Global Environmental Change Impacts on the Caribbean Food System

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Global Environmental Change Impacts on the
Caribbean Food System

• Ulric OD Trotz, Ph.D
• Project Manager
• RPIU/ACCC Project

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Working Group I of the IPCC TAR Concluded

• Global average surface temperature increased by
  0.60.2C over 20th Century
• For range of scenarios considered global average
  surface temp. projected to warm 1.4-5.8 C by
  2100 relative to 1990
• Global average sea level projected to rise
  0.09-0.88m by 2100
• Changes in climatic variability, and frequency
  and intensity of some extreme climate events

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Projected Adverse Impacts

• General reduction in crop yields in most tropical
  and subtropical regions for most projected
  increase in temperature
• General reduction, with some variation, in
  potential crop yields in most regions in
  mid-latitudes for increase in annual average
  temperature
• Reduced water availability in most water scarce
  regions
• Widespread increase in risk of flooding from
  increased heavy precipitation events and sea
  level rise
• populations in some water scarce regions

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Agriculture and Food Security

• Crop yield responses to climate change varies,
  and depends on
• Species and cultivar
• Soil properties
• Pests and pathogens
• Interactions between C02, air temperature, water
  stress, mineral nutrition, air quality and
  adaptive responses

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Temperature

• In tropics, some crops near their max.
  temperature tolerance yields expected to decrease
  with even minimal changes in temperature. If
  coupled with large reductions in rainfall, crop
  precipitation yields even more adversely
  affected.
• Few degrees projected warming will lead to
  general increase in temperate crop yields. larger
  amounts of warming will lead to a reduction.
• Higher minimal temperatures beneficial to some
  crops, especially in temperate regions
  detrimental to numerous crops

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Temperature

• In the absence of climate change most studies
  predict declining real prices for agricultural
  commodities
• Impacts of climate change on agriculture
  estimated to result in small percentage changes
  in global income positive in developed regions,
  and smaller or negative in developing world

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Temperature

• Mean annual temperature increase of 2.5C or
  greater, prompt food prices to increase as a
  result of slowing expansion of global food
  capacity relative to growth in global food
  demand.
• At lesser amounts of warming, global impact
  assessment models cannot distinguish climate
  signal from other sources of change
• Recent aggregated studies estimated economic
  impacts on small holder producers and poor urban
  consumers, indicate that climate change will
  lower incomes of vulnerable populations and
  increase number of people at risk to hunger.

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• Subsistence agricultural production vital to the
  economies, nutritional status and social
  well-being of SIDS
• Climate change could precipitate heat stress,
  changes in soil moisture and temperature,
  evapotranspiration, rainfall
• Such changes may affect growth of some
  subsistence root crops and vegetables.
  Consequences likely to be more severe in areas
  already under stress, for example, water scarce
  islands. Agriculture can also be affected by
  tropical cyclones and other extreme events such
  as floods and droughts.
• Likely that crop production will be impacted by
  alterations in patterns of these events, as a
  consequence of climate change

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Degradation of Soil and Water Resources one of
the major challenges for global agriculture

• Established that these processes likely to be
  intensified by adverse change in temperature and
  precipitation
• Land use and management has greater impact on
  soil conditions than indirect effect of climate
  change
• Opportunity to mitigate the latter

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Carbon dioxide

• Research on direct effects of CO2 on crops
  suggest that beneficial effects may be greater
  under certain stressful conditions including
  warmer temperature and drought
• Effects established for a few crops under
  experimental conditions yet to be validated in
  on-farm conditions
• Numerical estimates of climate change impacts on
  production, income, prices obtained from
  aggregated integrated assessment models

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Carbon Dioxide

• Confidence in outputs low due to uncertainties
  in
• Magnitude and persistence of rising CO2 on crop
  yield under realistic farming conditions
• Potential changes in crop and animal pest losses
• Spatial variability in crop responses to climate
  change
• Effects of changes in climate variability and
  extreme events on crops and livestock

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Carbon Dioxide

• GCM (CCCII) outputs and high, medium and low CO2
  emission scenarios coupled with FAO crop model to
  simulate crop yields
• Sugar cane yields may ltlt from between 20-40
  under 2 x CO2 climate change scenario in Trinidad
  and Tobago
• Attributed to gtgtmoisture stress caused by warmer
  climate. Results supported by findings in
  Mauritius
• Derived from Agricultural Production Systems
  Simulator Model (APSIM Sugarcane)
• Projects decline in sucrose yield by more than
  50 for doubling CO2
• Work on maize (C4 crop) in Venezuela also
  predicts declining yields

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Sea Level Rise, Sea Surface Temperature

• Salt water intrusion into estuaries
• Salinization of aquifers and agricultural soil
• Inundation
• Impacts on marine ecosystems reefs (sea water
  temp), sea grass beds, mangroves

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Fisheries

• Habitat degradation mangroves, reefs, sea grass
  beds
• Profound impact on biological production of
  oceans including fish production changes in
  upwelling rates would have major impact on
  coastal fish production
• Increase in frequency of El Niño events will lead
  to decline of plankton biomass and fish larvae
  abundance adverse effect on fish and ocean
  biodiversity

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Fisheries

• Fluctuations in fish abundance are increasingly
  regarded as
• Biological responses to medium term climate
  fluctuations in addition to
• Overfishing
• Other anthropogenic factors

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Fisheries

• Growing recognition of the role of the
  climate-ocean system in management of fish stocks
  leading to new adaptive strategies based on
  determination of acceptable removable percentages
  of fish stock resilience.
• Adaptation by expansion of marine aquaculture
  in 1997 accounted for about 30 total commercial
  fish and shell production.
• Conservation, restoration and enhancement of
  vital habitats
• Establishment of marine reserves and protected
  areas for identified critical species