Agriculture and Greenhouse Gases
Jill Heemstra, University of Nebraska - Lincoln
Building Environmental Leaders in Animal Agriculture (BELAA)
Why Is This Important?
• Agriculture emits greenhouse gases (GHGs)
• Agricultural activities can capture or
sequester GHGs
• Changing climate can impact on-farm
management decisions
• Policy conversations & development will
include agriculture
Building Environmental Leaders in Animal Agriculture (BELAA)
U.S. Greenhouse Gas Emissions
U.S.
EPA
2012
Building Environmental Leaders in Animal Agriculture (BELAA)
Climate Change Policy
©University of Nebraska Institute of Agriculture
and Natural Resources
Building Environmental Leaders in Animal Agriculture (BELAA)
What Do We Need to Know?
•Greenhouse gases (GHGs)
associated with agriculture
• Agricultural activities that
emit GHGs
• Strategies for mitigation &
adaptation
• Opportunities
Building Environmental Leaders in Animal Agriculture (BELAA)
Greenhouse Gases Associated
With Agriculture
• Carbon dioxide - CO2
• Methane - CH4 (21 times the global warming
potential, GWP, as CO2)
• Nitrous oxide - N2O (310 GWP)
When reading about total GHG emissions, the amounts reported
are generally carbon dioxide equivalent (CO2e) which converts
some gases to a higher number to factor in their higher global
warming potential
Building Environmental Leaders in Animal Agriculture (BELAA)
Agriculture Activities
• Nitrous oxide
– Agricultural soil
management (Fertilizer
application & cropping
practices)
– Manure management
Photo courtesy Rick Koelsch, University of Nebraska
– Field Burning of ag residues
Building Environmental Leaders in Animal Agriculture (BELAA)
Agriculture Activities
• Methane
– Enteric fermentation (digestion)
– Manure management
(uncovered manure storage)
– Rice cultivation
– Field burning ag residues
Building Environmental Leaders in Animal Agriculture (BELAA)
Photo courtesy USDA NRCS
Photo courtesy Mark Rice, North Carolina
State University
Agriculture Activities
• Carbon dioxide
– Fossil fuels
– Electricity
Building Environmental Leaders in Animal Agriculture (BELAA)
Carbon Footprint
Carbon footprint: The total amount of
greenhouse gases are emitted into the
atmosphere each year by a person, family,
building, organization, or company,
including emissions from direct sources as
well as indirect sources.
Life Cycle Analysis: A process
to calculate carbon footprint
Building Environmental Leaders in Animal Agriculture (BELAA)
Building Environmental Leaders in Animal Agriculture (BELAA)
Mitigation and Adaptation
Mitigation=reducing GHGs
Adaptation=risk management
Building Environmental Leaders in Animal Agriculture (BELAA)
Farm Management Decisions
Building Environmental Leaders in Animal Agriculture (BELAA)
Adaptation
• Preparation for changes in:
– Temperature
– Frequency of extreme weather events
– Hydrologic cycles and connections (water
quantity)
– Timing of farm operations
– Invasive species (plant and animal)
Building Environmental Leaders in Animal Agriculture (BELAA)
Adaptation Examples
• Extreme rainfall events are
causing more frequent
manure storage spills in
your state. This pattern is
expected to continue.
• How can a farm
manage this risk?
Photos courtesy Kevin Erb, University of Wisconsin
Building Environmental Leaders in Animal Agriculture (BELAA)
Adaptation Examples
• A ranch in an arid or semi-arid environment
is developing a 10 year plan. What climate
influences need to be considered?
Building Environmental Leaders in Animal Agriculture (BELAA)
Animal Ag & Climate Change
Building Environmental Leaders in Animal Agriculture (BELAA)
Mitigating GHG Emissions
•
•
•
•
•
•
Soil carbon sequestration (CO2)
Biofuel production (CO2)
Nitrogen use efficiency (N2O)
Covered manure storage (CH4)
Animal diet (CH4 & some N2O)
Energy efficiency; reducing fuel use (CO2)
Building Environmental Leaders in Animal Agriculture (BELAA)
Agriculture & Sequestration
“Agricultural practices collectively can
make a significant contribution at low cost
to increasing soil carbon sinks, to GHG
emission reductions, and by contributing
biomass feedstocks for energy use”
IPCC Fourth Assessment Report on Climate Change 2007
Building Environmental Leaders in Animal Agriculture (BELAA)
Mitigating GHG Emissions
• Soil carbon sequestration (CO2)
Perennials
Cover Crops
Photo courtesy USDA NRCS
Manure
No-till
Photo courtesy
USDA NRCS
Building Environmental Leaders in Animal Agriculture (BELAA)
Mitigating GHG Emissions
• Biofuel production (CO2)
Algae
Switchgrass
©University of Nebraska Institute of
Agriculture and Natural Resources
©University of Nebraska Institute of
Agriculture and Natural Resources
Building Environmental Leaders in Animal Agriculture (BELAA)
Ethanol plant
Mitigating GHG Emissions
• Nitrogen use efficiency (N2O)
©University of Nebraska Institute of
Agriculture and Natural Resources
Building Environmental Leaders in Animal Agriculture (BELAA)
Mitigating GHG Emissions
• Covered manure storage (CH4)
Photo courtesy Doug Hamilton,
Oklahoma State University
Photo courtesy Rick Stowell, University
of Nebraska
Examples of manure anaerobic digesters
Building Environmental Leaders in Animal Agriculture (BELAA)
Mitigating GHG Emissions
• Animal diets (CH4, N2O)
Photo courtesy Sharon Sakirkin, Texas
AgriLife Extension System
Building Environmental Leaders in Animal Agriculture (BELAA)
Mitigating GHG Emissions
• Energy efficiency; reducing fuel use (CO2)
Photo courtesy Anne Cumbie Randle
Randle Organic Farm, AL
Photo courtesy Mark Risse, University of Georgia
Building Environmental Leaders in Animal Agriculture (BELAA)
Mitigating GHG Emissions
• Trade offs
Building Environmental Leaders in Animal Agriculture (BELAA)
Trade-Offs
• If feeding grain to ruminants results in less
methane emissions, does that mean we
should craft programs that encourage
farmers to feed more
grain and less
forage?
Photo courtesy USDA NRCS
Building Environmental Leaders in Animal Agriculture (BELAA)
Trade-Offs
• If switching to perennial crops can
sequester more carbon in the soil, should
we be converting significant amount of crop
land to perennials?
Building Environmental Leaders in Animal Agriculture (BELAA)
Policy & Mitigation
• 2009 EPA finding of “endangerment”
• Mandatory GHG Reporting Rule
• Cap & trade
• Carbon tax
• State regulations
Building Environmental Leaders in Animal Agriculture (BELAA)
Opportunities
• Reduced input costs
• Carbon payments or renewable energy
credits
• Incentivize BMPs
• Market access/advantage
Building Environmental Leaders in Animal Agriculture (BELAA)
Summary
• Agriculture is a significant source of
methane and nitrous oxide
• Many current recommended management
practices also mitigate GHGs
• Production efficiency is key
Building Environmental Leaders in Animal Agriculture (BELAA)
Summary
• Farm and ranch business plans should
consider and prepare for:
– Ways to adapt to changing climate
– Financial opportunities
– Possibility of regulations
Photo courtesy USDA NRCS
Building Environmental Leaders in Animal Agriculture (BELAA)
Contact Information
• Jill Heemstra:
–jheemstra@unl.edu
Building Environmental Leaders in Animal Agriculture (BELAA)