Agriculture and Greenhouse Gases Jill Heemstra, University of Nebraska - Lincoln Building Environmental Leaders in Animal Agriculture (BELAA)

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

U.S. Greenhouse Gas Emissions


U.S. EPA 2012

Climate Change Policy


©University of Nebraska Institute of Agriculture and Natural Resources

What Do We Need to Know?


•Greenhouse gases (GHGs) associated with agriculture• Agricultural activities that emit GHGs• Strategies for mitigation & adaptation• Opportunities

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


Agriculture Activities


• Nitrous oxide– Agricultural soil management

(Fertilizer application & cropping practices)

– Manure management

– Field Burning of ag residuesPhoto courtesy Rick Koelsch, University of Nebraska



• Methane– Enteric fermentation (digestion)– Manure management

(uncovered manure storage)

– Rice cultivation– Field burning ag residues

Photo courtesy USDA NRCS

Photo courtesy Mark Rice, North Carolina State University



• Carbon dioxide– Fossil fuels– Electricity

Carbon FootprintCarbon 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



Mitigation and Adaptation

Mitigation=reducing GHGs

Adaptation=risk management


Farm Management Decisions


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)


Adaptation Examples• Extreme rainfall events are

causing more frequent manure storage spills in your state. This pattern isexpected to continue.

• How can a farmmanage this risk?


Photos courtesy Kevin Erb, University of Wisconsin

Adaptation Examples• A ranch in an arid or semi-arid environment

is developing a 10 year plan. What climate influences need to be considered?


Animal Ag & Climate Change


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)


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

Mitigating GHG Emissions• Soil carbon sequestration (CO2)


No-till

Perennials

Cover Crops

Manure



Mitigating GHG Emissions• Biofuel production (CO2)




Algae

SwitchgrassEthanol plant

Mitigating GHG Emissions• Nitrogen use efficiency (N2O)



Mitigating GHG Emissions• Covered manure storage (CH4)


Examples of manure anaerobic digesters

Photo courtesy Doug Hamilton, Oklahoma State University

Photo courtesy Rick Stowell, University of Nebraska

Mitigating GHG Emissions• Animal diets (CH4, N2O)


Photo courtesy Sharon Sakirkin, Texas AgriLife Extension System

Mitigating GHG Emissions• Energy efficiency; reducing fuel use (CO2)


Photo courtesy Anne Cumbie RandleRandle Organic Farm, AL

Photo courtesy Mark Risse, University of Georgia

Mitigating GHG Emissions• Trade offs


Trade-Offs• If feeding grain to ruminants results in less

methane emissions, does that mean we should craft programs that encourage farmers to feed moregrain and lessforage?



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?


Policy & Mitigation


• 2009 EPA finding of “endangerment”• Mandatory GHG Reporting Rule

• Cap & trade• Carbon tax• State regulations

Opportunities• Reduced input costs• Carbon payments or renewable energy

credits• Incentivize BMPs• Market access/advantage


Summary• Agriculture is a significant source of

methane and nitrous oxide• Many current recommended management

practices also mitigate GHGs• Production efficiency is key


Summary• Farm and ranch business plans should

consider and prepare for:– Ways to adapt to changing climate– Financial opportunities– Possibility of regulations



Contact Information


• Jill Heemstra: – [email protected]

mailto:[email protected]

Documents

Agriculture and Greenhouse Gases Jill Heemstra, University of Nebraska - Lincoln Building Environmental Leaders in Animal Agriculture (BELAA)