussion of sus-
tainability because these gases contribute to
climate change via their ability to absorb infra-
red radiation emanating from the surface of the
Earth and emit radiation back towards the
Earth's crust (Seinfeld and Pandis, 2006).
The major GHG emissions from animal agricul-
ture are carbon dioxide (CO
2
), methane (CH
4
) and
nitrous oxide (N
2
O).
VOCs are a class of compounds that include
thousands of gases and the US EPA defines VOCs
Sources of GHG and VOC Emissions
from Animal Production
Greenhouse gases
GHGs include CO
2
, N
2
O, CH
4
, water vapour and
chlorofluorocarbons among others, and have
the ability to absorb long-wave infrared radia-
tion emanating from the Earth's crust and emit
radiation back towards the surface of the Earth
(Seinfeld and Pandis, 2006). As a result, GHGs
play an important role in maintaining the global
average temperature within a range that is con-
ducive to life. It is estimated that without the
