The Latest Scientific Assessment of Climate Change and its Impacts on World Food Security—the IPCC...
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Transcript of The Latest Scientific Assessment of Climate Change and its Impacts on World Food Security—the IPCC...
The Latest Scientific The Latest Scientific Assessment of Climate Assessment of Climate Change and its Impacts Change and its Impacts on World Food Securityon World Food Security
—the IPCC Reports—the IPCC Reports
William E. EasterlingWilliam E. Easterling
Penn State UniversityPenn State University
The FactsThe Facts
Fact 1: The Fact 1: The Greenhouse Effect is Greenhouse Effect is
realreal
Without the Greenhouse Effect, the Earth’s surface temperature averages ~30˚C colder
NATURAL GREENHOUSE EFFECT
Fact 2—the chemistry of the global atmosphere is changing
ENHANCED GREENHOUSE EFFECT
What is the oscillation
due to?
Historical CO2 measurements
Began in 1958
Prehistoric Greenhouse Gas Measurements
Recent rise of atmospheric greenhouse gas Recent rise of atmospheric greenhouse gas concentrations is unprecedented in last 10,000 yrs—ice concentrations is unprecedented in last 10,000 yrs—ice
cores suggest even the last 650,000 yrscores suggest even the last 650,000 yrs
IPCC-SPM, 2007
Fact 3—human activity is Fact 3—human activity is the source of the rise in the source of the rise in greenhouse gas greenhouse gas concentrationsconcentrations
Fact 4—Fact 4—Ipso factoIpso facto from the from the previous two facts: radiative previous two facts: radiative forcing of the atmosphere is forcing of the atmosphere is
increasingincreasing
Growth in fossil fuel emissions highly Growth in fossil fuel emissions highly correlated with growth in atmospheric correlated with growth in atmospheric
COCO22
Total radiative forcing—a measure of the stengthening of the greenhouse effect—has increased by 20% (~+1.5Wm-
2) over the past decade.
Several lines of Several lines of evidence have evidence have
converged giving high converged giving high confidence that the confidence that the Earth’s climate is Earth’s climate is changing………changing………
UK going Mediterranean in 2003Katrina fueled bywarm Gulf water
Research has narrowed Research has narrowed the attribution of the attribution of
observed warming to observed warming to human activity…….human activity…….
General Circulation Models (GCMs) take into account the full three-dimensional
structure of the atmosphere and ocean
Black line is observed temperature
Orange is simulated temperature
Blue is simulated temperature
Rate and amount of warming is dependent on the Rate and amount of warming is dependent on the political, social and economic factors that govern political, social and economic factors that govern
emissionsemissions
Range of warming is ~1-4˚C by 2100
Sustainability World
Early Demographic Transition World
Late Demographic Transition World
Warming to 2030 (~0.8˚C)
warming to 2100 (~2-2.2˚C)
White areas are where less than 2/3 of White areas are where less than 2/3 of models agree; stippled areas are where models agree; stippled areas are where more than 9/10 of models agreemore than 9/10 of models agree
++
--
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Effects on Global Effects on Global Food SecurityFood Security
Green = with adaptation
Red = without adaptation
= reference line for current yields
Cereal Yield Response to Warming—Temperate vs. Tropical Regions
(with and without simulated adaptation)
Temperate yields tend to thrive until +3˚C Tropical yields tend to
decline immediately
Simple adaptations extend temperate crops to +4-5 ˚C but tropical yields only to +2-3˚C
One of the earliest One of the earliest effects of climate effects of climate change is likely to be change is likely to be the range of crop pests the range of crop pests and diseasesand diseases
Simulated spread of Simulated spread of soybean rust into the U.S. soybean rust into the U.S. with Hurricane Ivan was with Hurricane Ivan was scary accurate!scary accurate!
Pan and Yang, 2004 Science
What happens when What happens when conventional adaptive conventional adaptive measures are measures are exhausted?—will exhausted?—will biotechnology be the biotechnology be the answer?answer?
Global Area of Transgenic Crops: Global Area of Transgenic Crops: Industrial and Developing Industrial and Developing Countries (1996- 2000)Countries (1996- 2000)
0
5
10
15
20
25
30
35
40
1995 1996 1997 1998 1999 2000
Mil
lion
hec
tare
s
IndustrialcountriesDevelopingcountries
Biofuels as Adaptation Biofuels as Adaptation and Mitigation: Does and Mitigation: Does energy have to energy have to compete with food?compete with food?
Availability of Currently Availability of Currently Unused Arable Land for Unused Arable Land for Food and/or Bioenergy Food and/or Bioenergy Crops (est. by FAO)Crops (est. by FAO)
SummarySummary Greenhouse effect is getting strongerGreenhouse effect is getting stronger
Multiple lines of evidence of warming are consistent Multiple lines of evidence of warming are consistent and more certain than everand more certain than ever
Models are making the case that most of the Models are making the case that most of the warming is attributable to GHG emissionswarming is attributable to GHG emissions
Warming by end of century could be equal to 60-Warming by end of century could be equal to 60-80% of the warming since the last ice age until now80% of the warming since the last ice age until now
Global food production likely to be adequate overall Global food production likely to be adequate overall but unequal distribution harming food security in but unequal distribution harming food security in the tropicsthe tropics