Ozone Impacts on Crop Yields: Regional and Global Assessments and Mitigation Potential Denise L. Mauzerall and Rita Van Dingenen

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1 Ozone Impacts on Crop Yields: Regional and Global Assessments and Mitigation Potential Denise L. Mauzerall and Rita Van Dingenen with Shiri Avnery, Larry Horowitz, Arlene Fiore, Junfeng Liu, and Frank Dentener HTAP meeting Beijing, China May 21, 2014

2 O 3 Pollution Reduces Crop Yields Large-scale, open top chamber (OTC) field studies used to derive concentration:response functions to predict crop loss at a given level of O 3 exposure (defined by mean and cumulative O3 concentration metrics during the growing season). U.S. National Crop Loss Assessment Network (NCLAN) study in 1980s European Open Top Chamber (EOTC) program in 1990s Smaller-scale studies in Asia and other developing countries

3 Key Questions 1. What are present and potential future crop losses due to O 3 exposure? 2. How much can methane reductions reduce surface O 3 concentrations and hence protect crops while providing cobenefits for climate? 3. How much can agricultural yields be improved by choosing O 3 resistant crop cultivars? 4. How important is inter-continental transport in determining O 3 concentrations and crop losses?

4 Outline Summary of methods and findings from: Princeton study: Avnery et al., 2011a,b and European Commission study: Van Dingenen et al Hemispheric Transboundary Air Pollution (HTAP) report, 2010.

5 Method: Integrated Assessment Steps 1) Simulate surface O 3 concentrations globally Method Use global chemical transport model (MOZART-2 or TM5) 2) Calculate plant exposures to O 3 during growing season Use various exposure metrics (mean and cumulative) for each scenario 3) Calculate Yield Loss Estimate using concentration:response functions obtained from the US NCLAN field study and Mills et al. (2007). Convert to crop production loss 4) Economic Valuation Estimate value of lost production based on producer prices in 2000

6 Year 2000 O 3 Exposure Mean 12 hours Cumulative AOT40 Soybean Maize Wheat

7 Yield Loss in 2000 Mean 12 hours Cumulative AOT40 Soybean Global year 2000 yield losses 4-15% for wheat, 9-14% soybean, 2-6% for maize Crop production losses ~ Mt worth $11-18 billion USD 2000 annually Maize Wheat Avnery et al., Atmospheric Environment 45 (2011), doi: /j.atmosenv

8 Economic Losses from Reduced Grain Yields in 2000 U.S. China India Iran Canada Pakistan Turkey Italy Total EL Total Economic Loss (EL) Syria Brazil Average M12 AOT EL (Million USD)

9 Optimistic and Pessimistic O 3 Precursor Emission Scenarios for 2030 Emissions from IPCC SRES A2 and B1 scenarios A2- Pessimistic B1 - Optimistic Difference between A2 and B1 simulations indicates potential decreases in O 3 and associated crop yield benefits. Tg NO2 / yr Tg / yr NMVOC Emissions 0 NO x Emissions Tg CO / yr Tg CH4 / yr CO Emissions CH 4 Emissions A2 B1

10 Pessimistic Yield Loss in 2030 (A2) Soybean 2030 A2 global yield losses range from 5-26% (+2-10%) for wheat, 15-19% (+1-11%) for soybean, 4-9% for maize (+2-3%) Crop production losses Mt worth $17-35 USD 2000 (+$6-17 billion) annually Maize Wheat Avnery et al., Atmospheric Environment 45 (2011), doi: /j.atmosenv

11 Increase in Economic Losses under Pessimistic Scenario (2030A2 2000) Total India China U.S. Iran Brazil Turkey Pakistan Syria Egypt Russia Change in EL (Million USD) Average M12 AOT Change in Economic Loss (Million $US) Change in Economic Losses Under Optimistic Scenario (2030B1 2000) China India U.S. Total Brazil Improving air quality through reductions in ozone precursors increases crop production. Iran Italy Japan Pakistan Canada Argentina Average M12 AOT Change in EL (Million USD) Change in Economic Loss (Million $US)

12 Benefits of Reducing Conventional Ozone Precursors Improving air quality through reductions in conventional ozone precursors increases crop yields. India, U.S., and China experience greatest gains >$1.5 billion each India United States China Iran Turkey Syria Pakistan Egypt Russia France Change in 2030 EL (2030A2 2030B1) Change in EL (Million USD 2000 ) M12 AOT40 Average

13 How much can Methane (CH 4 ) Mitigation or use of O 3 Resistant Crop cultivars Improve Crop Production? Method: Same approach as part 1, but use the 2030 Current Legislation (CLE) emission scenario Methane Mitigation Benefits 2030 CLE emissions scenario compared with 2030 CLE reduced methane emission scenario (2030 CH 4 -red scenario ). Crop Cultivar Selection Benefits Use minimum-sensitivity O 3 -response function for each crop and compare to median-sensitivity results 2030 CLE scenario benefits of adaptation only policy 2030 CH 4 -red scenario benefits of both mitigation & adaptation policies.

14 Methane Mitigation Scenarios CLE ( Current legislation ): Global anthropogenic emissions of CH 4, NO x, CO, and NMVOC change by +29%, +19%, -10%, and +3%, respectively from CLE CH 4 -red CH 4 -red: Reductions begin in 2006, grow to 125 Mt yr -1 by 2030 (29% decrease from CLE 2030)

15 Crop Production Gains in 2030 due to CH 4 Control AOT40 Crop production increases ~ Mt, 85% due to wheat yield improvements Prevents 10-45% of the O 3 -induced crop production losses under 2030 CLE Globally, increases production by ~2-8% of 2000 levels, most significant gains for India, China, U.S., Middle East & N. Africa W126

16 Economic Gains in 2030 due to CH 4 Control AOT40 Crop production gains due to CH 4 mitigation worth $ billion Significant regional variability, economic benefits concentrated in regions of major agricultural production (Indian subcontinent, China, U.S.) W126

17 Benefits of Ozone Resistant Cultivar Selection in 2030 Increase crop production by +140 Mt in 2030, equivalent to a 12% improvement in year 2000 production worth ~$22 billion Greater economic gains in regions where soybean and maize are the primary sources of CPL (NA and EA) compared to CH4 mitigation policy Largest economic benefit in Indian subcontinent (~74%), followed by the U.S. ($2.5 billion) and China ($1.2 billion)

18 Benefits of Combined Methane Mitigation and Ozone Resistant Crop Cultivar Selection Lead to crop production improvements of +170 Mt in 2030, equivalent +14% from year 2000 production, worth $26 billion. Benefits to agriculture less than fully additive.

19 Methods used by Van Dingenen et al., 2009 and HTAP: 4 staple crops (wheat, maize, rice, soybean) CTM: TM5, 1 x1, emissions: 2000, CLE 2030 Hourly surface ozone AOT40, M7, M12 stored as monthly maps Start crop growing season (calculated as subsequent 3 months) and suitability index: GAeZ (Fischer et al., IIASA)

20 Method: 3-month seasonal mean daytime O3 Wheat suitability index Wheat production loss

21 Potential for reduction of crop losses (crop increases) HTAP 2010: pollutant emissions reduced 20% globally Change in RYL, 20% emission reduction all pollutants globally INDIA CHINA NAM AFR WHEAT CORN SOY RICE EU25 WORLD -8% -7% -6% -5% -4% -3% -2% -1% 0% WORLD EU25 AFR NAM CHINA INDIA WHEAT -2.3% -1.4% -1.5% -1.9% -3.2% -3.5% SOY -2.0% -2.4% 0.0% -2.4% -2.9% -2.3% CORN -0.9% -0.9% -0.2% -1.0% -1.1% -0.7% RICE -0.7% -0.7% -0.3% -1.8% -1.0% -1.0%

22 HTAP 2010: Yield reduction due to domestic vs. imported ozone ~35% of O3-related wheat losses in Europe comes from long range transport -100% -80% RECEPTOR REGION EUROPE-25 EU NA EA SA -100% -80% RECEPTOR REGION USA NA EU EA SA -60% -60% -40% -40% -20% -20% 0% Wheat Rice Maize Soybean 0% Wheat Rice Maize Soybean RECEPTOR REGION CHINA RECEPTOR REGION INDIA ~80% of O3-related crop losses in China are due to domestic emissions -100% -80% -60% -40% EA NA EU SA -100% -80% -60% -40% SA EA NA EU -20% -20% 0% Wheat Rice Maize Soybean 0% Wheat Rice Maize Soybean

23 Conclusions O 3 exposure results in substantial yield reductions in many parts of the world with India, China and US most affected. Depending on future emissions of O 3 precursors, global impacts could increase substantially. Opportunities to improve yields sustainably exist via reduction in emissions of short-lived O 3 precursors and CH 4. Use of O 3 resistant crop cultivars can reduce damages. Crop yields are primarily impacted by domestic emissions, though for some regions (especially Europe) inter-continental transport is important.

24 Future Research Needs - Extend impact assessment to additional crops, forests, etc. - Obtain field data on current crop cultivars to update O 3 damage metrics - Explore using flux rather than exposure calculations in evaluation (much more data needed). - Understand the relative and synergistic impacts of climate change and O 3 on crop production and food security. - Evaluate impact of NO x emissions from excess fertilizer use on O 3 production and yield loss. - Role for Earth System modeling (Land model Atmospheric Chemistry Climate)

25 Results available in: Avnery, S, DL Mauzerall, J Liu, LW Horowitz. Global Crop Yield Reductions due to Surface Ozone Exposure: 1. Year 2000 Crop Production Losses and Economic Damage, Atmospheric Environment, 45, Avnery, S, DL Mauzerall, J Liu, LW Horowitz. Global Crop Yield Reductions due to Surface Ozone Exposure: 2. Year 2030 Potential Crop Production Losses and Economic Damage under Two Scenarios of O3 Pollution, Atmospheric Environment, 45, Avnery, S, DL Mauzerall, AM Fiore. Increasing global agricultural production by reducing ozone damages via methane emission controls and ozone resistant cultivar selection, Global Change Biology, 19, Van Dingenen, R, F Dentener, F Raes, M Krol, L Emberson, J Cofala, The global impact of ozone on agricultural crop yields under current and future air quality legislation, Atmospheric Environment, 43, Hemispheric Transport of Air Pollution: 2010 report, Part A: Ozone and Particulate Matter, Chapter 5, 2010

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27 Overview of Major Sources of Uncertainty Simulated hourly O 3 concentrations by a global CTM to predict O 3 exposure Metrics and CR relationships that were derived from OTC studies in the U.S. and EU in the 1980s/90s applied globally due to the lack of similar large-scale studies elsewhere Recent studies suggest current cultivars are at least as sensitive to those from which CR functions were derived (Morgan et al., 2006; Biswas et al., 2008; Emberson et al., 2009; Feng and Kobayashi, 2010; Zhu et al., 2011; EPA, 2011) For benefits of CH 4 mitigation, O 3 reductions will continue beyond 2030; benefits not included Changes in future production or commodity prices not accounted for No provision for farmer adaptation to O 3, but benefits of altering crop calendars or watering regimes appear limited globally (Teixeira et al., 2011) Potential effect of climate change on stomatal conductance not accounted for, nor direct impact of climate change on crops