Climate Change and Agriculture

Transcription

1 Climate Change and Agriculture Congressional Briefing on Climate Change and Agriculture: Food and Farming in a Changing Climate June 16, 2010 Cynthia Rosenzweig NASA/Goddard Institute for Space Studies

2 Agriculture Contributes to Climate Change Primary source of increased carbon dioxide is fossil fuel use, with landuse change providing a significant contribution. 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.

3 Observed warming is just a small fraction of what is projected Continued Greenhouse Gas Emissions Would Cause Further Warming 3.4 o C 6.0 o C 2.8 o C 1.8 o C 0.6 o C The 100 year linear trend ( ) in temperature is 0.74 o C IPCC 2007

4 Warming is Expected to be Greatest over Land and at Most High Northern Latitudes. Updated: PLENARY Figure SPM-6

5 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 Updated: PLENARY Figure SPM-6

6 2090s Increases in Precipitation are Very Likely in the High- Latitudes, while Decreases are Likely in Most Subtropical Land Regions Updated: PLENARY Figure SPM-7

7 2090s 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 Updated: PLENARY Figure SPM-7

8 Runoff (cfs) Water Resources are Key 100 P ercentage D em and m et R eliab ility Increasing Droughts and Floods Year Changes in Seasonality Current GFDL MPI HC Competing Demands Domestic Users Ecosystem Services O N D J F M A M J J A S Months Strzepek et al., 1999

9 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 ( ) and climate change conditions. Events causing a 20% simulated yield damage are comparable to the 1993 US Midwest floods (Rosenzweig 2001).

10 Climate Change is Already Occurring Observed impacts on Agriculture Yields Phenology Over the last 50 years: Very likely less frequent cold days, cold nights, and frosts more frequent hot days and hot nights Management practices, pests and diseases Annual temperature trends <-1.2C to >1.2C Livestock Likely more frequent heat waves more frequent heavy precipitation events increased incidence of extreme high sea level increased drought in some regions IPCC, 2007

11 Phenology Climate Change is Already Affecting Agriculture Yields Management practices, pests and diseases Livestock Rosenzweig et al., IPCC WGII Chapter 1, 2007

12 ENSO Uruguay Risk of Current Climate Extremes is a Pathway to Climate Change Feb1998 Seasonal-to-interannual e.g., El Nino* Decadal-to-century** NOAA AVHRR Baethgen, 2000 Feb 2000 *Focus on Extreme events Regional Stakeholders Short-term Decisions Adaptation Ing. Juan Notaro, Uruguayan Minister of Agriculture in 1999/2000 **Focus on Mean changes National Policymakers Global Agreements, Adaptation & Mitigation, World Food System "... The results of your work during the recent drought were useful for making both operational and political decisions.

13 The Agricultural Modeling Intercomparison and Improvement Project (AgMIP) Historical Observations, CMIP5 and Earth System Models Climate Scenarios Major Crop Modeling Groups, Regional Agricultural Experts Major Economic Modeling Groups Crop Models Food Trade Models 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 Provides global context to regional climate change impacts on agricultural systems Assesses uncertainties and adaptation strategies