From our climate panel in Grand Junction on August 4:
Our Forest, Our Water, Our Land: Local Impacts on Climate Change. Sponsored by Conservation Colorado, Mesa County Library, Math & Science Center
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Confronting the Food Security Threats from Climate Change -- Grand Junction
1. 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
3. Food security challenges are unprecedented.
By 2050 โฆ
โข Many more people in developing countries
โข Between 2000 and 2050, 50 percent increase globally; almost all in developing
countries
โข With higher incomes, they will demand more food quantity and higher
quality
โข The double burden of malnutrition โ obesity and hunger side-by-side โ will
be a much more serious problem
โข Resource scarcity (water quantity and quality, soil, clean air, biodiversity)
becoming more serious
โข Climate change โ a threat multiplier with uncertain outcomes
โข Reduced productivity of existing varieties of plants and animals and cropping systems
in many places
Page 3
8. 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 Page Costa-8
Roberts (2011).
9. But the future impacts of climate
change on agriculture could be much
greater
And with widely varying outcomes
12. And it gets much worse after 2050
Climate change impacts on wheat yields with 2030, 2050, and
2080 climate (percent change from 2000)
Year Developed Developing
Rainfed Irrigated Rainfed Irrigated
2030 -1.3 -4.3 -2.2 -9.0
2050 -4.2 -6.8 -4.1 -12.0
2080 -14.3 -29.0 -18.6 -29.0
Source: Nelson et al, 2010.
High productivity irrigated
wheat in developing
countries affected most
strongly
13. FAO foresees modest cereal yield improvements
to 2050 (but ignores climate change)
(kg/ha left-axis, growth percent per annum right-axis)
2.5
2.0
1.5
1.0
0.5
0.0
5,000
4,500
4,000
3,500
3,000
2,500
2,000
1,500
1,000
500
0
sub-Saharan
Africa
South Asia Near East & N.
Africa
Latin America Developing
countries
World Developed
countries
East Asia
Percent per annum
Kt/ha
2006 2050 Growth
Source: Alexandratos and Bruinsma (2012).
0.65% p.a. vs. 2% p.a. 1960-2005
14. 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
32
28
24
20
16
12
8
4
0
160
140
120
100
80
60
40
20
0
Developing countries Latin America sub-Saharan Africa Near East & N. Africa East Asia South Asia Developed countries
Percent change 2005/7-2050
Million hectares
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).
15. Food Security, Farming, and Climate Change
to 2050: Key Findings
โข Agricultural prices increase with GDP and population growth
โข Prices increase even more because of climate change
Source: Nelson et al, 2010.
16. Crop prices declined throughout the 20th
century
Source: Figure 2.1 in Nelson et al, 2010.
17. Income and population growth drive prices higher
in the 21st century
(price increase (%), 2010 โ 2050, Baseline economy and demography)
Source: Nelson et al, 2010.
18. Climate change will cause greater price increases
(price increase (%), 2010 โ 2050, Baseline economy and demography)
Minimum and maximum
effect from four climate
scenarios
Source: Nelson et al, 2010.
19. Income and population growth are more โimportantโ than climate
change to 2050 (average kilocalories per day)
Pessimistic scenario
Perfect
mitigation
3,600
3,400
3,200
3,000
2,800
2,600
2,400
2,200
2,000
1,800
Kcals/day
Optimistic scenario
Developed
countries
All developing
countries
Low-income developing
countries
Source: Nelson et al, 2010.
20. Three main food security messages for
todayโs low income countries
โข Sustainable development is a more important priority than climate
change adaptation today
โข Prepare today for higher temperatures and changes in precipitation in
all sectors tomorrow
โข Invest more in capacity to adapt agriculture
โข Keep international trade relatively free from barriers
โข Improve domestic policies that support agriculture
โข Collect better data today and tomorrow on existing situation and
practices
โข Weather, land cover, water availability, prices, practices
21. What is missing in our climate change results?
The Lamppost Problem
โข The models used to analyze the
agricultural effects of climate change
donโt include effects of
โข Increasing ozone
โข Increasing extreme events
โข Increasing pest and disease pressure
โข These could swamp the negative
effects already quantified, making the
challenges much more difficult, even
over the next 35 years to 2050.
Obvious changes โ converting forested land to agriculture; damming rivers, to less obvious changes โ massive additions of nitrogen to the nitrogen cycle, loss of species, larger brain sizes for mice.
Source: Downscaled data from AR5 model runs,
Price increases with perfect mitigation and baseline are
Maize โ 52%
Rice โ 29%
Wheat โ 25%
Maize price mean increase is 101 % higher; max is 131, min is 83
Rice price mean increase is 55; max is 57, min is 53
Wheat price mean increase is 54; max is 66, min is 45
All these are for the baseline overall scenario
Key messages
With income per capita growth rates in the optimistic scenario, average kcals per day growth very rapidly in the developing countries.
Climate change reduces calorie availability, partially offsetting the benefits from income growth
The kink around 2025 is due to our assumptions of a switch to celluosic ethanol, reducing biofuels use of food.
