climate change: impacts on crop production and the environment
TRANSCRIPT
Climate Change: Impacts on Crop Production and the Environment
Bano MehdiDepartment of Geography
McGill University
McGill Conference on Global Food SecurityOctober 5-7, 2009, McGill University
Session on : Climate Change and Food Security
IntroductionClimate will become more variable, and will changeParticularly the climate parameters of
TemperaturePrecipitation
How will this affect agricultural crop production?What are the ramifications on the environment?
What does this mean for land use change?What are the consequences for water quality?
Introduction Temperature Precipitation Environment Conclusion
Temperature predictions:Multi model averages and assessed ranges for surface warming
IPCC 2007: WG1-AR4
Best estimate
Introduction Temperature Precipitation Environment Conclusion
Temperature change and crop production1. Longer growing season length2. Increases in crop damage & yield reductions3. Adjusting production patterns4. Interactions among crops, weeds, insects, and disease
Introduction Temperature Precipitation Environment Conclusion
Global impacts of climate change on agriculture
IPCC 2007: WG2-AR4
Mid to high-latitude crops benefit from a small warming (~+2oC) but plant health
declines with additional warming
Longer growing season: land use changeOpportunities may arise for farmersNorthward extension of crop lands and grazing zones Drivers for change
Longer growing seasonHigher GDDSubsidies (biofuels)Land more valuableAccess to marketsAccess to knowledge
???
Introduction Temperature Precipitation Environment Conclusion
Precipitation predictions:Projected patterns of global precipitation changes (scenario A1B)
IPCC 2007: WG1-AR4
Winter Summer
Introduction Temperature Precipitation Environment Conclusion
Impacts of precipitation changesVariable precipitation patterns
Less reliableFrequency of extreme eventsIntensity increases
Impacts on soil erosion
SWCS 2003
Introduction Temperature Precipitation Environment Conclusion
Erosion rates•15 and 30 min rainfall intensities have increased by 10%. Greatest for the 2 and 5 yr return periods.•For a 10% increase in mean annual ppt, change in erosion by 24% and change in runoff by 25%.
Water quality implicationsIntense events will contribute to higher erosionSurface runoff likely to increaseLand use will affect the severity of water quality degradation
???IWRM and BMPs are tools to help relive the burden of ag areas contributing to pollution, and can assist with water management plans
(A. Jamieson)
(C. Pertchy)
Introduction Temperature Precipitation Environment Conclusion
Other global change impacts on crop production
Population changeDemands
Energy changesBiofuel crops
Economic changeMarket factors
…
Introduction Temperature Precipitation Environment Conclusion
EC 2008
In Closing:Climate change impacts on crop production
Temperature increasesLonger growing seasonFrost incidences
Precipitation variationsMore intense events
Elevated CO2
Resulting non-climatic factors impacting the environmentWaterNutrientsErosion Pests …
Introduction Temperature Precipitation Environment Conclusion
Thank you