Animal Production and Climate Change

Transcription

1 Animal Production and Climate Change Prepared for ANS401 Jan. 21 th, 2011 Zifei Liu Research Associate Departments of Animal Science and Biosystems & Agriculture Engineering

2 Is meat the new diapers? The diaper controversy The meat controversy Disposable diapers --> cloth diapers Trade convenience for sustainability? Stop eating meat to stop global warming? It turned out the story wasn t as simple as it first seemed. 2

3 Animal Ag is Under Attack The UN Food and Agriculture Organization s (FAO) 2006 report Livestock s Long Shadow Animal production contributes 18% to the total global warming emission. Since then, the meat-bashing momentum has snowballed One study even claimed that animal production was responsible for 51% of all global warming emissions (Goodland and Anhang, 2009)! 3

4 But the story is not that simple The global warming impact of different sources of meat and different ways in meat processing varies widely. Low-impact meats can actually be better for the climate than highly-processed vegetarian alternatives. (Angelique, 2010) 4

5 Doubt on the FAO report In Clearing the Air: Livestock s Contribution to Climate Change (2009), UC Davis Professor Frank Mitloehner claimed that the FAO report is giving an inaccurate impression of the impact animal production may have on global warming and putting us on a wrong path toward solutions. 5

6 Different numbers Animal production contributes 18% to the total GHG emission worldwide, higher than transport system (13.5%). (FAO, 2006) Animal production contributes less than 3% to the total GHG emission in US, compared to 26% from transportation. (EPA, 2009) The data in the FAO report is based on inappropriate or inaccurate scaling of predictions and does not apply to U.S. production systems (Pitesky et al., 2009). 6

7 Iclicker time! Have you heard of the FAO report, and how do you feel about its estimation on global warming contribution of animal production (18%)? A: I have heard of it and trust its conclusion. B: I have heard of it but I suspect there is overestimation. C: I think the actual contribution can be bigger than 18%. D: I have no idea. 7

8 Question 1: Indirect contributions through deforestation? The land use change related to animal production (mainly deforestation) contributes over 35% to the FAO estimate of livestock production carbon footprint. However, deforestation did not occur in most developed nations. In fact, in the last 25 years, forestland in the US has increased by 25% while total agricultural production has increased. (Pitesky et al., 2009) 8

9 Question 2: Comparison not apples to apples? vs. The FAO report does not use equivalent comparison methods to evaluate the contributions of the animal agriculture and transportation sectors. Life cycle assessment was used only in animal agriculture but not in transportation sectors. (Pitesky et al., 2009) 9

10 Question 3: Alternative emissions not estimated If animal production was simply eliminated, there is no estimate of what substitute GHGs would be produced in their place The idea that 18% of global GHGs would also be eliminated is unrealistic. (Pitesky et al., 2009) 10

11 A clearer picture on the actual contribution of animal production on GHG emissions is needed. 11

12 The concept of carbon footprint A carbon footprint is a measure of the impact of our activities on the environment, and in particular climate change. It is the total GHG emissions caused directly and indirectly by the activities. 12

13 The CO 2 -eq units Each GHGs CO2, CH4, N2O, etc. has a different global warming potential. Emissions of different gases have to be converted to CO 2 -eq units so they can be added together to get a picture of total emissions CO2 23 CH4 N2O 13

14 CO 2 generated by animal - biogenic in nature or carbon neutral Source: Scottish Centre for Carbon Storage (2009) 14

15 (Source: World Resource Institute) 15

16 Iclicker time! Did you know CO 2 generated by animal is often not considered in estimates of impact on climate change? A: I did know. B: I did not know until now. C: I think CO2 from animal should be considered. D: I have no idea. 16

17 Main elements in an typical person's carbon footprint in the developed world Primary footprint: direct emissions (green slices) Secondary footprint : indirect emissions (yellow slices) (Source: Carbon Footprint) 17

18 GHG emission inventories The Intergovernmental Panel on Climate Change (IPCC) has developed guidelines for estimating and reporting emissions of GHG from AFOs (IPCC, 2006) Official GHG inventories are reported annually by each country to the United Nation Framework Convention on Climate Change (UNFCCC). The Kyoto protocol restricts the total GHG emissions of each signature country and the protocol provides an opportunity for emission trading within signature countries.

19 Estimating CH 4 emission using the IPCC approaches Manure CH 4 emission Enteric fermentation CH 4 emission Total CH 4 emission =VS B o 0.67 MCF Excreted volatile solid maximum CH4 producing capacity CH4 conversion factor Swine: 4.2 g head -1 day -1 Steers: 145 g head -1 day -1 Dairy cows: 351 g head -1 day -1 19

20 Estimating N 2 O emission using the IPCC approaches N excretion rate N 2 O emission factor Direct N 2 O emission kg N (1000kg BW) -1 day kg N 2 O-N/kg N 20

21 IPCC methodology default N 2 O emission factors AWMS categories Emission factor Uncertainty Liquid/slurry Factor of 2 Pit storage Factor of 2 Aerobic treatment Factor of 2 Dry lots 0.02 Factor of 2 21

22 Doubts on the IPCC approaches Whether the IPCC approaches adequately capture the variation which exists in animal operations? Researches suggest that the IPCC approaches overestimated GHG emissions (Marinier et al.,2004; Park et al., 2006; DeSutter and ham, 2006) The CH4 conversion factors used in the IPCC approaches are flawed (Lory et al., 2010) There is a clear need for more studies to assess the validity of the IPCC approaches, to provide the basis for revision of EFs and to make EFs more locally applicable. 22

23 Meta-analysis of GHG from swine operation Compare the measured values of GHG emissions from swine operations in literature to the estimated values using the IPCC approaches. Identify and evaluate the causes of the variation in the reported GHG emissions 23

24 How do we reduce our carbon footprint? Driving less, using energy efficient appliances, buying local foods as well as products with less packaging, etc. 24

25 Is organic farming the solution? Organic farming is not friendlier to the environment than conventional farming. In fact, it s worse for the environment because it requires the use of more land to grow the same amount of food (Paarlberg, 2010) 25

26 Scientific efforts focused on reducing animal and farm emissions Improve feed efficiency Improve nutrition Ration balancing Feeding management Improve cropping practices & technology Improve manure management Storage Processing Application (Capper et al., 2009) 26

27 GHG emissions from animal productions in the U.S. have declined per unit of production. The GHG emissions from U.S. animal agriculture have remained relatively constant while protein production has dramatically increased Improved feed efficiencies Better manure-management strategies Efficient use of cropland Since 1990, Meat production : 50% Milk production : 16% Egg production : 33% (American Meat Institute, 2009) 27

28 Carbon footprint of a gallon of milk has been reduced by 2/3 since Productivity is the Reason Increase/ decrease U.S. Milk Production 117 billion lb Milk 186 billion lb Milk + 59% U.S. Dairy Cows 25.6 million Cows 9.2 million Cows - 64% (Capper et al., 2009) (USDA NASS, 2008, 28

29 The Real Challenge: Global Demand Requires More Food Technology s Role in the 21 st Century: Food Economics and Consumer Food industry needs technology to meet increase in food demands Consumers need choice 29

30 The increased demand for food can only be fulfilled via improved productivity Improved Production Efficiency More from Less Reduced Carbon Footprint per unit of output Sustainability 30

31 Using per unit of output rather than per unit of the production process Appropriate Food Animal Production Units Dairy : per unit of milk (eg. lb, kg, g, or l) or dairy product (eg. cheese) Meat : per unit of meat (eg. lb or kg) and/or no. of specific type of cut Eggs : per number of eggs 31

32 Carbon Footprint of Dairy and Cars 20 lb CO2-eq per gallon of gasoline 17.6 lb CO2-eq per gallon of milk, from farm to table (Source: M. L. Walser, 2010) (Source: University of Arkansas Applied Sustainability Center) 32

33 Greenwashing undermines the value of responsible efforts 1. Carbon-free sugar 2. Organic rocks 3. Certified organic sea salt (NaCl) 4. Organic cigarettes 5. No-calorie energy drinks 6. Organic charcoal 7. Carbon-neutral insurance 8. Zero-carb alcoholic drinks 9. Carbon-free shipping 10. Carbon-free computing Source: 33

34 Key points It is essential to evaluate environmental impact per unit of output rather than simply by unit of production Productivity is an important contributing factor in reducing the animal industry s environmental impact. Practices and technologies that increase production efficiency also reduce the carbon footprint, conserve resources, and improve agricultural stewardship U.S. industry has been decreasing the environmental impact of animal production per unit of production for decades Producing more from less =>Sustainability 34