Agriculture and Greenhouse Gas Emissions
•Descargar como PPT, PDF•
6 recomendaciones•6,806 vistas
How does agriculture, especially animal agriculture, impact greenhouse gas emissions? What is adaptation and mitigation and how are these different? For more materials on this topic visit http://www.extension.org/pages/63908/greenhouse-gases-and-animal-agriculture
Recomendados
Recomendados
Más contenido relacionado
La actualidad más candente
La actualidad más candente (20)
Similar a Agriculture and Greenhouse Gas Emissions
Similar a Agriculture and Greenhouse Gas Emissions (20)
Más de LPE Learning Center
Más de LPE Learning Center (20)
Último
Último (20)
Agriculture and Greenhouse Gas Emissions
- 1. Agriculture and Greenhouse Gases Jill Heemstra, University of Nebraska - Lincoln Building Environmental Leaders in Animal Agriculture (BELAA)
- 2. 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)
- 3. U.S. Greenhouse Gas Emissions U.S. EPA 2012 Building Environmental Leaders in Animal Agriculture (BELAA)
- 4. Climate Change Policy ©University of Nebraska Institute of Agriculture and Natural Resources Building Environmental Leaders in Animal Agriculture (BELAA)
- 5. 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)
- 6. 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)
- 7. 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)
- 8. Agriculture Activities • Methane – Enteric fermentation (digestion) – Manure management (uncovered manure storage) Photo courtesy USDA NRCS – Rice cultivation – Field burning ag residues Photo courtesy Mark Rice, North Carolina State University Building Environmental Leaders in Animal Agriculture (BELAA)
- 9. Agriculture Activities • Carbon dioxide – Fossil fuels – Electricity Building Environmental Leaders in Animal Agriculture (BELAA)
- 10. 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)
- 11. Building Environmental Leaders in Animal Agriculture (BELAA)
- 12. Mitigation and Adaptation Mitigation=reducing GHGs Adaptation=risk management Building Environmental Leaders in Animal Agriculture (BELAA)
- 13. Farm Management Decisions Building Environmental Leaders in Animal Agriculture (BELAA)
- 14. 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)
- 15. 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)
- 16. 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)
- 17. Animal Ag & Climate Change Building Environmental Leaders in Animal Agriculture (BELAA)
- 18. 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)
- 19. 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)
- 20. 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)
- 21. Mitigating GHG Emissions • Biofuel production (CO2) Algae Ethanol plant 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)
- 22. Mitigating GHG Emissions • Nitrogen use efficiency (N2O) ©University of Nebraska Institute of Agriculture and Natural Resources Building Environmental Leaders in Animal Agriculture (BELAA)
- 23. 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)
- 24. Mitigating GHG Emissions • Animal diets (CH4, N2O) Photo courtesy Sharon Sakirkin, Texas AgriLife Extension System Building Environmental Leaders in Animal Agriculture (BELAA)
- 25. Mitigating GHG Emissions • Energy efficiency; reducing fuel use (CO2) Photo courtesy Anne Cumbie Randle Photo courtesy Mark Risse, University of Georgia Randle Organic Farm, AL Building Environmental Leaders in Animal Agriculture (BELAA)
- 26. Mitigating GHG Emissions • Trade offs Building Environmental Leaders in Animal Agriculture (BELAA)
- 27. 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)
- 28. 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)
- 29. Policy & Mitigation • 2009 EPA finding of “endangerment” • Mandatory GHG Reporting Rule • Cap & trade • Carbon tax • State regulations Building Environmental Leaders in Animal Agriculture (BELAA)
- 30. Opportunities • Reduced input costs • Carbon payments or renewable energy credits • Incentivize BMPs • Market access/advantage Building Environmental Leaders in Animal Agriculture (BELAA)
- 31. 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)
- 32. 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)
- 33. Contact Information • Jill Heemstra: – jheemstra@unl.edu Building Environmental Leaders in Animal Agriculture (BELAA)
Notas del editor
- Instructional notes will be in italics throughout this presentation. These italicized portions are for reference only and are not meant to be part of the “script” . Throughout the notes section of this presentation, you will see “farm/ranch” or “farmer/rancher”. Since it is awkward to say “farm or ranch” throughout a presentation, you are encouraged to select one term or the other as best fits your audience and simply ignore the references to the other term. Greenhouse gas concentrations in our atmosphere have increased dramatically since the Industrial Revolution. This increase has been the source of concern among scientists and many in the general public. Greenhouse gases play a role in absorbing and trapping heat in the atmosphere making them an important factor driving global climate. Because of the link between greenhouse gases and climate, a discussion on the increase in these gases is generally termed “climate change”. While climate change has become a politically-charged issue and many disagree on the ways to move forward with policy and solutions, it is clear that climate change will continue to receive a great deal of attention. Let us take a moment for a bit of perspective: Greenhouse gases (GHGs) are not “bad”. Without GHGs, our planet’s average temperature would be around 0 degrees Fahrenheit instead of our current average which is around 57 degrees F). (Source: http://www.ncdc.noaa.gov/oa/climate/globalwarming.html) . However, even seemingly small changes in the concentration of these gases can have impacts on global climate and weather patterns. The main reason that this topic has been elevated to everyday conversation is because of how quickly the levels have risen over the past 150-200 years. The predictions put forward by climate scientists continue to be refined and improved, but most indications are that we need to prepare for a hotter and more extreme climate. Note: This presentation is not meant to advocate for any particular policy or political agenda. It focuses largely on two practical aspects of this topic: Future ag professionals need to be prepared to evaluate the likelihood of various climate scenarios and make long-term management decisions on farms, ranches, or agribusinesses based on the best information they have available at the time. As policy discussions and development continue, agriculture professionals need to stay involved and informed in order to advocate for sound policy decisions.
- There are four points to consider when asking yourself “Why should I care about this topic?”. The first two seem obvious. Agriculture is a source of greenhouse gases, but, as an industry, it also has a great deal of potential for mitigating the release of greenhouse gases to the atmosphere. The 3 rd point is a very practical one in that changes in climate can impact decisions that a farmer, rancher, or agribusiness owner will make. Last, but not least, is the fact that any future policy conversations or development are going to inevitably include or somehow impact agriculture.
- #1. Agriculture is an economic sector that emits greenhouse gases This graph is taken from the 2012 EPA Greenhouse Gas Inventory (which included data through the year 2010). It summarizes the major U.S. economic sectors and the allocation of all U.S. greenhouse gas emissions to each of these economic sectors. Agriculture accounts for between 7-8% of U.S. emissions. Industry’s share is 30% with transportation accounting for 27%. The commercial and residential sectors are around 18% and 17% each, respectively. This graph distributes electricity to each sector according to its use. As an interesting comparison, agriculture on a worldwide basis is estimated to be the source of 10-12% of anthropogenic greenhouse gas emissions (2007 Intergovernmental Panel on Climate Change http://ipcc.ch/publications_and_data/ar4/wg3/en/ch8s8-3.html --electricity is not part of this total. If you remove electricity from agriculture in the EPA graph above it would account for around 7% of US GHG emissions). U.S. agriculture emissions (as a % of overall anthropogenic or man-made emissions) is a smaller % than worldwide agriculture. A couple of reasons usually given for this is that U.S. agriculture is not actively deforesting land for crop or feed production. A second reason given is that U.S. agriculture is highly efficient compared to many other agricultural systems worldwide and produces a high amount of product in comparison to the inputs consumed. Even though agriculture is the lowest line on this graph, this does not mean that agriculture is insignificant when it comes to emissions. As you will see in some graphs later in the presentation, there are categories where agriculture is a leading source of man-made emissions. This graph includes fossil fuel and electricity use on farms in the calculations. Other graphs and data (within the same EPA report) treat energy and fossil fuel use differently. In some sections, the electricity and fossil fuel use on farms is not calculated as part of agriculture but is instead considered part of the “energy” or “electricity generation” sectors. Both reporting methods are valid, but it is important to recognize which area of the report you are reading and how they break out energy use before making comparisons.
- Policy conversations and development will include agriculture. These photos depict the United State Capitol as well as a state capitol building. Climate change is a policy topic at both the state and federal level. The current political landscape is filled with disagreement, and climate change has become especially contentious. Regardless of your individual opinions or views about this issue, it is extremely important that farmers, ranchers, and other agriculture professionals stay informed about the science, and engage with organizations, law makers, and the general public. Any policies that are developed will almost certainly have impacts on agriculture. Whether those impacts are positive or negative (or a mixture) will depend on farmers, ranchers, ag professionals and those with a direct knowledge of farming and ranching being involved and advocating for sound, science-based decisions.
- So, what do we need to know about this topic? The first slides will look at which greenhouse gases (GHG) are emitted by agriculture. This is closely tied to the second topic in which we will discuss the ag activities that result in GHG emissions. We will also look at strategies agriculture can use to reduce (or mitigate) the amount of GHGs they produce as well as areas where agriculture should be prepared to adapt to changes that will come with climate change. Lastly, we will look at the opportunities that could be available to ag producers. The photo on the right shows a field where feed feedlot manure was applied to a small grain field after harvest. This exemplifies the balancing act that agriculture will experience. On one hand, manure management and even land application of manure results in greenhouse gas emissions. On the other, manure application to fields is a good way to add carbon to soils—an area where we can “sink” or store carbon and effectively remove it from the atmosphere.
- There are three greenhouse gases (GHGs) that are most mentioned when discussing agriculture and greenhouse gases. These are carbon dioxide (CO2), methane (CH4), and Nitrous oxide (N2O). Carbon dioxide is the gas that most people talk about and makes up more than 80% of GHGs emitted as a result of human activities. However, CO2 is a distant 3 rd place when discussing greenhouse gases important to agriculture. The two gases that farmers and ranchers should be aware of are methane and nitrous oxide. Methane is especially associated with livestock. More than one-fourth of the total of methane resulting from human activities (Source: 2011 EPA Greenhouse Gas Inventory) is from animal agriculture. Nitrous oxide is a major emission, especially from agricultural soil management (cropping systems). These emissions largely result from fertilizer and, to a lesser extent, manure storage and application on cropland. When talking about the potential impacts, not all greenhouse gases are created equal. To compare them scientists have developed a measurement that standardizes the potential global warming potential of a gas relative to carbon dioxide. In this scale, carbon dioxide is a relative score of 1, because it is being compared to itself. A pound of methane has 21 times the impact of a pound of carbon dioxide. Nitrous oxide has a GWP of 310. This means that a pound of nitrous oxide has the same impact as releasing 310 pounds of carbon dioxide into the atmosphere.
- The largest source of agricultural nitrous oxide is, by far, agricultural soil management. “Soil management” refers to fertilizer applications and cropping activities like tillage, planting or other actions that directly disturb soil. It does not include land use changes such as converting pasture to crop land or vice versa. If you remember back to previous slides, nitrous oxide is very potent, over 300 times more powerful than carbon dioxide at trapping heat in the atmosphere. This means that even small amounts of nitrous oxide emissions are a big concern for climate change. The next largest agricultural source of nitrous oxide is manure management. Nitrous oxide is released in small quantities from manure storage structures. Field burning of ag residues is measurable and therefore included in the EPA greenhouse gas inventory, but is a minor source of emissions compared to the other two on this slide. For additional information about nitrous oxide and manure see: http://www.extension.org/pages/23296/air-emissions-after-manure-land-application-including-subsurface-application-of-poultry-litter-and-so (Watch the first Curtis Dell presentation “Gaseous Emissions Following Land Application of Manures”)
- The most significant greenhouse gas emitted from animal agriculture is methane. Most of this agricultural methane comes from digestion of feed by ruminant animals such as beef or dairy cattle, sheep or goats. After an animal consumes feed, the natural process of fermentation by microbes in the rumen or gut produces methane. This methane is released to the atmosphere when animals belch and, well….emit gases in other ways. Enteric fermentation is estimated to be 71% of all agricultural methane emissions and 20% of all methane produced as a result of all human activities (Source: US EPA Greenhouse Gas Inventory 2011). Some methane is produced by pigs or chickens, but this is a very small fraction of the amount produced by ruminants. Manure management is also a greenhouse gas, mostly methane, source. Manure is responsible for ~25% of agricultural methane emissions and 7% of the total methane from human activities (Source: US EPA Greenhouse Gas Inventory 2011). The term “manure management” refers to the practice of collecting and storing manure in a contained area until conditions are right for land application. As the manure in these storage structures decomposes (under anaerobic, or “without oxygen” conditions), it releases methane. Unless the structure is enclosed with an engineered cover, this methane escapes to the atmosphere. This is especially true of livestock systems that use liquid or slurry manure storages which are usually swine and dairy operations. The next two, much smaller, sources of methane from agriculture are rice cultivation (3.7% of ag methane emissions) and field burning of ag residues. In rice cultivation, methane results from the flooded soils. In these anaerobic (without oxygen) conditions, soil organic matter is decomposed, releasing a small amount of methane. Field burning of ag residues (0.1% of ag methane emissions) is sometimes practiced when producing sugarcane, turfgrass seed, warm season range/pasture, or other areas where excessive crop residues can hinder future plant growth or harbor weeds or diseases.
- When compared to the other sources of agricultural emissions, the use of fuels and electricity on farms is a small piece of the greenhouse gas emissions. One exception to this is on poultry farms. Since poultry production generally uses solid or dry manure systems (which emit less methane than liquid systems) and chickens do not emit much methane due to enteric fermentation, fuel and electricity are responsible for the majority of greenhouse gases on poultry farms (Source: http://www.caes.uga.edu/publications/pubDetail.cfm?pk_id=7939). Note to teachers: Some people talk about animal respiration as a source of greenhouse gas emissions. The CO2 released in respiration is balanced by the CO2 uptake of the plants they eat. Respiration is generally considered carbon neutral.
- Now that we have discussed the types of greenhouse gases and agricultural activities that emit them, the next step is to put that together. When you calculate the total amount of greenhouse gases (not just carbon dioxide, but also methane, nitrous oxide, and others) emitted by an entity, that is called a carbon footprint. A carbon footprint is the total amount of greenhouse gases that are emitted into the atmosphere each year by a person, family, building, organization, or company. This includes direct emissions as well as indirect ones. This footprint accumulates throughout each stage of the production process. What is a direct emission? Just as the name implies, those are gases produced as a direct result of your activities. On a livestock farm, some direct emissions will be the methane emitted by the animals themselves or the manure storage. It would also include fuel burned in tractors, a feed truck, heating, etc. Some indirect emissions on a livestock farm would be those released while raising corn or other feeds as well as the emissions from manufacturing tractors, combines and planters as well as fencing materials, building materials, or cement. The way that you calculate a carbon footprint is by doing a life cycle analysis (LCA). An LCA is a way to carefully outline what is included in the carbon footprint and what is not. Different organizations have published standards that can be used when conducting an LCA. Those who use the same LCA process when comparing their own carbon footprint over time or comparing to another product or company can have a high degree of confidence in those comparisons. When you read news articles or see product claims, it is important to find out if the comparisons are being made using apples and apples. One example is the 2006 report from the United National Food and Agriculture Organization called “Livestock’s Long Shadow” (http://www.fao.org/docrep/010/a0701e/a0701e00.HTM). This report compared worldwide emissions sources and concluded that livestock were responsible for 18% of the world’s emissions—even more than transportation. After analyzing the report, a University of California scientist (http://create.extension.org/sites/default/files/UC%20Davis%20News%20%26%20Information%20__%20Don%E2%80%99t%20Blame%20Cows%20for%20Climate%20Change.pdf) found that the numbers used for livestock included a complete life cycle analysis, but that the transport numbers only included direct emissions from burning fuels. The idea that livestock generated more greenhouse gases received a great deal of attention and is still frequently quoted by many. If more care had been taken to ensure the comparison was done using truly comparable numbers, much negative publicity for animal agriculture could have been avoided.
- It is important to recognize that this issue is here to stay. Climate change will affect how producers manage their farms, how agribusinesses provide products and services, how regulators and policy makers create rules, and how consumer make buying decisions. Click on the video to start playback. The video is also available for download or online play at: http://youtu.be/B0ILn_23MLo The global warming potential referenced by Dr. Capper in this video lists he GWP of methane as 23 and the GWP of nitrous oxide as 296. This is due to slight differences in how GWP can be calculated. The numbers shown earlier in this slide are from the U.S. EPA and Dr. Capper’s numbers come from the Intergovenmental Panel on Climate Change (IPCC). These differences are relatively minor --the most important point is that not all greenhouse gases are equal in terms of ability to trap heat in the atmosphere.
- Now that we have discussed the gases emitted by agriculture and the activities that are responsible for those emissions, we are going to discuss the two ways that we can address these emissions. One is mitigation and the other is adaptation. Mitigation is used in a broad sense in this presentation. It refers to actions taken to reduce the amount of greenhouse gases that you emit, or to practices that capture or sequester carbon from the atmosphere. Mitigation is generally where most of the controversy occurs as people disagree on the need for mitigation, the urgency, and how to persuade people to change habits in ways that reduce or capture greenhouse gas emissions. Adaption is a pragmatic and practical way of considering this issue. This is essentially a form of risk management in that a farmer, rancher or agribusiness owner looks at different scenarios and evaluates the likelihood of those scenarios occurring. That likelihood, combined with the potential loss you experience if it does occur, will determine if you take action to address that risk or not. Examples of mitigation and adaptation strategies will follow in the next few slides.
- Changing climate can impact on-farm management decisions This photo shows an example of how things change over time. In the front, there is a small two-cylinder tractor hooked to a manure spreader whose capacity is measured in bushels. In the back is a four wheel-drive tractor hooked to a huge manure tanker whose capacity is measured in 1000’s of gallons. Climate scientists continue to study and refine models that are being used to predict the impacts of increased greenhouse gases. The predicted changes have some real and practical implications for farm management decisions such as design or size of buildings, choices in field equipment, selection of animal breeds or crop hybrids, and irrigation management.
- No matter your political stance on the causes, the evidence of climate change is here. With the current political climate surrounding mitigation options being very contentious, more and more talk is about the need for adaptation to the changes predicted to come as a result of increased greenhouse gas concentrations in the atmosphere. This is a practical issue that can directly affect management decisions made on farms. As with any other form of risk management, a farmer or rancher needs to evaluate the likelihood a scenario will occur. That needs to be weighed against the size of the potential loss if it does. For example, a scenario might be very likely, but if it will not lead to significant losses, then a farmer/rancher might not make changes in this area. Another scenario might not be very likely, but if it could have devastating impacts on the farm/ranch, then the prudent manager will look into appropriate plans, insurance, equipment, or other ways to minimize or avoid that situation. -How could these changes impact things like crop rotation? Choice in crops or hybrids? Animal comfort? The next three slides discuss the issue of adaptation further.
- These photos depict manure spills. The first is a staged demonstration in Wisconsin to train manure applicators on cleanup procedures. The bottom photo shows a manure storage structure that failed on a farm and resulted in a spill that covered 4-5 acres of a nearby field. Consider this scenario: -Your state regulations require that manure storage is large enough to hold 180 days of manure production. Your state also requires that manure storage lagoons be inspected regularly, daily rainfall amounts need to be recorded and a plan developed for what they will do in case a manure storage structure fails or appears close to failure. In the past year, two farms in your state have experienced manure storage spills due to extreme rainfall events which resulted in a great deal of negative publicity. The year before that, there were three similar examples. Climatologists predict that these extreme rainfall events are likely to continue. What are some ways a livestock farm can manage this risk? --Should they build a larger manure storage structure than required? (these structures can be very expensive) --Are they willing to devote the time to careful inspections and actually rehearsing and updating their emergency plan rather than just going through the motions? --Would they consider completely changing their production system to one that requires less manure storage? One example would be moving from a confinement system to a pasture or grazing based system. Another would be moving cattle from an open feedlot to a barn that uses large amounts of bedding to completely absorb and contain all manure as solids without any liquid manure storage. (This requires an operator to develop a whole new set of management skills and probably replace or retrofit equipment and buildings) --What if the farm is located upstream from a popular state park? Would that change your answers? --Would your answer to this question be different for a new farm that has not built their manure storage yet versus an established farm that already has a manure storage built? There are no right or wrong answers—the point of this exercise is to discuss the pros and cons of various options. Every farm or ranch will need to evaluate their risks, their strengths and interests to find the best solution.
- For a ranch that is dependent on forages, there are many things that can influence their preparations for the future. Discussion points (if needed): --If this ranch is in a region predicted to have hotter, drier weather should they consider irrigation? (expensive, is water even accessible?) --What if the mix of grasses and forbs begins to shift? How will they notice? How could that affect their grazing system (timing, carrying capacity, more paddocks, less paddocks)? --Should they consider shifting animal genetics? (red hair coats instead of black, different breeds, size of the animal) --Will animals have adequate access to water? Should new or different watering points be developed? --Will current control methods work on new invasive species (plant or animal)? --Are we prepared for extreme weather events like blizzards or floods? How will we handle winter feeding (will animals be able to graze more days each year?) There are no right or wrong answers—the point of this exercise is to discuss the pros and cons of various options. Every farm or ranch will need to evaluate their risks, their strengths and interests to find the best solution.
- The emphasis of this video is two fold: Methane is the area where animal agriculture has the most contribution to greenhouse gas emissions Not only does animal ag need to consider its emissions, but should also consider/study the impacts that changing climate will have on management decisions Click on the video to begin playback. This video is available for download or online play at: http://www.youtube.com/watch?v=dC0WRiefRNc
- There are many ways to mitigate or reduce agriculture’s greenhouse gas emissions. These are listed loosely in order of potential (with the items near the top of the list having the potential for the largest mitigation) using the author’s best judgment based on review of several information sources. Arguments can be made for changing the order between items that are listed directly above or below each other, but overall the items toward the top of the list are going to have more potential to capture or mitigate greenhouse gases than those at the bottom. Starting at the top, we see soil carbon sequestration with a “CO2” in parentheses. The CO2 means that building soil carbon (or organic matter) levels is expected to mostly impact carbon dioxide emissions. Next on the list you see biofuel production, which is also related to carbon dioxide reductions. Next on the list is nitrogen use efficiency, which is directly related to nitrous oxide production (remember from an earlier slide that agricultural soil management is the largest source of ag greenhouse gases). This basically refers to the efficiency with which applied fertilizers are utilized by plants for their growth. Nitrogen applied in excess of plant needs has the potential to be converted to and released as nitrous oxide. After that, we have some methane or CH4-related mitigation strategies. One is to cover manure storage structures. The feed consumed by animals also affects their greenhouse gas emissions, especially methane. Last, we see energy efficiency and reducing fuel use on this list. Just because some items are toward the bottom of list, they should not be regarded as unimportant. For example, reducing fuel or energy consumption can usually be done quickly and at a fairly low cost. Even though it might have a relatively small impact, an easy and economical strategy like that will be an important part of future efforts.
- #2. Agricultural activities can capture or sequester greenhouse gases This quote, from the 2007 report released by the United National Intergovernmental Panel on Climate Change (IPCC) summarizes their review of worldwide scientific literature. The panel singled out increasing soil carbon as the most promising method for agriculture to sequester carbon. It is also interesting to note the phrase “low cost” in the quote. Many of the practices that are currently being researched as ways to capture more carbon in agricultural systems also have some systematic financial benefits to farmers/ranchers. For example, reduced tillage or precision agriculture. We will talk about these and other mitigation strategies later in the presentation. Note to teachers: The IPCC is already finalizing their 5 th assessment report on climate change, expected to be released in 2013. You can visit the IPCC website at http://www.ipcc.ch or review progress of the 5 th report at http://www.ipcc.ch/index.htm#.T0Z7t3kQOHg
- Soil carbon sequestration is regarded as the number one potential source of agricultural greenhouse gas mitigation by the Intergovernmental Panel on Climate Change (United Nations, fourth assessment report, http://www.ippc.ch). Some of the ways that farmers can increase carbon capture in soils are: Conservation tillage or no-till Switching from annual to perennial crops Cover crops Applying organic materials (manure or compost)
- Biofuels include ethanol fermented from corn or other starchy grains. You will also commonly find biodiesel made from soybeans and other oil crops. These are considered the “first generation” of biofuels as they are made from readily processed grains. When compared to fossil fuels, corn ethanol is estimated to result in 20% less greenhouse gas emissions (US Department of Energy http://energy.gov/downloads/ethanol-myths-and-facts), however, some University of Nebraska research indicates that this number may be a 50% (or better) reduction (http://digitalcommons.unl.edu/cgi/viewcontent.cgi?article=1617&context=animalscinbcr). This number is expected to improve as the manufacturing process becomes more efficient and as grain farmers continue to make improvements in production efficiency. Pure biodiesel is estimated to reduce greenhouse gas emssions 75% compared to petroleum diesel (US Department of Energy http://www.afdc.energy.gov/afdc/pdfs/47504.pdf). There is also rising interest in biofuels made from fibrous materials like switchgrass, forest products, or crop residues. Biofuels fermented from these sources of biomass are referred to as “second generation” or advanced biofuels. These are estimated to reduce greenhouse gas emissions 86% when compared to fossil fuels (US Department of Energy http://energy.gov/downloads/ethanol-myths-and-facts). Another “advanced biofuel” is oil made from algae. This process depends on algae using manure or other wastewater as a food source. The oil produced by the algae can be used to replace fossil fuels in many different applications. At the time of publication for this module (2012) second generation biofuels are being actively researched but are not at commercial production scale. While biofuels have a great deal of mitigation potential, it also has the potential to be “too much of a good thing” if it contributes to indirect emission increases through land use changes or if they displace other sources of renewable fuel instead of displacing fossil fuel combustion.
- On an earlier slide you saw that nitrous oxide emissions from ag soil management was one of the largest agricultural sources of greenhouse gases. In a perfect world, plants would use every ounce of nitrogen fertilizer that was applied to a field or pasture. In reality, it is impossible to exactly predict weather, soil, yields and other factors. Nutrient and manure management plans are an important step in improving nitrogen use efficiency. Nutrient management plans or NMPs are where you calculate the nutrient needs (mostly nitrogen and phosphorus) of the planned crop (based on the estimated yield). That gives you the total amount of nutrients needed. From that you subtract nutrients already in the soil (which is calculated through a soil test), legume credits, and manure or compost applications. The amount left tells a farmer how much inorganic fertilizer should be applied. Improving nitrogen use efficiency reduced the amount of nitrogen fertilizer needed per bushel yield, which in turn, reduces the indirect greenhouse gas emissions generated during the production of fertilizer. Through precision agriculture and variable rate technologies, is it possible to deliver nutrient levels that are better matched to the micro-conditions of very small sections of a field. Other technologies, like nitrification inhibitors also show potential to reduce nitrous oxide emissions from fields. In most situations, farmers apply nitrogen fertilizer at the beginning of the crop season. The soil bacteria work to convert that nitrogen (usually ammonia or ammonium) into nitrate (the form of nitrogen that plants take in as food). This means there is a great deal of nitrate sitting in the soil. As the growing season progresses, plants will take up that nitrate as part of their growth. However, nitrate is very mobile, meaning it can leach down through the soil profile or be carried in runoff water and pose water quality risks. Nitrate also can undergo denitrification—yielding nitrous oxide or N2 gas. Nitrification inhibitors slows down the soil bacteria’s conversion of ammonia/ammonium to nitrate. This slow-down allows inorganic fertilizers to somewhat mimic timed-release fertilizers or breakdown of organic sources of nitrogen. This slower release of nitrate means that plants will have a constant supply of food and less nitrate is available for conversion to nitrous oxide.
- Covered manure storage captures the gases from decomposing manure (which is mostly methane). The methane is captured and can be burnt (reducing it to less potent carbon dioxide) or it can be collected in an anaerobic digester and used to generate electricity. Generating electricity results in additional greenhouse gas reductions if it replaces electricity produced from fossil fuels. Other carbon-based waste products can be added to anaerobic digesters, like vegetable oils and food wastes. An introduction to anaerobic digestion and biogas production is found at: http://www.extension.org/pages/26608/introduction-to-biogas-and-anaerobic-digestion After manure or the wastes have been digested, the resulting liquid still retains all of the original nutrients and can be applied to crops or pastures as a fertilizer.
- Ruminant animals (cattle, sheep, goats) emit methane as a by-product of feed digestion. As a general rule, highly digestible feeds such as grains result in fewer direct methane emissions than less-digestible feeds which means that animals consuming grain-based diets create less direct methane emissions than animals consuming forage or grass based diets. You will also notice that N2O or nitrous oxide is listed behind animal diet, this is a lower concern than methane when it comes to animal diet, but the high potency of nitrous oxide means that is should not be ignored. Research has shown that carefully matching animal protein needs with feed ingredients and not over-feeding protein can reduce nitrogen levels in manure which will, in turn, reduce nitrous oxide emissions from manure storage or land application of manure.
- Reducing fuel and electricity use on farms not only reduces greenhouse gas emissions, but should have a positive impact on the bottom line for a farm or ranch. Some examples: Switching to no-till or reduced tillage Insulating buildings to reduce heating/cooling Energy efficient light fixtures Utilizing natural light in buildings Optimizing irrigation water use
- When reducing greenhouse gas emissions, it is important to note that there are some action that might reduce one greenhouse gas but increase a different one. They may also reduce direct emissions but increase indirect emissions. That does not mean we should not try to reduce emissions, it just means that those making decisions on farms or those crafting policy and programs need to consider the whole system and make choices that produce the best net reduction that can be achieved within our financial and management abilities. The next two slides present examples where we may need to make trade offs in finding the best ways to reduce greenhouse gas emissions.
- There is no right or wrong answers here….the point is to recognize that no solution is perfect and that, at some point, there are real trade-offs that have to be compared. This applies to a farmer deciding what to feed their livestock as well as to policy makers trying to craft programs that achieve the best possible balance between food production and greenhouse gas emissions. Some discussion points (if needed): --Although measuring direct emissions (methane directly produced by the animal) favors grain-based diets, indirect emissions related to grain production such as fossil fuel use and soil carbon favor forage diets. --A conclusion that seems universal is that regardless of production system, farmers and ranchers should strive for high efficiency, producing the most usable product in relation to inputs consumed. --What types of scientific research can help address these issues (Hint: scientists are working to identify and breed highly digestible forage varieties. They are also studying rumen microbes to see if there are microbes that can digest forage while producing less methane, other?) --If you were a policy maker, what types of information would you need before creating programs? (range and pasture acres and trends over time, amount of methane emitted from animals consuming different diets, greenhouse gas emissions related to different land uses, water pollution, soil erosion, wildlife habitat, grain to feed humans vs livestock, use of non-human edible feeds, animal health & welfare, air quality, nutritional profiles of final animal product (meat, milk), economics, consumer demand, other?)
- There is no right or wrong answers here….the point is to recognize that no solution is perfect and that, at some point, there are real trade-offs that have to be compared. This applies to a farmer deciding what to plant on their own land as well as to policy makers trying to craft programs that achieve the best possible balance between food production and greenhouse gas emissions. Some discussion points (if needed): --What will happen to the world food supply if significant amounts of corn, wheat, rice, or other annual grains are not produced? Can intercropping of perennials meet world food demand? --Would feeding more forages to ruminants reduce need for annual grain production? (Back to discussion on previous slide). --Will second generation biofuels allow land that is now growing corn/soy for biofuels to sequester carbon as perennials? --What types of land would be brought into production to address food shortages? Forests? Marginal lands? What could massive deforestation or low productivity do to greenhouse gas emissions? --What types of scientific research is needed to help bridge the gap in this issue? (Hint: there are plant breeders already working on creating perennial varieties of common grains and on improving yields of promising perennial plants) --If you were a farmer or rancher, what types of incentives would make you consider converting some land into perennials? (direct payments, cost share, awards or recognition, new business opportunities such as agritourism, other?) --If you were a policy maker, what types of information would you need before creating programs? (crop land acres, average production, projected production, world demand for grains, trends in land use—converting crop land to pasture and vice versa, estimates of greenhouse gas emissions/capture from different types of land use, other?)
- There are a few key items when it comes to policy or regulation and mitigation of greenhouse gases. The first two points on this slide are existing rules or programs. The last three relate more to actions that may be taken in the future. The first key item is the US Environmental Protection Agency (EPA) finding that greenhouse gases “endanger human health and well-being” largely due to their impacts on climate. This finding was finalized by EPA in December 2009 and published in the federal register in January, 2010. This the first step that allows EPA to regulate GHGs as pollutants under the Clean Air Act. The immediate impact of the finding is that EPA could continue with a rulemaking process that proposed GHG standards for light-duty vehicles. Over the long term, it is not clear what the impacts on agriculture could be, although many ag organizations are concerned about potential permitting, emissions reductions, and other possibilities. The Clean Air Act is a complex piece of legislation, but it also has a clearly defined scope and limitations. Over the next few years, many industries and organizations, including agriculture, will be watching how and where EPA applies their authority in regulating GHGs. (Source: http://epa.gov/climatechange/endangerment.html) The next important piece of policy that is related to agriculture is the Mandatory Greenhouse Gas Reporting rule. (http://www.epa.gov/climatechange/emissions/ghgrulemaking.html). Under this rule, very large sources of greenhouse gas emissions (more than or equal to 25,000 metric tons per year) are required to make an annual report to EPA. Some of the very largest livestock and poultry farms were calculated to be in this category. However, Congress has prohibited EPA from spending any money to enforce subpart JJ (manure management) of the rule effectively blocking application of this requirement to livestock or poultry at this time (early 2012). For this prohibition to continue, it needs to be renewed every year during the budget process. The two most common scenarios discussed when looking at greenhouse gas regulations are “cap and trade” and carbon tax. Cap and trade is the more complex of the two--where the government sets a maximum amount of greenhouse gas emissions (“cap”) and decides which industries must comply with the limits. Those industries can buy credits from other sources (like agriculture) who sequester carbon (“trade”). Proponents believe it can be successful since this system was successfully used in the 1990’s to eliminate sulfur pollution (which created the infamous acid rain). Opponents believe this system would cripple businesses and affect even non-regulated industries by increasing the price of energy and fuel. The U.S. House of Representatives passed a bill in 2009 that would have created a cap and trade system by an extremely narrow margin and amidst bitter partisan debate. The Senate was not able to agree on a bill and the process was abandoned in 2010. Proponents of a carbon tax see it as a much simpler system than cap and trade, but is generally not considered to be as politically viable as cap and trade. Just as the name implies, a price (tax) is set for each ton of carbon emitted by fuels. This provides an economic disincentive to use fuels that are more carbon intensive and makes less carbon-intensive fuels more economically attractive. This system does not actually set any limits on emissions, but strives to make it more expensive for large emitters to do business. Opponents of the carbon tax approach are generally the same groups as opposing cap and trade—and give the same reasons for their opposition. In the absence of federal action on the greenhouse gas or climate change regulation, some states have considered their own rules and policies. On January 1, 2012, California’s cap and trade system kicked off. (http://www.arb.ca.gov/cc/capandtrade/capandtrade.htm). Farms and ranches are not regulated under this legislation. The successes and/or struggles of this program are likely to be closely watched by supporters and opponents alike.
- The opportunities for agriculture in reducing greenhouse gases are numerous. Since agriculture is a system built on biological processes, it will be looked to as more emphasis is placed on mitigation or sequestering carbon from the atmosphere. Until some type of comprehensive legislation or policy is put into place at the state or federal level, those opportunities are likely to take the form of voluntary participation. The opportunities generally fall into the following four categories: 1) Reducing input costs are an obvious benefit for farmers or ranchers that are able to decrease the use of things like fertilizer, electricity, or fuel especially when these changes can be made without compromising productivity. 2) Carbon payments are available through organizations that sells carbon credits to companies that have decided to offset some or all of their carbon footprint. These types of programs require verification that the farm or ranch is actually doing what they say and also generally require some record keeping. Farmers work through an aggregator who basically bundles the efforts of individual farmers until they have enough carbon credits to offer on the market. The market price for these credits fluctuates over time based on supply and demand. Renewable energy credits 3) Incentivizing best management practices is basically paying farmers or providing assistance for adopting or continuing practices that are known to be effective ways to sequester carbon. These programs might emphasize practices like no-till or nutrient management plans. In some areas farmers can look at tax credits or loan guarantees for building an anaerobic digester. Existing programs like the Conservation Reserve Program (CRP) are likely to continue in the future based on carbon sequestration potential. CRP pays farmers to take land out of annual crop production and instead plant perennial grasses and leave them for a set period of time (usually 10 years) and was developed as a way to decrease soil erosion. Another program of note is NRCS Conservation Security Program (CSP). It will pay for undertaking additional conservation activities; and improving, maintaining, and managing existing conservation activities. This includes perennial waterways, pasture improvement practices, cover cropping, inter-cropping, nitrogen management, and irrigation efficiency. 4) Another way that greenhouse gas mitigation can provide opportunities for farmers is through marketing their products. More and more farm operations are looking at direct marketing. With a high level of public interest in sustainability, farms and ranches that are able to connect with their customers concerns about environmental impact will have a marketing advantage. Carbon footprint and sustainable management practices are high on the lists of many customers/potential customers. In the future, it is conceivable that some marketing opportunities will require its participants to adopt certain practices or maintain a low carbon footprint.
- To summarize some of the important points from today, you need to remember that agriculture is a significant source of methane and nitrous oxide—two very potent greenhouse gases. The main activities that emit these are soil management, enteric fermentation, and manure management. Another important point is that many things that are currently recommended to farmers and ranchers as best management practices are also complimentary to the effort to reduce greenhouse gases. Things like increased soil organic matter (organic matter refers to carbon in soils), nutrient management plans, covered manure storage, and others are tools that protect water or air quality and also can reduce greenhouse gases emitted to the atmosphere. Producing the most product with less inputs will also continue to be important, and for reasons that go beyond climate change. Agriculture is a diverse industry and that is one of its strengths. Regardless if farms and ranches are large or small, organic or “conventional”, commodity producers or value-added producers, each operation should find ways to maximize the production achieved from water, fuel, fertilizer, management skills, and other inputs.
- As agriculture prepares for the future, it is prudent to prepare for climate change scenarios as part of the farm/ranch/agribusiness risk management strategy. Farmers and ranchers may also find different financial opportunities stemming from the potential for agriculture to sequester carbon from the atmosphere or reduce their emissions. The possibility of regulations, while currently unlikely at the federal level, does remain a distinct possibility, especially if other states follow California’s lead. Farmers and ranchers need to stay informed about this topic and remain involved in the process in order to advocate for policies or programs that are based on sound science and achievable goals.
- Ag teachers—you can omit this slide. Extension educators/agents—Replace Jill ‘s contact information with your own.