Impacts of Climate Change
on Agriculture
Assembled by Brian Viner and Gene Takle
(Mt/Ag/EnSc/EnSt 404/504 - Global Change)
Agriculture Impacts
Questions to consider
The U.S. Climate Change Science Program (CCSP) focused on the
following questions:
What factors influencing agriculture, land resources, water resources,
and biodiversity in the United States are sensitive to climate and
climate change?
How could changes in climate exacerbate or ameliorate stresses on
agriculture, land resources, water resources, and biodiversity?
What are the indicators of these stresses?
(Mt/Ag/EnSc/EnSt 404/504 - Global Change)
Agriculture Impacts
Potential Agricultural-Related Impacts
from Climate Change
• Droughts and low water-tables leading to water
stress
• Transport of water to other locations
• Warmer temps leading to more pests and diseases
• Changing seasons will lead to different crop growth.
• Soil temperatures will remain warmer
(Mt/Ag/EnSc/EnSt 404/504 - Global Change)
Agriculture Impacts
So what if CO2 goes up?
Carbon dioxide is also the source of carbon for photosynthesis,
and consequently for 99% of all life.
CO2 + H2O + light  O2 + organic C + chemical energy
(Mt/Ag/EnSc/EnSt 404/504 - Global Change)
Agriculture Impacts
Impacts
biophysical impacts:
• physiological effects on crops, pasture, forests and livestock
(quantity, quality);
• changes in land, soil and water resources (quantity, quality);
• increased weed and pest challenges;
socio-economic impacts:
• decline in yields and production;
• reduced marginal GDP from agriculture;
• fluctuations in world market prices;
• changes in geographical distribution of trade regimes;
• increased number of people at risk of hunger and food
insecurity;
• migration and civil unrest.
(Mt/Ag/EnSc/EnSt 404/504 - Global Change)
Agriculture Impacts
More impacts
• Food production is projected to benefit from a warmer climate,
but there probably will be strong regional effects.
• Additional CO2 is expected to improve crop yield and biomass
production
• The U.S. Great Plains/Canadian Prairies are expected to be
particularly vulnerable.
• Crops that are currently near climate thresholds (e.g., wine
grapes in California) are likely to suffer decreases in yields,
quality, or both.
• Climate change is expected to improve growing conditions for
some crops that are limited by length of growing season and
temperature. (e.g. fruit production in the Great Lakes region and
eastern Canada).
(Mt/Ag/EnSc/EnSt 404/504 - Global Change)
Agriculture Impacts
Warmer winters may benefit European wine grapes (V.
vinifera) by reducing winter damage to roots and vines
Geneva Weather Data
10
0
Coldest
Winter
Low
-10
Temp ÞF
Critical Temp
Vine Damage
-20
-30
1940
1950
1960
1970
1980
1990
2000
Year
Source: A. Lakso, Cornell
(Mt/Ag/EnSc/EnSt 404/504 - Global Change)
Agriculture Impacts
D. Herzmann, Iowa Environmental Mesonet
(Mt/Ag/EnSc/EnSt 404/504 - Global Change)
Agriculture Impacts
D. Herzmann, Iowa Environmental Mesonet
(Mt/Ag/EnSc/EnSt 404/504 - Global Change)
Agriculture Impacts
D. Herzmann, Iowa Environmental Mesonet
(Mt/Ag/EnSc/EnSt 404/504 - Global Change)
Agriculture Impacts
Fewer precipitation events
More intense precipitation events
Increased occurrence of damaging floods
D. Herzmann, Iowa Environmental Mesonet
(Mt/Ag/EnSc/EnSt 404/504 - Global Change)
Agriculture Impacts
Potential types of adaptation
•
•
•
•
Seasonal changes and sowing dates
Different variety or species
Water supply and irrigation system
Other inputs (fertilizer, tillage methods, grain drying,
other field operations)
• New crop varieties
(Mt/Ag/EnSc/EnSt 404/504 - Global Change)
Agriculture Impacts
Sensitivity of Maize Yield to Climate Change
Red= without adaptation
Black=with adaptation (change planting date, cultivar, use of irrigation)
IPCC, 2007:Climate Change 2007: Impacts, Adaptation and Vulnerability. Contribution of Working Group II to the Fourth Assessment
Report of the Intergovernmental Panel on Climate Change, M.L. Parry, O.F. Canziani, J.P. Palutikof, P.J. van der Linden and C.E.
Hanson, Eds., Cambridge University Press, Cambridge, UK, 976pp. Chapter 5.
(Mt/Ag/EnSc/EnSt 404/504 - Global Change)
Agriculture Impacts
(Mt/Ag/EnSc/EnSt 404/504 - Global Change)
Agriculture Impacts
Food costs
(Mt/Ag/EnSc/EnSt 404/504 - Global Change)
Agriculture Impacts
(Mt/Ag/EnSc/EnSt 404/504 - Global Change)
Agriculture Impacts
Reasons for Crop Increases
• Longer growing season
• Warmer spring soil temperatures
• Modest or no increase in summer daily
maximum temperatures
• Increase in nighttime temperatures
• Reduced risk of late frost in spring or early
frost in fall
• More freeze-thaw cycles that will recharge
soil moisture in winter
(Mt/Ag/EnSc/EnSt 404/504 - Global Change)
Agriculture Impacts
Reasons for Crop Increases
• More precipitation
• More soil moisture
• Higher dew-point temperatures reduces
moisture stress
• Increased carbon uptake by crops
• Higher CO2 increases the water-use
efficiency of crops
(Mt/Ag/EnSc/EnSt 404/504 - Global Change)
Agriculture Impacts
Reasons for Crop Decreases
• More precipitation extremes
• More rain events bring heavy rain
• More droughts
• More floods
• More over-wintering pests
• More pathogens due to higher humidity
• More vigorous weed growth
• More efficient water use => less cooling
(Mt/Ag/EnSc/EnSt 404/504 - Global Change)
Agriculture Impacts
Which Cow Will Be Affected More by
the Sun?
(Mt/Ag/EnSc/EnSt 404/504 - Global Change)
Agriculture Impacts
Example of the
Interaction of
Temperature and
Humidity in
Determining Heat
Stress Potential in
Dairy Cattle
(Mt/Ag/EnSc/EnSt 404/504 - Global Change)
Agriculture Impacts
How might Agriculture be Affected by
Mitigation Legislation?
Agriculture may need to reduce emissions because it
releases substantial amounts of methane, nitrous
oxide, and carbon dioxide.
• 50% of total methane, 70% of nitrous oxide, and 20%
of carbon dioxide
(Mt/Ag/EnSc/EnSt 404/504 - Global Change)
Agriculture Impacts
How might Agriculture be Affected by
Mitigation Legislation?
Agriculture may enhance its absorption of GHGE by
creating or expanding sinks.
• Management practices can increase soil carbon
retention
• Land retirement (conversion to native vegetation)
• Residue management
• Less-intensive tillage
• Land use conversion to pasture or forest
• Restoration of degraded soils
(Mt/Ag/EnSc/EnSt 404/504 - Global Change)
Agriculture Impacts
How might Agriculture be Affected by
Mitigation Legislation?
Agriculture may provide substitute products which
replace fossil fuel intensive products.
- Cotton and other fibers can also be used to
reduce petroleum-based synthetics
Agriculture may find itself operating in a world where
commodity and input prices have been altered by
GHG related policies.
- Increasing fuel taxes and transportation costs
will be passed to the consumer
(Mt/Ag/EnSc/EnSt 404/504 - Global Change)
Agriculture Impacts
Information Taken From:
• IPCC 4th Assessment Report
• Climateandfarming.org
(Mt/Ag/EnSc/EnSt 404/504 - Global Change)
Agriculture Impacts
Impacts of Climate Change
on Agriculture
END
(Mt/Ag/EnSc/EnSt 404/504 - Global Change)
Agriculture Impacts