Climate Impacts on Agriculture For Climatology Class 11/6/2014 1

Outline Agriculture is essential How does climate affect agriculture (lab experiment)? How do further climate changes affect agriculture? (1) Global warming scenario (2) Geoengineering scenario (3) A regional nuclear war scenario How agriculture system feedback on climate system? 2

[Elert, 2014] On average, every day, each person on the planet consumes: It is a challenge to feed the world in 2050 (1)Food demand increasing (2)Food distributed unevenly (3)Waste (4)Climate changes I. Agriculture is essential 3

(1) Food Demand is Increasing (under assumption of consumption patterns do not change) I. Agriculture is essential 4

[Elert, 2014] I. Agriculture is essential 5

In developing countries, calories per person is increasing with time [Alexandratos and Bruinsma, 2012] I. Agriculture is essential 6

(2 ) Food distributed unevenly I. Agriculture is essential 7

Kevin Carter, March 1993, Sudan A starving toddler trying to reach a feeding center when a hooded vulture landed nearby 8

(3) Waste Let’s calculate our carbon food print: I. Agriculture is essential Food Waste 9

The figure shows the average area of land needed to produce 1 tonne. Improve rice strains and modern agriculture techniques have meant that farmers can produce higher yields on a smaller area of land. 10

Global Temperature Relative to (4) Global climate impacts food production (IPCC, 2007) I. Agriculture is essential 11

 Photosynthesis  Respiration  Transpiration Movement of minerals and sugars Cooling Turgor pressure Osmotic pressure Capillary action I. Agriculture is essential (4) Global climate impacts food production 12

24 Solar Terms: (Liu A et al. 139 BCE) Temperature Precipitation Solar radiation CO 2 O3O3 Vernal equinox Autumnal equinox Summer solstice Winter solstice Climate Factors II. How does climate affect agriculture 13

Climate Factors - Temperature (Porter and Gawith, 1999) (Schlenker and Roberts, 2006) Wheat Rice Maize (Nishiyama et al., 1976) II. How does climate affect agriculture 14

Climate Factors - Precipitation [Jalota et al., 2007] Wheat Rice MaizeCotton II. How does climate affect agriculture 15

PAR(μmol m -2 s -1 ) [Mercado et al., 2009] Climate Factors – Solar Radiation Simulated direct light Observed direct light Observed diffuse light Simulated diffuse light II. How does climate affect agriculture 16

[Dayton, 2014] II. How does climate affect agriculture Climate Factors – CO 2 CO 2 fertilization effect [Leadley and Drake 1993] 17

[Avenery et al., 2011a, b] Climate Factors –O , A2 Total crop production loss (CPL) II. How does climate affect agriculture 18

Predict future climate impact on agriculture Climate Forcing Soil Property Agriculture Data Crop Model Statistic Model Dynamic Model Climate Forcing Observation Climate Model Simulation Soil properties Physical properties Chemical properties Agriculture Data Crop distribution Planting date Cultivars Irrigation Fertilizer Pesticide III. How do future climate change affect agriculture? 19

What is Dynamic Crop model? Example: DSSAT Main Program Weather Management Soil Plant Soil-Plant- Atmosphere Planting Harvesting Irrigation Fertilizer Residue Tillage Daily Tmax Daily Tmin Daily Precip. Daily solar radiation Water N P Organic matter Dynamics Maize Wheat Rice Potato Other crops CO 2 III. How do future climate change affect agriculture? 20

[Lobell et al., 2008] III. How do future climate change affect agriculture? (1) Global Warming scenario – Case study – Statistic Crop Model Climate changes for 2030 in different regions (based on 20 General Circulation Models and three emission scenarios) 21

[Lobell et al., 2008] (1)Negative Impact: SAF-maize SAF-wheat (2) Large uncertainties SAS-groundnut SAF-sorghum (3) No changes WAS-wheat 22

[Rosenzweig, 2014] Median yield changes (%) for RCP8.5 (2070–2099 in comparison to 1980–2010 baseline) with CO2 effects over all five GCMs x seven GGCMs (6 GGCMs for rice) for rainfed maize (35 ensemble members), wheat (35 ensemble members), rice (30 ensemble members), and soy (35 ensemble members). (1) Global Warming scenario – Case study – Dynamics Crop Model III. How do future climate change affect agriculture? 23

Relative change (%) in RCP8.5 decadal mean production for each GGCM (based on current agricultural lands and irrigation distribution) from ensemble median for all GCM combinations with (solid) and without (dashed) CO 2 effects for maize, wheat, rice, and soy; bars show range of all GCM combinations with CO 2 effects. GEPIC, GAEZ-IMAGE, and LPJ-GUESS only contributed one GCM without CO 2 effects. III. How do future climate change affect agriculture? (1) Global Warming scenario – Case study – Dynamics Crop Model [Rosenzweig, 2014] 24

III. How do future climate change affect agriculture? (2) Geoengineering scenario “In light of the failure of society to take any concerted actions to deal with global warming ….. two prominent atmospheric scientists published papers recently suggesting that society consider geoengineering solutions to global warming…” [Robock et al., 2008] “There are been many types of suggested geoengineering, including … changing the CO 2 concentration in the atmosphere … damming the ocean … reducing the incoming solar radiation …“[Robock et al., 2008] 25

Tropopause Space-based reflectors Stratospheric aerosols Cloud brightening Surface albedo modification Solar Radiation Management Earth surface III. How do future climate change affect agriculture? 26

“Simulated geoengineering reduced precipitation over wide regions, condemning hundreds of millions of people to drought.” [Robock, 2008] [Robock et al., 2008] III. How do future climate change affect agriculture? (2) Geoengineering scenario 27

- standard experiments with the new GCMs being run as part of CMIP5 using identical global warming and geoengineering scenarios, to see whether precious results are robust. GeoMIP – The Geoengineering Modeling Intercomparison Project (Kravitz et al., 2011) G2: In combination with 1% CO 2 increase per year, gradually reduce the solar constant to balance the changing radiative forcing. 28

Global Temperature Changes – G2 Geoengineering [Jones et al., 2014] dotted lines are +1%/yr CO 2 solid lines are G2 29

Global Precipitation Changes – G2 Geoengineering [Jones et al., 2014] dotted lines are +1%/yr CO 2 solid lines are G2 30

( World population III. How do future climate change affect agriculture? (2) Geoengineering scenario – Case Study - China 31

Observations – Meteorology Temperature Precipitation Solar Radiation Summer Winter (2) Geoengineering scenario – Case Study - China 32

Observations – Agricultural Production Rice Production (Gt) ( average) Maize Production (Gt) ( average) Spring Wheat Production (Gt) ( average) Winter Wheat Production (Gt) ( average) (2) Geoengineering scenario – Case Study - China 33

Observations – Agricultural Yield and Practice (2) Geoengineering scenario – Case Study - China 34

Crop model evaluation - Rice (2) Geoengineering scenario – Case Study - China [Xia et al., 2013] 35

Crop model evaluation - Maize (2) Geoengineering scenario – Case Study - China [Xia et al., 2014] 36

Rice Maize The end of G2 geoengineering (2) Geoengineering scenario – Case Study - China III. How do future climate change affect agriculture? [Xia et al., 2014] 37

Crop yield changes under simulated G2 geoengineering (Year 36-50) compared with the same period of 1pctCO2. (2) Geoengineering scenario – Case Study - China [Xia et al., 2014] 38

Rice Maize G2 GeoengineeringEnd of G2 Geoengineering (2) Geoengineering scenario – Case Study - China [Xia et al., 2014] 39

Rice Maize CO 2 fertilization effect: raises rice production by 8.6 Mt and compensates the negative impacts from other climate changes due to G2 on rice. contributes 42.4% of the maize production increase compared with 1pctCO2 (2) Geoengineering scenario – Case Study - China [Xia et al., 2014] III. How do future climate change affect agriculture? 40

(G2) have no significant effect on Chinese rice production, while without CO 2 fertilizer effect, Chinese rice production would drop 11.6 Mt (11.6%) as compared to 1pctCO2; (G2) raise rice production by 5.2 Mt after the termination of G2 ; (G2) would increase Chinese maize production by 18.1 Mt (13.9%) compared with 1pctCO2 and CO 2 fertilization effect contributes to 42% of this increasing. (G2) decrease Chinese maize production to the level of 1pctCO2 after the termination of G2. Using one crop model, Geoengineering would: III. How do future climate change affect agriculture? (2) Geoengineering scenario – Case Study - China 41

This would be only 0.03% of the current world arsenal. Scenario: Weapons dropped on the 50 targets in each country that would produce the maximum smoke. 5 Tg of smoke injected into the upper troposphere, accounting for fuel loading, emission factors and rainout. What would be the consequences of a regional nuclear war using kT (Hiroshima-size) weapons between India and Pakistan? III. How do future climate change affect agriculture? (3) A regional nuclear war scenario 42

Daily smoke loading from one ensemble member. Absorption optical depth of 0.1 means that 90% of radiation reaches the surface. (3) A regional nuclear war scenario 43

[Mills et al., 2014] Climate Changes – Regional Nuclear War 44

“Our results show that this period of no food production needs to be extended by many years, making the impacts of nuclear winter even worse than previously thought.” III. How do future climate change affect agriculture? (3) A regional nuclear war scenario [Robock et al., 2007] 45

With 1°C and 2°C higher temperature, rice production forced by GISS ModelE output in the first three years increased 6 Mt and 10 Mt, respectively, but was still 17% and 13% less then control run. III. How do future climate change affect agriculture? [Xia et al., 2013] 46

An additional 50 kg/ha fertilizer can compensate the negative impact on rice production. After moving rice planting region to the South, Chinese rice production increased 8-12 Mt under the nuclear war scenario. [Xia et al., 2013] III. How do future climate change affect agriculture? 47

IV. How would agriculture system feedback on climate system Make changes in: Energy Balance Albedo Latent Heat Sensible Heat Chemical emission Temperature Precipitation, Pressure Temperature 48

IV. How would agriculture system feedback on climate system [Lyons et al., 1996] Satellite observations for south-western Australia. The native vegetation is a woodland called mallee. The topography of the region is duplex mallee soils – sand overlying clay. 49

IV. How would agriculture system feedback on climate system [Lyons et al., 1996] Satellite observations for south-western Australia. The native vegetation is a woodland called mallee. The topography of the region is duplex mallee soils – sand overlying clay. 50

IV. How would agriculture system feedback on climate system Annual mean surface albedo change caused by anthropogenic vegetation changes. ( MODIS) The increase in the surface albedo at mid-latitudes in the northern hemisphere is a result of deforestation for agricultural activity. The increase of the annual mean surface albedo is more than 0.1 in certain areas. In some areas the conversion of grassland to cropland has reduced the surface albedo, but the effect is of smaller magnitude than in regions with deforestation. [Myhre et al., 2005] 51

IV. How would agriculture system feedback on climate system [Levis et al., 2012] Model simulation using CESM-CLM-crop with active atmospheric model. CTRL is model simulation with crop model turned off, CROP is with crop model turned on, LateP is with crop model turned on and using the latest date for planting. With crop model turned on, simulated leaf area index reduces in winter and increases in the growing season, which reduce the latent heat flux but not around peak LAI. Simulated 850-hPa wind pattern is slightly changed with crop model turned on and therefore simulated precipitation reduced in Midwestern North America. 52

IV. How agriculture system feedback on climate system Chemical emissions from agriculture [IPCC, 2006] 53

NH 3 /NH 4 + N2N2 Nitrogen Fixation Fertilizer NO 2 - NO 3 - Nitrification N2ON2O N2N2 Denitrification Volatilization Plant uptake Leaching N2ON2ON2ON2ON2N2 NH 3 Stratosphere Ozone depletion Troposphere More UV Tropics IV. How agriculture system feedback on climate system 54