Air pollution impacts Agriculture
Maheswar Rupakheti Group Leader Institute for Advanced Sustainability Studies (IASS) Potsdam, Germany
Institute for Advanced Sustainability Studies e.V.
Media regional Training, 18 Nov 2015, ICIMOD, Kathmandu
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Introduction Agriculture in South Asia in the global context Source: USDA, Nov 2015
Examples (year 2013/14):
• South Asia contributes significantly to world crop production (rice, wheat, soybean, cotton, sorghum, oil seeds etc.) •
South Asia, particularly vast Indo-Gangetic Plains (highly populated and heavily cultivated region), is one of the heavily polluted regions of the world 2
Introduction Sunlight
Air (Carbon dioxide, oxygen, others*)
Climatic Conditions (Temperature, humidity, rain)
Key air pollutants that affect crops (Soil, water, nutrients) • Ground level ozone (O3) • Particulate matter (PM) • Acidic compounds • Ammonia • Nitrogen and Phosphorous (Nutrients)
Medium
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How does air pollution affect crops/agriculture? Direct effects
Indirect effects
• Reduction of incoming solar radiation (photosynthetically active radiation, PAR)
• Change in climatic conditions (Temperature, humidity, clouds, extreme events)
• Deposition of pollutants on plants (aerosols/gases)
• Change in hydrological cycle and water availability
• Acidification/acid rain • Damage due to ozone
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How does air pollution affects crops? • Reduction of incoming solar radiation
• Change in climatic conditions (temperature, humidity, clouds, extreme events)
• Change in hydrological cycle and water availability • Deposition of pollutants on plants
• Damage due to ozone 5
Direct effects
Monsoon rain
Glacier melting
Indirect effects
Ozone is the main pollutant that affects crops Foliar injury Accelerate senescence (aging) Decrease plant growth Alter plant metabolism Reduce ability to sequester carbon Reduce crop yield
KHG-11
Bel-W3 Bel-W3
Courtesy: L. Ainsworth
• • • • • •
Effects of different levels of ozone on soybean 6
Ozone injury on tobacco plant (Lahore)
South Asia is a global ozone hotspot
The Royal Society 2008
Surface ozone in Year 2000 (ppb)
South Asia: Most ozone polluted region in the world by 2030 (Dentener et al 2006) 7
Source: USDA, www.fas.usda.gov,
Courtesy: K. Mahata
Ozone seasonal variation and crops cycle in Asia
AOT40: accumulated exposure to ozone above 40 ppb = hourly conc.x hours (ppm.h) 8
Ozone impact on crops: Global/Regional
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CCAC, 2014
Agriculture benefits of ozone mitigation
Largest benefits China: 12.7 mil. MT India: 9.8 MMT USA: 6.3 MMT Pakistan:2.1 MMT Brazil:1.6 MMT
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CCAC, 2014
Aufhammer et al, 2007
Impacts of ABCs & GHGs reductions in rice in India
Predicted increases in wet-season rice harvest in Indian in response to reductions in ABCs (PM, O3) and GHGs 11
Burney and Ramanathan, 2014
Climate and air pollution impact on Indian agriculture
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RYC: [Model(2006-2010avg)-Baseline(2006-2010avg)/ Baseline(2006-2010avg)]
Summary •
Ground level ozone is the main air pollutant responsible for crop losses [Globally wheat: 7-12%, Soybean: 6-16%, Rice: 3-4%, Corn: 3-5%] Harmens, 2011,
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Particulate air pollutant also affects crops in several ways (deposition on leaves, cut down solar radiation, change in clouds and precipitation pattern).
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Combined effects/impacts of climate change and air pollution, in particular extreme climate events are yet to be fully understood (further research needed)
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Agriculture sector is double-hit by air pollution and climate change. Any efforts to mitigate impacts of air pollution and/or climate change should go simultaneously.
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There is urgent need to sensitize through media that reductions in key air pollutants could avoid a substantial amount of crop loses in South Asia.
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Key References: 1. 2. 3. 4.
Ramanathan et al,. Atmospheric Brown Clouds: Regional Assessment with Focus on Asia,, UNEP, 2008 UNEP/WMO. integrated assessment of black carbon and tropospheric ozone, UNEP, 2011 CCAC. Time to Act, CCAC/UNEP, 2014 Burney, J. and Ramanathan, V. Recent climate and air pollution impacts on Indian agriculture, PNAS, 2014
Institute for Advanced Sustainability Studies e.V.
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Some remarkable changes in S. Asia N-S Shift in Asian rainfall
Weakening Indian monsoon Sahelian drought
Observed rainfall during 1950-2002
- Weakened Asian Monsoon (~7%) - 20% decrease in rainfall in Indo-Gangatic plain since 1980s. - Accelerated melting of Hindu Kush-Himalayan-Tibetan glaciers due to BC deposition on snow/ice and atmospheric solar heating. 15
Soybean
9.0 6.0 3.0 0.0
T0
Shoot T120
Root
Total
Courtesy: U. Chopra
Height (cm)
12.0
T0 – filtered air with zero ozone T120: air with 120 ppb ozone Institute for Advanced Sustainability Studies e.V.
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Mung Bean Plant without ozone protection
EDU Treated
Courtesy: M. Agrawal
Mung Bean Plant protected for ozone
Non - EDU Treated
EDU: Ethylene diurea Institute for Advanced Sustainability Studies e.V.
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Courtesy: M. Agrawal
EDU Treated
Institute for Advanced Sustainability Studies e.V.
Non - EDU Treated
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Effect of 400 ppm EDU treatment on yield parameters of mungbean plants
Parameter
Non – EDU EDU
Seed wt. (g plant-1)
3.30
6.26
Pod wt. ( g plant-1)
5.38
6.90
No. of seeds (plant-1)
85
148
No. of pods (plant-1)
16
31
Yield (g m-2)
223.12
432.65
(Singh et al., 2009, IJEWM, in press)
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Shindell et al, Science, 2012
Agriculture benefits of O3 & BC mitigation
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