The New Farmer’s AlmanacAgriculture and Climate Change

Anne Royer & Tomomi SuwaGK-12 Fall Workshop

October 3, 2012

How will climate change impact farmers?

• Understanding the difference between climate and weather

• Specific predictions of climate change• Using real long-term data to understand

how predicted changes may affect crops

Weather vs. Climate

WEATHER• Local• Short-term (days to

months)• Prediction based on

current conditions• Current atmospheric

conditions

CLIMATE• Regional or broader• Long-term (years to

decades)• Prediction based on less

labile long-term trends• Big picture of how

atmosphere behaves

Illustrating weather vs. climatehttp://www.climate.gov/#education

HOW will the climate change?Everywhere:• Warmer temperatures• Higher annual precipitation• More rain in winter and spring• Increase in extreme weather events – less

predictable weatherWhat will this mean for agriculture?

HOW will the climate change?In Michigan:• Warmer temperatures• Higher annual precipitation• More rain in winter and spring• Increase in extreme weather events – less

predictable weatherWhat will this mean for agriculture?

HOW will the climate change?In Michigan:• Warmer temperatures• Higher annual precipitation• More rain in winter and spring• Increase in extreme weather events – less

predictable weatherWhat will this mean for agriculture?

Effects of Climate Change on Agriculture

LTER - Since 1987

Corn Wheat Soybean

Biomass over time

1990 1995 2000 2005 20100

200

400

600

800

1000

1200

1400

1600

Corn

1991 1996 2001 2006 20110

100200300400500600700800900

Wheat

1985 1990 1995 2000 2005 2010 20150

200

400

600

800

1000

1200

Soy

Biom

ass (

g/m

2)

Research Questions

Does climate change affect crop yields?Any guesses?

Hypothesis and predictionsIf (hypothesis) then (prediction)

Data we have:-Biomass (g/m2)-Total precipitation (May – Sept)-Average soil moisture (May-Sept)-Average temperature(May-Sept)

Does climate change affect crop yields?

Hypothesis: Educated guess, general statementPrediction: What you think will happen, more specific

e.g. If climate change affect crop yield, then increased soil moisture will

increase crop production.

MethodsPrediction: Increased soil moisture will increase biomass

Soil Moisture (%)

Bio

mas

s (g

/m2 )

MethodsTitle: The Effect of the independent variable on the

dependent variable

Independent Var (unit)

Dep

ende

nt V

ar (u

nit)

Cause: Something that is affecting the dependent variable but not affected by dependent variable.

Effect: Something that might be affected by the change in the independent variable

Plotting in Excel

e.g. moisture vs. precipitation

Let’s analyze the data!

• Divide into 3 groups (corn, wheat, soy)• Spend 15 min plotting graphs• Share the results with the class

• Plot:– Biomass vs Precipitation (mm)– Biomass vs Soil Moisture (%)– Biomass vs Temperature (°C)

Results

200 300 400 500 600 7000

200

400

600

800

1000

1200

1400

f(x) = − 0.237913362782616 x + 1320.70364992666R² = 0.0296733212008734

Corn

200 300 400 500 600 700

f(x) = 0.445060051903132 x + 421.850972122727R² = 0.146406562232492

Wheat

200 300 400 500 600 700

f(x) = − 0.510060688953362 x + 826.514769862717R² = 0.0294168233794435

Soy

Effects of Precipitation on CropsBi

omas

s (g/

m2)

Accumulative Precipitation between May - Sept (mm)

8 9 10 11 12 13 14 15 16 17

f(x) = 7.46643113869275 x + 487.939432163857R² = 0.00140864281336817

Soy

8 9 10 11 12 13 14 15 16 17

f(x) = 35.2648542727135 x + 122.487642611366R² = 0.380962407189675

Wheat

8 9 10 11 12 13 14 15 16 170

200400600800

1000120014001600

f(x) = − 45.1440389076482 x + 1803.41330971116R² = 0.191453435399398

Corn

Effects of Soil Moisture on Crops

Soil Moisture (%) Soil Moisture (%) Soil Moisture (%)

Biom

ass (

g/m

2)

16 16.5 17 17.5 18 18.5 19 19.5 200

500

1000

1500f(x) = 144.651179798355 x − 1481.42575948191R² = 0.483413991894531

Corn

16 16.5 17 17.5 18 18.5 19 19.5 20

f(x) = − 1.99460414805363 x + 668.765737423689R² = 0.000199192756034305

Wheat

16 16.5 17 17.5 18 18.5 19 19.5 20

f(x) = 44.7512903859991 x − 209.219849378496R² = 0.0280008252645215

Soy

Effects of Temperature on Crops

200 300 400 500 600 700 8000

2

4

6

8

10

12

f(x) = NaN x + NaNR² = 0 Moisture vs. Precipitation

9 10 11 12 13 14 15 16 1715.5

1616.5

1717.5

1818.5

1919.5

2020.5

f(x) = − 0.176265753576823 x + 20.8647961946407R² = 0.145703308613617

Moisture vs. Temp

16.5 17 17.5 18 18.5 19 19.5 20 20.50

100

200

300

400

500

600

700

f(x) = − 25.4625593382805 x + 910.108947488661R² = 0.0579099465247263

Precipitation vs. Temp

Precipitation (mm)

Prec

ipita

tion

(mm

)

Soil

Moi

stur

e (%

)

Soil Moisture (%)

Tem

pera

ture

(°C)

Temperature (°C)

Hypothesis: Climate change will increase yields

RESULTS (supported predictions in red)• Corn– Increased temperature, increased yield– Increased soil moisture, decreased yield

• Soy– Increased precipitation, slightly decreased yield

• Wheat– Increased soil moisture, increased yield– Increased precipitation, increased yield

Hypothesis: Climate change will increase MI yields

Conclusions• Hypothesis supported for corn and wheat, but

not soy• Climate change is likely to have different effects

on different crops• Caveats:

• May be unmeasured correlated variables• Simplified data –e.g., we didn’t control for

when and how the precipitation arrived

Wrap-up

• Will climate change increase yields?• IT DEPENDS!• Weather vs. climate: we’re using– variation in WEATHER – to predict the result of changes in CLIMATE

Helpful resources• http://www.nasa.gov/mission_pages/noaa-n/

climate/index.html (NASA explanation of climate vs. weather)

• http://www.climate.gov/#education (NOAA interactive climate change graphs)

• http://www.msue.msu.edu/kr/default.cfm?node_id=59525 (MSU extension pamphlets)