Climate Impacts on Agriculture
For Climatology Class 11/6/2014
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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?
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I. Agriculture is essential
On average, every day, each person
on the planet consumes:
It is a challenge to feed the world in 2050
(1)
(2)
(3)
(4)
Food demand increasing
Food distributed unevenly
Waste
Climate changes
[Elert, 2014]
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I. Agriculture is essential
(1) Food Demand is Increasing
(under assumption of consumption patterns do not change)
http://ccafs.cgiar.org/bigfacts2014/#theme=food-security
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I. Agriculture is essential
[Elert, 2014]
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I. Agriculture is essential
In developing countries, calories per person is increasing with time
[Alexandratos and Bruinsma, 2012]
http://ccafs.cgiar.org/bigfacts2014/#theme=food-security
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I. Agriculture is essential
(2 ) Food distributed unevenly
http://www.fao.org/economic/ess
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Kevin Carter, March 1993, Sudan
A starving toddler trying to reach a feeding center when a hooded vulture landed nearby
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I. Agriculture is essential
(3) Waste
Food Waste
https://www.youtube.com/watch?v=IoCVrkcaH6Q
https://www.youtube.com/watch?v=Md3ddmtja6s
Let’s calculate our carbon food print:
http://coolclimate.berkeley.edu/carboncalculator
http://www.foodemissions.com/foodemissions/Calculator.aspx
http://ccafs.cgiar.org/bigfacts2014/#theme=food-security
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I. Agriculture is essential
Global Temperature Relative to 1800-1900
(4) Global climate impacts food production
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(IPCC, 2007)
I. Agriculture is essential
(4) Global climate impacts food production
 Photosynthesis
6𝐶𝑂2 + 6𝐻2 𝑂
ℎ𝑣
𝐶6 𝐻12 𝑂6 + 6𝑂2
 Respiration
𝐶6 𝐻12 𝑂6 + 6𝑂2 → 6𝐶𝑂2 + 6𝐻2 𝑂 + ℎ𝑣
 Transpiration
•
•
•
•
•
Movement of minerals and sugars
Cooling
Turgor pressure
Osmotic pressure
Capillary action
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II. How does climate affect agriculture
Climate Factors
24 Solar Terms:
Autumnal equinox
Temperature
Precipitation
Winter solstice
Summer solstice
Solar radiation
CO2
Vernal equinox
O3
(Liu A et al. 139 BCE)
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II. How does climate affect agriculture
Climate Factors - Temperature
Rice
Wheat
(Nishiyama et al., 1976)
(Porter and Gawith, 1999)
Maize
(Schlenker and Roberts, 2006)
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II. How does climate affect agriculture
Climate Factors - Precipitation
Wheat
Rice
Maize
Cotton
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[Jalota et al., 2007]
II. How does climate affect agriculture
Climate Factors – Solar Radiation
Simulated direct light
Observed direct light
Simulated diffuse light
Observed diffuse light
PAR(μmol m-2 s-1)
[Mercado et al., 2009]
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II. How does climate affect agriculture
Climate Factors – CO2
CO2 fertilization effect
[Leadley and Drake 1993]
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[Dayton, 2014]
II. How does climate affect agriculture
Total crop production loss (CPL)
Climate Factors –O3
2000
2030, A2
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[Avenery et al., 2011a, b]
III. How do future climate change affect agriculture?
• Crop Model
Statistic Model
Dynamic Model
• Agriculture Data
Crop distribution
Planting date
Cultivars
• Climate Forcing
Irrigation
Observation
Fertilizer
Climate Model Simulation
Pesticide
Crop
Model
Soil
Property
Agriculture
Data
Climate
Forcing
• Soil properties
Physical properties
Chemical properties
Predict future climate impact on
agriculture
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III. How do future climate change affect agriculture?
What is Dynamic Crop model? Example: DSSAT
Soil-PlantAtmosphere
Weather
Main
Program
Management
Soil
Plant
Daily Tmax
Planting
Dynamics
Maize
Daily Tmin
Harvesting
Water
Wheat
Irrigation
N
Rice
Fertilizer
P
Potato
Residue
Organic
matter
Daily Precip.
Daily solar
radiation
CO2
Other
crops
Tillage
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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)
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[Lobell et al., 2008]
(1) Negative Impact:
SAF-maize
SAF-wheat
(2) Large uncertainties
SAS-groundnut
SAF-sorghum
(3) No changes
WAS-wheat
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[Lobell et al., 2008]
III. How do future climate change affect agriculture?
(1) Global Warming scenario – Case study – Dynamics Crop Model
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
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[Rosenzweig, 2014]
members), and soy (35 ensemble members).
III. How do future climate change affect agriculture?
(1) Global Warming scenario – Case study – Dynamics Crop Model
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)
CO2 effects for maize, wheat,
rice, and soy; bars show
range of all GCM
combinations with CO2
effects. GEPIC, GAEZ-IMAGE,
and LPJ-GUESS only
contributed one GCM
without CO2 effects. 24
[Rosenzweig, 2014]
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 CO2 concentration in the atmosphere … damming the ocean … reducing the
incoming solar radiation …“[Robock et al., 2008]
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III. How do future climate change affect agriculture?
Solar Radiation Management
Space-based
reflectors
Stratospheric
aerosols
Tropopause
Cloud
brightening
Surface albedo
modification
Earth surface
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III. How do future climate change affect agriculture?
(2) Geoengineering scenario
[Robock et al., 2008]
“Simulated geoengineering reduced precipitation over wide regions, condemning
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hundreds of millions of people to drought.”
[Robock, 2008]
GeoMIP
– The Geoengineering Modeling Intercomparison Project
- 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.
(Kravitz et al., 2011)
G2: In combination with 1% CO2 increase per year, gradually reduce the solar
constant to balance the changing radiative forcing.
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Global Temperature Changes – G2 Geoengineering
dotted lines are +1%/yr CO2
solid lines are G2
[Jones et al., 2014]
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Global Precipitation Changes – G2 Geoengineering
dotted lines are +1%/yr CO2
solid lines are G2
[Jones et al., 2014]
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III. How do future climate change affect agriculture?
(2) Geoengineering scenario – Case Study - China
(www.fao.org)
World population
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(2) Geoengineering scenario
– Case Study - China
Observations – Meteorology
Summer
Winter
Temperature
Precipitation
Solar Radiation
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(2) Geoengineering scenario
– Case Study - China
Observations – Agricultural Production
Rice Production (Gt) (1978-2008 average)
Winter Wheat Production (Gt) (1978-2008 average)
Maize Production (Gt) (1978-2008 average)
Spring Wheat Production (Gt) (1978-2008 average)
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(2) Geoengineering scenario
– Case Study - China
Observations – Agricultural Yield and Practice
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(2) Geoengineering scenario
– Case Study - China
Crop model evaluation - Rice
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[Xia et al., 2013]
(2) Geoengineering scenario
– Case Study - China
Crop model evaluation - Maize
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[Xia et al., 2014]
III. How do future climate change affect agriculture?
Rice
Maize
The end of G2 geoengineering
(2) Geoengineering
scenario
– Case Study
- China
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[Xia et al., 2014]
(2) Geoengineering scenario – Case Study - China
Crop yield changes under simulated G2 geoengineering (Year 36-50)
compared with the same period of 1pctCO2.
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[Xia et al., 2014]
(2) Geoengineering
scenario
– Case Study
- China
G2 Geoengineering
End of G2 Geoengineering
Rice
Maize
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[Xia et al., 2014]
III. How do future climate change affect agriculture?
(2) Geoengineering scenario
– Case Study - China
Rice
Maize
CO2 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
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[Xia et al., 2014]
III. How do future climate change affect agriculture?
(2) Geoengineering scenario – Case Study - China
Using one crop model, Geoengineering would:
• (G2) have no significant effect on Chinese rice production, while without
CO2 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 CO2 fertilization effect contributes to 42%
of this increasing.
• (G2) decrease Chinese maize production to the level of 1pctCO2 after
the termination of G2.
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III. How do future climate change affect agriculture?
(3) A regional nuclear war scenario
What would be the consequences of a regional nuclear war
using 100 15-kT (Hiroshima-size) weapons between India and
Pakistan?
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.
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(3) A regional nuclear war scenario
Daily smoke loading from one ensemble member.
Absorption optical depth of 0.1 means that 90% of radiation reaches the surface.
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Climate Changes – Regional Nuclear War
[Mills et al., 2014]
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III. How do future climate change affect agriculture?
(3) A regional nuclear war scenario
[Robock et al., 2007]
“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.”
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III. How do future climate change affect agriculture?
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.
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[Xia et al., 2013]
III. How do future climate change affect agriculture?
An additional 50 kg/ha fertilizer can compensate the negative impact on
rice production. After moving rice planting region to the South, Chinese rice
47 2013]
production increased 8-12 Mt under the nuclear war scenario.
[Xia et al.,
IV. How would agriculture system feedback on climate system
Make changes in:
Energy Balance
• Albedo
• Latent Heat
• Sensible Heat
Precipitation, Pressure
Temperature
• Chemical emission
Temperature
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http://www.cesm.ucar.edu/models/clm/
IV. How would agriculture system feedback on climate system
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.
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[Lyons et al., 1996]
IV. How would agriculture system feedback on climate system
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.
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[Lyons et al., 1996]
IV. How would agriculture system feedback on climate system
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]
Annual mean surface albedo change caused by anthropogenic
vegetation changes. (2001-2004 MODIS)
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IV. How would agriculture system feedback on climate system
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.
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[Levis et al., 2012]
IV. How agriculture system feedback on climate system
Chemical emissions from agriculture
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[IPCC, 2006]
IV. How agriculture system feedback on climate system
Ozone depletion
More UV
Stratosphere
Troposphere
Tropics
NH3
N2O
N2O
N2
N2O
N2
N2
Fertilizer
Nitrogen
Fixation
Volatilization
Plant uptake
NH3/NH4+
NO2-
NO3Nitrification
Leaching
Leaching
Denitrification
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