Confronting the Food Security Threats from Climate Change -- Grand Junction

Food Security Challenges in the 21st Century

Climate Change, Economic Development, Resource Scarcity, and Population Growth

Gerald C. Nelson

Professor Emeritus, University of Illinois, Urbana-Champaign

Presentation at Mesa County Library, August 4, 2014

Welcome to the Anthropocene!

Economist, May 26, 1011

Food security challenges are unprecedented. By 2050 …• Many more people in developing countries

• Between 2000 and 2050, 50 percent increase globally; almost all in developing countries

• With higher incomes, they will demand more food quantity and higher quality

• The double burden of malnutrition – obesity and hunger side-by-side – will be a much more serious problem

• Resource scarcity (water quantity and quality, soil, clean air, biodiversity) becoming more serious

• Climate change – a threat multiplier with uncertain outcomes• Reduced productivity of existing varieties of plants and animals and cropping systems

in many places

Climate change has already affected agriculture

Chinese rice production has shifted north

Coffee production is shifting up the mountains

Pasta is Threatened because of Durum Wheat Sensitivity to Temperature

Climate change has already offset research productivity in many places, except US

Estimated net impact of climate trends for 1980-2008 on crop yields, divided by the overall yield trend

Source: Figure 3 in Lobell, Schlenker, and Costa-Roberts (2011).

But the future impacts of climate change on agriculture could be much greater

And with widely varying outcomes

Precipitation change (mm), 2000-2050

MIROC climate model, RCP 8.5

GDFI climate model, RCP 8.5


GDFI climate model, RCP 8.5

Temperature change (°C), average maximum, 2000-2050

Climate Change from Anthropogenic GHG Emissions, 2000-2050

Rainfed corn yield change, 2000-2050 Irrigated rice yield change, 2000-2050


GFDI climate model, RCP 8.5 GFDI climate model, RCP 8.5


And it gets much worse after 2050

Year Developed DevelopingRainfed Irrigated Rainfed Irrigated

2030 -1.3 -4.3 -2.2 -9.02050 -4.2 -6.8 -4.1 -12.02080 -14.3 -29.0 -18.6 -29.0

Climate change impacts on wheat yields with 2030, 2050, and 2080 climate (percent change from 2000)

Source: Nelson et al, 2010.

High productivity irrigated wheat in developing countries affected most strongly

FAO foresees modest cereal yield improvements to 2050 (but ignores climate change)(kg/ha left-axis, growth percent per annum right-axis)

0.0

0.5

1.0

1.5

2.0

2.5

0

500

1,000

1,500

2,000

2,500

3,000

3,500

4,000

4,500

5,000

sub-SaharanAfrica

South Asia Near East & N.Africa

Latin America Developingcountries

World Developedcountries

East Asia

Pe

rce

nt

pe

r an

nu

m

Kt/

ha

2006 2050 Growth

Source: Alexandratos and Bruinsma (2012).

0.65% p.a. vs. 2% p.a. 1960-2005

Land use change continues in Latin America and Sub-Saharan Africa(million hectares left-axis, percent change 2005/07 - 2050 right-axis)

11.0

24.2

21.1

0.1

3.4

0

4

8

12

16

20

24

28

32

0

20

40

60

80

100

120

140

160

Developing countries Latin America sub-Saharan Africa Near East & N. Africa East Asia South Asia Developed countries

Pe

rce

nt

chan

ge 2

00

5/7

-20

50

Mill

ion

he

ctar

es

Irrigated land change, million hectare (left-axis) Rain-fed land change, million hectare (left-axis) Percent change between 2005/07-2050 (right-axis)

Source: Alexandratos and Bruinsma (2012).

Food Security, Farming, and Climate Change to 2050: Key Findings• Agricultural prices increase with GDP and population growth

• Prices increase even more because of climate change


Crop prices declined throughout the 20th

century

Source: Figure 2.1 in Nelson et al, 2010.

Income and population growth drive prices higher in the 21st century(price increase (%), 2010 – 2050, Baseline economy and demography)


Climate change will cause greater price increases (price increase (%), 2010 – 2050, Baseline economy and demography)

Minimum and maximum effect from four climate

scenarios


Pessimistic scenario

Perfectmitigation

1,800

2,000

2,200

2,400

2,600

2,800

3,000

3,200

3,400

3,600

Kca

ls/d

ay

Optimistic scenarioDevelopedcountries

All developingcountries

Low-income developing countries

Income and population growth are more ‘important’ than climate change to 2050 (average kilocalories per day)


Three main food security messages for today’s low income countries• Sustainable development is a more important priority than climate

change adaptation today

• Prepare today for higher temperatures and changes in precipitation in all sectors tomorrow • Invest more in capacity to adapt agriculture

• Keep international trade relatively free from barriers

• Improve domestic policies that support agriculture

• Collect better data today and tomorrow on existing situation and practices• Weather, land cover, water availability, prices, practices

What is missing in our climate change results? The Lamppost Problem• The models used to analyze the

agricultural effects of climate change don’t include effects of• Increasing ozone

• Increasing extreme events

• Increasing pest and disease pressure

• These could swamp the negative effects already quantified, making the challenges much more difficult, even over the next 35 years to 2050.

Thanks!

Confronting the Food Security Threats from Climate Change -- Grand Junction

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