Global Environmental Change Impacts on the Caribbean Food System Ulric O’D Trotz, Ph.D Project Manager ACCC Project

Working Group I of the IPCC TAR Concluded Global average surface temperature increased by 0.6±0.2°C over 20 th Century For range of scenarios considered global average surface temp. projected to warm °C by 2100 relative to 1990 Global average sea level projected to rise m by 2100 Changes in climatic variability, and frequency and intensity of some extreme climate events

Observational evidence indicates that regional changes in climate ( esp. inc. temp.) have already affected many physical and biological systems Shrinkage of glaciers Thawing of permafrost Later freezing and earlier breakup of ice on rivers and lakes Lengthening of mid to high latitude growing seasons Poleward and altitudinal shifts of plant and animal ranges Declines of some plant and animal populations Earlier flowering of trees, emergence of insects and, egg laying in birds

Systems Sensitive to Climate Change Water resources Agriculture (esp. food security) Forestry Coastal zones and marine systems (fisheries) Human settlements, energy and industry Insurance and other financial services Human health

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

Projected Beneficial Impacts Increased potential crop yields in some regions at mid-latitudes for increase in temperature Potential increase in global timber supply for appropriately managed forests Increased water availability for populations in some water scarce regions

Agriculture and Food Security Crop yield responses to climate change varies, and depends on: –Species and cultivar –Soil properties –Pests and pathogens –Interactions between C0 2, air temperature, water stress, mineral nutrition, air quality and adaptive responses

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 temperature regions – detrimental to numerous crops

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

Temperature Mean annual temperature increase of 2.5°C 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.

Temperature Increases in extreme events likely to increase heat stress-related livestock deaths Winter warming may reduce neonatal deaths at temperate latitudes

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

Research on direct effects of CO 2 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

Confidence in outputs low due to uncertainties in: –Magnitude and persistence of rising CO 2 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

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

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

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

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.

Some Regional Projections Africa –Vulnerability high as a result of heavy dependence on rain-fed agriculture, frequent droughts and floods –Grain yields projected to decrease diminishing food security, particularly in small food-importing countries –Increased droughts, floods and other extreme events add stress to food security –Significant extinctions of plant and animal species projected and would impact rural livelihoods

Asia –Decreases in agricultural productivity and aquaculture –Diminished food security in many countries of arid, tropical and temperate Asia –Expanded agriculture and increased productivity in Northern areas

Australia / New Zealand –Net impact on some temperate crops of climate and CO 2 changes may initially be beneficial, but balance is expected to become negative for some areas and crops with further climate change. –Water stress in some regions due to change to a more El Niño-like average state

Europe –Broadly positive effects on agriculture in Northern Europe; decrease in productivity in Southern and Eastern Europe –Negative impacts on average due to increased river flood hazard, erosion and wetland loss

Latin America –Yields of important crops projected to decrease even when effects of CO 2 taken into account –High threat to subsistence farming

North America –Some crops would benefit from modest warming accompanied by increased O 2 but effects would vary among crops and regions –Declines due to drought in some areas of Canadian Prairies and US. Great Plains –Potential increased food production in areas of Canada, North of current production areas –Benefits for crops would decline at an increasing rate and become net loss with further warming