Climate change and food production: Pakistan

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Climate change and food production Pakistan

• M. Arif Goheer
• Global Change Impact Studies Centre (GCISC)
• Islamabad Pakistan
• GECAFS IGP CPWF and APN Launch Workshops
• Kathmandu-Nepal, June 27-30, 2006

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• Climate Change
• the greatest challenge facing the world at the
  beginning of the century
• World Economic Forum Davos, Switzerland
  2000

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Changing Climatic Trends

• Increasing concentration of CO2 in the atmosphere
• Pre-industrial revolution (1789) 280 ppm
• Present (2004) 380 ppm
• Expected level (2050) 550 ppm
• Rising surface temperatures
• Global Av. Temp. rise (20th century) 0.6 C
• Projections for 2100 1.4 to 5.8 C
• Changing rainfall patterns

Source IPCC, 2001
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Depending on the level of GHG emissions and
concentration in the atmosphere, the average
global temperature would rise between 1.4 oC
5.8 oC over the 21st Century
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Climate and Food Production

• Weather and Climate are the key factors in food
  productivity
• Being open to vagaries of nature, food
  production are highly vulnerable
• to climate change phenomena

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Climate Related Parameters of Agricultural
Productivity

• CO2
• Temperature
• Solar Radiation
• Precipitation
• Others (Wind speed and direction, Soil Moisture,
  Water vapour, etc.)
• Basic understanding of these factors helps
  manipulate plants to meet human needs of food,
  fiber and shelter
• The parameters also help understand impacts of
  climate change and devise adaptation/mitigation
  strategies

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Climate-Water-Food Linkages
GDD and Corresponding GSL
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Projections of IPCC for South Asia

• Increase in surface temperature will contribute
  to snowmelt resulting in risk of floods
• Indus river inflows will decrease by 27 by the
  year 2050
• Land degradation will cause land to shrink from
  present 0.8 ha per capita to 0.3 by 2010
• Areas in mid and high latitudes will experience
  increase in crop yield whereas in lower latitudes
  will experience a general decrease, under
  elevated CO2 conditions

IPCC, 2001
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Semi-arid areas

• Crop models showed that increase in temperature
  of 0.9 and 1.8C resulted in reduction in length
  of wheat growing season by 4 and 8 days
  respectively
• At 0.9C increase in temperature, wheat grain
  yield increased by 2.5 whereas at 1.8C
  increase, the grain yield decreased by 4
• The increase in temp. would reduce the
  productivity of rice crop due to heat stress and
  reduction in growing season length

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Arid areas

• Crop modeling studies showed a non significant
  trend in wheat yields under increased
  temperature scenarios (0.9C and 1.8C)
• Wheat straw yields were reduced by 7 and 12
  with temperature increases of 0.9C by 2020 and
  1.8C by 2050

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Impacts on Food Production

• Due to Increasing Temperatures
• Shift in spatial crop boundaries will have
  enormous economic and social impact.
• e.g. Rice transplantation, Cotton picking etc.
• Increase/decrease in crop yields
• Rise in evapotranspiration rates, calling for
  greater efficiency of water use
• Shift in timing of developmental stages of pests
  in Crop-weed-pest relationships

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Due to Change in Precipitation Pattern

• More dependency on ground water in the face of
  low precipitation
• danger of depletion of aquifer due to
  injudicious pumping
• increased cost of cultivation
• soil salinization due to poor quality ground
  water

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Effect of water supplies

• Decreased Surface Water Supplies
• Reduction in yield and quality of crops due to
  water stress during critical growth stages
• Shift in cropping patterns
• Nitrogen volatilization losses from ammonical
  fertilizers

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• b) Increased Water Supplies
• Potential development of Water logging and
  Salinity/Sodicity
• Denitrification losses from ammonical and
  nitrate based fertilizers
• Shift in cropping patterns
• Increased incidence of plant diseases

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• Extreme Weather Events
• In addition to changing climate, increased
  variability in weather may occur with consequent
  frequent extreme events such as heat waves,
  droughts, wind storms and floods having negative
  impacts on agriculture

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Pakistans Resource Base

• LAND (in million hectare)
• Geographical area 79.6
• Area under cultivation 27.6 (21.87)
• Crop area irrigated 22.6 (17.99)
• Rainfed Agriculture area 4.97 (21.87)
• Forest 4.5 (3.61)
• Culturable waste 11.7 (9.31)
• Range Lands 59 (46.96)

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Cropping Seasons

• Rabi
• November-April
• Wheat, Lentil, Chickpea
• Kharif
• May-October
• Rice, Maize, Mungbean, Cotton

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Agricultural productivity
Agricultural Statistics of Pakistan 2001-02
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Demand and Production projections with respect to
climate change in Pakistan
Million Bales
Source CICERO 20002
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• Work Done at GCISC

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• Wheat Rice Simulation Results
• using DSSAT based CERES-Wheat CERES-Rice models
• Semi-arid areas
• Arid areas
• Humid area
• Sub-humid areas

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Effect of Increase in Temperature and CO2levels
on Wheat yields
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Effect of Increase in Temperature CO2levels and
Water Scenarios on Wheat yields
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Effect of Increase in Temperature CO2levels and
Water Scenarios on Wheat yields
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Effect of Increase in Temperature on Wheat GSL
(DSSAT based results 1994-95 to 2003-04 for Cv.
Inqalab sown on Nov. 20th)
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Effect of Increase in Temperature and CO2levels
on Rice yields in Semi-arid areas of Punjab
Baseline Yield
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Effect of increase in Temperature on GSL of Rice
in Semi arid areas of Punjab (Faisalabad)(Cv.
Basmati Super transplanted in 1st Week of July)
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Conclusions

• Rise in CO2 level only has positive impact on
  wheat yield
• Rise in Temperature shows negative impact on
  wheat yield
• But it could be mitigated if CO2 level 550 ppm
• Negative impact of Rise in Temperature on yield
  could also be mitigated by increasing number of
  Irrigations (but)
• Reduction in water resources shows a negative
  impact on wheat yield
• Even 550 ppm CO2 level would not result in
  sustaining current yield level if water resources
  reduce
• Rise in CO2 levels could sustain the baseline
  Rice yields up to 1C

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