Climate Change and Agriculture Cynthia Rosenzweig NASA/Goddard Institute for Space Studies Congressional Briefing on Climate Change and Agriculture: Food and Farming in a Changing Climate June 16, 2010
Climate Change and Agriculture
Cynthia Rosenzweig
NASA/Goddard Institute for Space Studies
Congressional Briefing on
Climate Change and Agriculture: Food and Farming in a Changing Climate
June 16, 2010
Agriculture Contributes to Climate Change
Observed increase in methane is
due to anthropogenic activities,
predominantly rice production and
ruminants.
More than a third of all nitrous oxide
emissions are agricultural, primarily
due to fertilizer.
Primary source of increased carbon
dioxide is fossil fuel use, with land-
use change providing a significant
contribution.
Observed warming is just a small fraction of what is projected
IPCC 2007
The 100 year
linear trend
(1906-2005) in
temperature is
0.74 oC
0.6 oC
1.8 oC
2.8 oC
3.4 oC
Continued Greenhouse Gas Emissions Would Cause Further Warming
6.0 oC
Figure SPM-6
Updated:
PLENARY
Warming is Expected to be Greatest over Land and at Most High Northern Latitudes.
Figure SPM-6
Updated:
PLENARY
Warming is Expected to be Greatest over Land and at Most High Northern Latitudes. Hot Extremes and Heat Waves will Continue to Become More Frequent
Figure SPM-7
Updated:
PLENARY
Increases in Precipitation are Very Likely in the High-Latitudes, while Decreases are Likely in Most Subtropical
Land Regions
2090s
Figure SPM-7
Updated:
PLENARY
Increases in Precipitation are Very Likely in the High-Latitudes, while Decreases are Likely in Most Subtropical
Land Regions
Heavy Precipitation Events will Continue to Become More Frequent
2090s
Increasing
Droughts
and Floods
0
20
40
60
80
100
1990 2000 2010 2020 2040 2040 2050
Year
Pe
rce
nta
ge
R eliab ility
D em and m et
400
300
200
100
50O N D
Months
J F M A M J J A S
Runoff
(cfs
) CurrentGFDLMPIHC
Changes in
Seasonality
Water Resources are Key
Strzepek et al., 1999
Competing Demands
Domestic Users
Ecosystem Services
Excess Soil Moisture
Number of events causing damage to maize yields due to excess soil moisture
conditions, averaged over all study sites, under current baseline (1951–1998) and
climate change conditions. Events causing a 20% simulated yield damage are
comparable to the 1993 US Midwest floods (Rosenzweig 2001).
YieldsOver the last 50 years:
• Very likely
– less frequent cold days, cold
nights, and frosts
– more frequent hot days and hot
nights
• Likely
– more frequent heat waves
– more frequent heavy
precipitation events
– increased incidence of extreme
high sea level
– increased drought in some
regions
Climate Change is Already OccurringObserved impacts on Agriculture
Phenology
Management
practices,
pests and
diseases
Livestock
1973-2002 Annual temperature trends
<-1.2C to >1.2C
IPCC, 2007
Phenology
Management
practices,
pests and
diseases
Yields
Livestock
Rosenzweig et al.,
IPCC WGII Chapter 1, 2007
Climate Change is Already Affecting Agriculture
Seasonal-to-interannual – e.g., El Nino*
Decadal-to-century**
Feb1998
Feb 2000
ENSO Uruguay
Baethgen, 2000
Risk of Current Climate Extremes is
a Pathway to Climate Change
NOAA AVHRR
*Focus on Extreme events
Regional StakeholdersShort-term Decisions
Adaptation
**Focus on Mean changes
National PolicymakersGlobal Agreements,
Adaptation & Mitigation,World Food System
Ing. Juan Notaro, Uruguayan Minister of Agriculture in 1999/2000
"... The results of your work during the recent drought were useful for making
both operational and political decisions.”
The Agricultural Modeling Intercomparison and
Improvement Project (AgMIP)
• Provides global context to regional climate change
impacts on agricultural systems
• Assesses uncertainties and adaptation strategies
Climate Scenarios
Crop Models
Food Trade Models
Historical Observations,
CMIP5 and Earth
System Models
Major Crop Modeling
Groups, Regional
Agricultural Experts
Major Economic
Modeling Groups
Online Project
Guidance, Archive,
and Clearinghouse
Intercomparisons
Crop Models
Food Trade Models
Gauge Uncertainties
Adaptation Capacity Building
Adaptation and Mitigation
Regional Crop Assessments
Trade Policy Instruments
Technological Exchange
Extended Applications
Water Resources
Pests and Diseases
Livestock and Pastures
Vulnerability