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Confronting the Food Security Threats from Climate Change -- Grand Junction
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Transcript of 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
Page 3
Climate change has already affected agriculture
Chinese rice production has shifted north
Page 5
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
Page 8
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
MIROC 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
MIROC climate model, RCP 8.5
GFDI climate model, RCP 8.5 GFDI climate model, RCP 8.5
MIROC 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
Source: Nelson et al, 2010.
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)
Source: Nelson et al, 2010.
Climate change will cause greater price increases (price increase (%), 2010 – 2050, Baseline economy and demography)
Minimum and maximum effect from four climate
scenarios
Source: Nelson et al, 2010.
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)
Source: Nelson et al, 2010.
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!