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Terrestrial Ecosystem Response to Climate Change. Global Change and Effects on Terrestrial Ecosystem. Introduction Temperature, precipitation, latitude and altitude all determine distribution of major terrestrial ecosystems (biomes).

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Global change and effects on terrestrial ecosystem l.jpg
Global Change and Effects on Terrestrial Ecosystem

Introduction

  • Temperature, precipitation, latitude and altitude all determine distribution of major terrestrial ecosystems (biomes).

  • Plants found within the different biomes are influenced by soil type, water shed conditions and amount of sun.

  • Specific combinations of temperatures and precipitation ensure the survival and thriving of plants within a given environment (known as Climate space).


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Terrestrial Ecosystems are an…

  • Integral part of global carbon system

  • Plants take in and store carbon dioxide from the atmosphere through photosynthesis

  • Below ground microbes decompose organic matter and release organic carbon back into the atmosphere

www.bom.gov.au/.../ change/gallery/9.shtml

Cycle shows how nature’s sources of CO2 are self regulating – that which is released will be used again – Anthropogenic carbon not part of natures cycle – is in excess


Major biomes and their vegetation l.jpg
Major Biomes and Their Vegetation

  • Tundra – no trees, lichens, grasses and shrubs

  • Taiga (or Boreal Forest) – coniferous evergreens

  • Temperate forests – include evergreens (spruce), deciduous forests (oaks), mixed forests, and temperate rain forests (sequoias)

  • Tropical rain forests – greatest amount of diversity in vegetation (vines, orchids, palms)

  • Grasslands – grasses, prairie clover

  • Deserts – cacti, small bushes


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Major Terrestrial Biomes

  • Geographic distribution of biomes are dependent on temperature, precipitation, altitude and latitude

  • Weather patterns dictate the type of plants that will dominate an ecosystem

faculty.southwest.tn.edu/. ../ES%20%20we16.jpg


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Million years before present

570 505 438 408 360 286 245 208 144 66 2 10K


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Global Distribution of Vegetation 18,000 years ago

tundra

grassland

taiga

conifers

woodland

desert

Prentice, C.I., Guiot, J., Huntley, B., Jolly D. and Cheddadi, R., 1996, Reconstructing biomes from palaeoecological data: a general method and its application to European pollen data at 0 and 6 ka. Climate Dynamics 12:185-194.


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Global Distribution of Vegetation 6,000 years ago

temperate deciduous

cold deciduous

taiga

tundra

conifers

desert

grassland

woods & scrub

Prentice, C.I., Guiot, J., Huntley, B., Jolly D. and Cheddadi, R., 1996, Reconstructing biomes from palaeoecological data: a general method and its application to European pollen data at 0 and 6 ka. Climate Dynamics 12:185-194.


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Global Distribution of Vegetation - Present

tundra

taiga

temperate deciduous

cold deciduous

warm mix

grassland

tropical R.F.

Prentice, C.I., Guiot, J., Huntley, B., Jolly D. and Cheddadi, R., 1996, Reconstructing biomes from palaeoecological data: a general method and its application to European pollen data at 0 and 6 ka. Climate Dynamics 12:185-194.


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Shifts in Terrestrial Habitat

18Kya

18 kya

ice

ice sheet

oak

spruce

  • 18,000 years ago Spruce trees and oak trees filled small pockets of habitat – as climates warmed Spruce trees migrated into the Northern Hemispheres and the Oak trees expanded in to Southeastern U.S., Western Europe and Southern Europe

  • Shifts in vegetation occur slowly tree species were able to successfully expand into favorable regions

spruce

9Kya

9 kya

ice

ice

spruce

oak

Present

Present

spruce

ice

spruce

oak

oak

Distribution of spruce and oak forests in Northern Hemisphere since the Last glacial period 18,000 kya


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tundra

PRESENT

DAY

BIOMES

taiga

taiga

desert

temp.

decd. forest

desert

grassland

trop. rain forest

scrub forest

desert

temp rain forest


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Tundra

Greenland

Alaska

N. Europe

Siberia

Yakutsk

Canada

Ice land


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Average annual temperature

and precipitation

Yakutsk, Russia

Location: 

62.1 N; 129 W

earthobservatory.nasa.gov


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Boreal Forest (Taiga)

Europe

Asia

Canada

S.W. U.S


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Boreal Forest (Taiga)

Average annual temperature

and precipitation

Beaverlodge, Alberta, Canada

55oN; 119o W

earthobservatory.nasa.gov


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Temperate Forests

Four types:

1. deciduous forests

2. evergreen forests

3. mixed deciduous and evergreen

4. temperate rain forests

Location: 

Eastern United States, Canada,

Europe, China, and Japan

www.windows.ucar.edu/.../ earth/forest_eco.html


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Average annual temperature and rainfall

Staunton, Virginia, United States

38oN; 79oW

earthobservatory.nasa.gov



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Tropical Rainforest

India

S.E. Asia

New Guinea

Zaire

Amazon river basin

Queensland

Madagascar

3 major geographical areas:

1. America: Amazon river basin

2. Africa: Zaire basin, small area of W. Africa, Eastern portion of Madagascar

3. Asia: West coast of India, Assam, S.E. Asia, New Guinea and Queensland, Australia

"Rainforests", http://passporttoknowledge.com/rainforest/GEOsystem/Maps/se_asia.html, (3/18/02)


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Campa Pita, Belize15 N latitude

Tropical Forest

Average annual temperature and precipitation

earthobservatory.nasa.gov


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Southeast Asia Tropical Rainforest Monsoons role

  • SE Asia has a tropical wet climate which is influenced by ocean wind systems originating in the Indian Ocean and China Sea

  • 2 monsoon seasons:

    • Northeast monsoons (Oct. – Feb) – bring heavy rains to Eastern side of the islands

    • Southwest monsoons (April – Aug) – more powerful of the two seasons – brings heavy rainfall to the western side of the islands – Eastern side of islands dry – but windy (due to rain shadow)

  • Change in monsoon cycle bring heavy consequences

    • Ex. 1992 – 1993 – logging degraded primary foresting making it vulnerable to fires. A drought brought on by El Nino created devastating fires destroying 27,000 km2 of acreage.

    • In 1998 the same type of thing happened again when El Nino created a weak monsoon season – destroying many plant and animal species.



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    Average annual temperature and rainfall

    Ingeniera White, Argentina

    40oS; 6oW

    earthobservatory.nasa.gov



    Slide25 l.jpg

    Average yearly temperature and rainfall

    El-Oasr el-Akhdar, Egypt26oS; 30oE

    earthobservatory.nasa.gov


    So what are the predictions l.jpg

    woodland

    shrub land

    grassland

    forest

    arid

    Present day

    grassland

    forest

    grassland

    grassland

    shrub land

    woodland

    Predicted Distribution

    So … what are the predictions?????

    • Arid deserts in Southwestern U.S. will shrink as precipitation increases

    • Savanna/shrub/woodland systems will replace grasslands in the Great Plains

    • Eastern U.S. – forests will expand northerly – weather conditions will become more severe

    • Southeastern U.S. – increasing droughts will bring more fires – triggering a rapid change from broadleaf forests to Savannas

    Climate change p. 104


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    Predicted Change in Biomes

    Loss of existing habitat that could occur under doubling of CO2 concentration. Shades of red indicate percentage of vegetation models that predicted a change in biome type.


    Slide28 l.jpg

    Distribution of Sugar Maple in Eastern North America will change due to an increase in temperature and a decrease in moisture shifting further north east.

    Predictions of Sugar Maple in Eastern NorthAmerica

    predicted new growth

    predicted new growth

    overlap

    overlap

    present range

    present range

    Prediction based on Prediction based on increased

    increased temperature temperature and decrease precipitation


    Slide29 l.jpg

    More Predictions will change due to an increase in temperature and a decrease in moisture shifting further north east.

    Western Hemlock and Douglas fir found on Western slope

    • Douglas Fir found in wet coastal mountains of CA and OR will shrink in low lands and be replaced by Western pine species which are more drought tolerant.

    • Overall Western U.S. climate is predicted to shift to favor more drought tolerant species of pine

    Wet western slope will shrink and be replaced by pine and oak

    Eastern slope will become drier and shift to Juniper and Sagebrush



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    Shifts in Terrestrial Habitat American boreal forest area.

    Potential distribution of the major world biomes under current climate conditions

    • It is predicted that at the end of this century there will be large scale shifts in the global distribution of vegetation in response to anthropogenic climate change.

    • With man doubling the amount of carbon dioxide entering into the atmosphere the climate is changing more rapidly then plant migration can keep up.

    Projected distribution of the major world biomes by simulating the effects of 2xCO2-equivalent concentrations

    www.usgcrp.gov/usgcrp/ seminars/960610SM.html


    Boreal and alpine vegetation l.jpg
    Boreal and Alpine Vegetation American boreal forest area.

    Predicted changes in Siberian vegetation in response to doubling of CO2

    • Research indicates the greatest amount of change will occur at the higher latitudes

    • Northern Canada and Alaska are already experiencing rapid warming and reduction of ice cover

    • Vegetation existing in these areas will be replaced with temperate forest species

    • Tundra, Taiga and Temperate forests will migrate pole ward

    • Some plants will face extinction because habitat will become too small (ex. Mountain tops of European Alps)

    Climate change


    Grasslands and shrub lands l.jpg
    Grasslands and Shrub Lands American boreal forest area.

    • Grassland will change to deserts or shrub lands

      • Exposing greater amounts of soil

      • Increasing soil temperature – poor nitrogen content – poor plant growth

      • Barren soil exposed to winds and transported into atmosphere as dust and trapping IR – leading to more warming

    • Models of:

      • Climate change

      • Plant growth

      • Soil – water

        Predict shifts in distribution of major North American prairie grasses over a 40 year period


    Impacts on lebanon l.jpg
    Impacts on Lebanon? American boreal forest area.

    • recent studies found that the Arab region experienced an uneven increase in surface air temperature ranging from 0.2 to 2.0ºC that occurred from 1970 to 2004


    Impact high l.jpg
    Impact high… American boreal forest area.

    climate change impact

    Semi-arid and arid regions are highly vulnerable to climate change

    If temperature gets higher

    If precipitation gets lower

     pressure on natural and physical systems would be intensified


    The arab region will l.jpg
    The Arab region will… American boreal forest area.

    climate change impact

    Face an increase of 2 to 5.5 C in surface temperature by 2100

    Face a decrease in precipitation from 0 to 20%

     shorter winters

     dryer and hotter summers

     higher rate of heat waves

     higher level of weather variability

     more frequent occurrence of extreme weather events


    Impact on freshwater sources l.jpg
    Impact on freshwater sources American boreal forest area.

    climate change impact


    Status of freshwater here l.jpg
    Status of freshwater here American boreal forest area.

    climate change impact

    Reminder: most of the Arab countries are located in arid and semi-arid regions; low and limited water resources + high evaporation

    Total water resources = total renewable ground water + internal surface water resources + external surface water resources


    First order impacts l.jpg
    First order impacts… American boreal forest area.

    climate change impact

    • Mediterranean hydrological systems

      • Wetter winters

      • Dryer and hotter summers

      • Increase in evaporation from water bodies…

      • Increase Evapotranspiration from crops

    • Egypt

      • Increase the potential irrigation demand by 6 to 16% by 2100


    Drought l.jpg
    Drought American boreal forest area.

    climate change impact


    Drought frequency l.jpg
    Drought frequency American boreal forest area.

    climate change impact

    • Increased during the last 20 to 40 years in Morocco, Tunisia, Algeria and Syria

      • Of the 22 drought years in the 20th century, 10 occurred in the last 20 years, and three were successive (1999, 2000, 2001) in Morocco

      • Recent droughts in Jordan and Syria worst ever recorded

    • Varying conditions of water shortage in Lebanon in the last 10 years


    But not just droughts l.jpg
    But not just droughts American boreal forest area.

    climate change impact


    Yemen recent floods october 2008 l.jpg
    Yemen: recent floods (October 2008) American boreal forest area.

    Dubbed the 'Manhatten of the desert', Shibam's 2,000-year-old mud-brick buildings are in danger of collapsing after recent floods

    climate change impact


    Observed changes in physical and ecological systems from ipcc 2001 l.jpg
    Observed Changes in Physical and Ecological Systems American boreal forest area.(from IPCC 2001)

    hydrology / sea ice animals plants study covers study based on

    glaciers large area remote sensing


    Those at risk l.jpg
    Those at Risk American boreal forest area.

    • Northern countries (Russia, Sweden, Finland) ½ of existing terrestrial habitats at risk

    • In Mexico, it’s predicted that 2.4% of species will lose 90% of their range and threatened with extinction by the year 2055

    • Population at greatest risk are the rare and isolated species with fragmented habitats or those surrounded by water, agriculture or human development

    • Polar bears facing extinction by prolonged ice melts in feeding areas along with decline in seal population


    Slide46 l.jpg

    • 35% of worlds existing terrestrial habitat predicted to be altered

    • Studies found that deforestation in different areas of the globe affects rainfall patterns over a considerable region

      • Deforestation in the Amazon region of South America (Amazonian) influences rainfall from Mexico to Texas and in the Gulf of Mexico

      • Deforesting lands in Central Africa affects precipitation in the upper and lower U.S. Midwest

    www.sciencedaily.com/.../ 09/050918132252.htm


    Key conclusions from ipcc l.jpg
    Key Conclusions from IPCC altered

    Recent Regional Climate Changes, particularly Temperature Increases, have Already Affected Many Physical and Biological Systems

    (high confidence, or >67% sure)

    Biotic change: 44 regional studies, 400 plants and animals, 20 to 50 years

    Physical change: 16 regional studies, 100 processes, 20-150 yrs

    • non-polar glacier retreat

    • reduction in Arctic sea ice extent and thickness in summer

    • earlier plant flowering and longer growing season in Europe

    • poleward and upward (elevation) migration of plants, insects and animals

    • earlier bird arrival and egg laying

    • increased incidence of coral bleaching

    • increased economic losses due to extreme weather events


    Phenology l.jpg
    Phenology altered

    • Phenology: the study of a plant or animal’s progression through its life cycle in relation to the seasons

    • Another main indicator of climatic fingerprint

      • In Britain, for example, flowering and leafing occur 6 to 8 days earlier for every degree C rise in temperature


    Phenological changes l.jpg
    Phenological Changes altered

    • Life-cycles of plants and animals have been affected by global change

    • Temperatures affecting plants growing season, flowering time and timing of pollination by insects have all been altered

    • Studies already showing

      • Mediterranean deciduous plants now leaf 16 days earlier and fall 13 days later than 50 years ago

      • Plants in temperate zones flowering time occurring earlier in the season

      • Growing season increased in Eurasia 18 days and 12 days in N. America over past two decades


    Slide50 l.jpg

    Phenological Changes altered

    Penuelas J and Filella I 2001. Response to a warming world. Science 294: 793 – 795


    Important to know the particular species requirements l.jpg
    Important to know the particular species’ requirements altered

    • Migratory black-tailed godwit

      • Shore bird

      • Winters between Britain and Iberia

      • Breeding in summer in Iceland

      • Breeding pairs – high partner fidelity

      • Male and females winter in different locations – but arrive in Iceland typically within 3 days of each other

      • ?: how this degree of synchrony is maintained when the environmental conditions at the different sexes’ wintering sites are dissimilar?

    • Pied flycatcher

      • Migration is timed to availability of food for its nestlings

      • However – in parts of the Netherlands the caterpillars is now at its food peak early in the season. There – the flycatcher population is in decline

      • Will it be able to adapt in time?


    Biological communities and species shift l.jpg
    Biological communities and species shift altered

    • Some species do not migrate – but will shift their geographical position or range in response to CC

    • Climate is but one factor of many that determine a species’ spatial distribution – species rarely move uniformly with each other in response to climate change

    • Plus

    • Different species migrate at different rates

    • Thus: takes time for ecological communities to stabilize after a period of CC

    • Species at the leading edge of shifts/migrations tend to migrate faster than those already established

    • Changes are asymmetrical: species invading faster from lower elevations or latitudes than resident species receding upslope or poleward

      • Result: increase in species richness of communities at leading edge of migration

      • Transitory biodiversity

      • Plus: many of today’s systems are either managed or bound by land managed by humans == effective barrier to species migration

      • Problem: old ecological communities disrupted + impeding species migration halted


    Arctic lakes l.jpg
    Arctic lakes altered

    • 1997 - 2004: decline of 1170 large lakes (> 40 ha); 11%

    • Total regional lake surface area decreased by 6% (93 000 ha); 125 lakes vanished;

    • Northerly lakes increasing in size – by 12% (13 3000 ha)

      • Increased precipitation in the north

      • Southerly declines in lake area have outpaced northerly gains in lakes

      • The more southerly permafrost soils  no longer permanently frozen  allow lakes to rain


    Mountain snow and ice l.jpg
    Mountain snow and ice altered

    • Note: mountain snowpacks affect quantity and timing of water in streams supplying ecosystems in surrounding lowlands

    • Nearly all mountains of sufficient height on Earth have snow caps

    • Those will be reduced in volume – especially at lower latitudes

      • Smaller mountain snow caps may be seasonally thicker due to extra precipitation

    • Already happening – at lower and mid latitudes (China, N.A. and Europe)

    • Plus: snow-cap melt run off will shift away from summer and fall when biological (and human) demand for water is greatest compared to winter and early spring

      • Annual cycle of water supply for many terrestrial and human systems will see reduced temporal buffering

      • 1/6th of the human population relies on glaciers and seasonal snowpacks for water supply

      • Over 50% of river flow dominated by snow melt in: all of Canada, NW states of US, all of Scandinavia (exc Denmark) Balkan Europe, Russia, NE China, much of Chile, SW Argentina and S of New Zealand


    Water and ice l.jpg
    Water and ice altered

    In terms of human # - most critical region: China and parts of India

    Supports 2 billion people

    Largest volume of ice outside of polar and peri-polar regions

    Nearly 70% of the Ganges’ summer flow and 50-60% of other of the regions’ major rivers: melt water


    Tops of mountains l.jpg
    Tops of mountains… altered

    • Global warming thermally determined zonation on mountains changes and rises

      • Cannot migrate above mountain summits

    • Alpine biome is 3% of the vegetated terrestrial surface – and shrinking

      • Ural Mountains

        • Temperatures risen by more than 4 C in 20th century

        • Tree lines have risen between 20 and 80 m upslope

        • Reducing regional alpine lines by 10 – 20%

    • Mountain pygmy possum (S-E Australia)

      • Habitat favored by skiers

      • Under serious threat


    Highland forests of monteverde costa rica l.jpg
    Highland forests of Monteverde, Costa Rica altered

    • 20 species of 50 anurans (frogs and toads) in a 30 km2 study area went extinct –

      • including endemic golden toad (1987)

      • Population crashes all associated with decline in dry-season mist frequency – due raising of cloud-bank base (presumed)

    • Changes behavior of animals

      • Harlequin frogs gathered near waterfalls  increased change of attack by parasitic flies  increased mortality


    A message from the frogs blaustein and dobston nature 2006 l.jpg
    ‘A message from the frogs’ altered – Blaustein and Dobston (Nature 2006)

    • The harlequin frogs of tropical America are at the sharp end of climate change. About two-thirds of their species have died out, and altered patterns of infection because of changes in temperature seem to be the cause.

    • Climate change has already altered transmission of a pathogen that affects amphibians – leading to widespread populations and extinctions

    • 67 % of the 110 species of harlequin frogs endemic to the region have died in past 20 years

    • 78-83% of extinctions occurred in unusually warm years in the tropics

    • Shifting temperatures are the ultimate trigger for the expansion of a pathogenic fungus


    A message from the frogs blaustein and dobston nature 200659 l.jpg
    ‘A message from the frogs’ altered – Blaustein and Dobston (Nature 2006)

    • “The powerful synergy between pathogen transmission and climate change should give us cause for concern about human health in a warmer world.”


    Climate change and human health l.jpg

    Climate Change altered and Human Health

    Climate change should be billed as a 'health' not 'environmental' disaster

    The researchers from George Mason University's Center for Climate Change Communication (4C), whose study was recently published in the BMC public health journal, said the health impacts of climate change had been 'dramatically under-represented' in discussions by scientists, policy-makers and NGOs who instead focused on 'geographically remote' impacts like melting ice caps in the Arctic.



    Climate change and health pathway from driving forces through exposures to potential health impact l.jpg
    Climate change and health: pathway from driving forces, through exposures to potential health impact.

    Source: Climate Change and Human Health – Risks and Reponses. Summary (WHO, 2003)


    Climate change and human health pathways l.jpg
    Climate Change and Human Health Pathways through exposures to potential health impact.


    Slide64 l.jpg

    POOR RAINS through exposures to potential health impact.

    Inadequate in volume and distribution

    Poor grass

    Poor Harvest

    People Underfed

    (Malnutrition)

    Overgrazing where grass is good

    Less meat, less milk

    Animals underfed

    Grass /vegetation cover lost

    Over-grazing, trees cut down for fuel

    Poverty

    Animal death

    LAND DEGRADATION


    Model projections l.jpg
    Model projections through exposures to potential health impact.

    • Projected impacts of heat waves

    • Average summer mortality rates attributed to hot weather episodes

    • Changes with doubling or tripling of carbon dioxide

    • -> projections of mortality can double or triple in next several decades


    What have we seen recent heat waves l.jpg
    What have we seen? through exposures to potential health impact.Recent Heat Waves

    Location Year Approx. No.

    Deaths

    Western Europe 2006 3,392*

    Europe 2003 72,000#

    India 1998 2,541^

    USA 1995 670

    USA 1993 200

    USA 1966 500

    Aust [Melbourne] 1959 145^

    ----------------------------------------------------------------------------------

    ----------------------------------------------------------------------------------

    • * Netherlands 1,000; Belgium 940.

    • # Italy 20,089; France 19,490; Spain 15,090; Germany 9,355.

    • ^ Estimation. Total probably higher.

    • India: June 2003

      • T: 122 degrees F > 1400 deaths

      • July Floods

      • Japanese B encephalitis


    Summer 2003 heat wave l.jpg
    Summer 2003 heat wave through exposures to potential health impact.

    • France, Germany, Italy, Spain, & Portugal

      • Up to 72,000 deaths

    • Temperature was 10 degrees C (18 degrees F) above 30 year average


    European heatwave 2003 l.jpg
    European Heatwave 2003 through exposures to potential health impact.


    Hotter l.jpg
    Hotter? through exposures to potential health impact.

    • Expect more extreme weather events But not all extreme weather events are attributable to CC

    • Need to know: what is expected with natural variability assuming no carbon dioxide forcing and with climate forcing from additional anthropogenic greenhouse gases

    • UK HadCM3 model: an exceptionally warm summer up to 2020 will become a normal summer by the 2040s in Europe … they projected an increase 100-fold over the next four decades


    So effects of climate change l.jpg
    So…Effects of Climate Change through exposures to potential health impact.

    • DIRECT: Thermal stresses: extremes

      • of hot or cold

    • Respiratory consequences:

      • changes in patterns of exposure to spores, moulds, etc.

    • Direct effects:

      • loss of life or health due to: storms, floods, drought


    Air pollution and climate change l.jpg
    Air pollution and climate change through exposures to potential health impact.


    Emerging infectious diseases l.jpg
    Emerging infectious diseases through exposures to potential health impact.

    • 30 diseases new to medicine since 1976

      • New diseases…

      • Old diseases…

    • As climate changes

      • Change the range at which they occur

      • Extremes affect vector populations


    Infectious diseases l.jpg
    Infectious Diseases through exposures to potential health impact.

    • Increased mean, minimum temps along with wetter winters affects the range, proliferation and behavior of vector organisms

    • Developed world populations generally have more resources to face such problems

    • Malaria currently affects 350 million people annually, 2 million deaths

    • Potential for transmission of malaria from 45% - 60% of world’s population


    Biologic response to changes in climate l.jpg
    Biologic response to changes in climate through exposures to potential health impact.

    • Global warming and wider fluctuation in weather help to spread diseases

    • Temperatures – affect growth, development and survival of microbes and the vectors

    • Weather affects the timing and intensity of disease outbreaks (McMichael et al, 2003)


    Biologic response to changes in climate infectious diseases l.jpg
    Biologic response to changes in climate: Infectious diseases through exposures to potential health impact.

    • Warmer environment and mosquitoes

      • Boost rate of reproduction

      • Increase the number of blood meal

      • Prolongs their breeding season

      • Shorten the maturation period of microbes they carry

      • Warmer winters – tick-borne lyme disease spreading northward in Sweden, US and Canada (Epstein, 2005)

    • Heavy downpours

      • Drive rodents from burrows: risk of zoonotic diseases

      • Create mosquito breeding sites

      • Faster fungal growth in houses

      • Flush pathogens and chemicals into waterways

        • Milwaukee’s cryptosporidiosis outbreak in 1993

        • Katrina’s flood: water-borne pathogens and toxins spread.


    Extreme weather events and disease clusters l.jpg
    Extreme weather events and disease clusters through exposures to potential health impact.

    • Extremes!

      • High correlation between droughts & floods and rodent-borne and mosquito-borne diseases

      • Sequence of extremes

    • Example: Hurricane Mitch (Honduras)

      • 6 feet of rain in 3 days


    Precipitation extremes l.jpg
    Precipitation extremes through exposures to potential health impact.

    • Past century average annual precipitation: 7%

    • Heavy rain events (> 2 inches/day): 14%

    • Very heavy rain events (> 4 inches/day): 20%

    • Western drought + Devastating rains


    Diseases carried by mosquitoes l.jpg
    Diseases Carried through exposures to potential health impact.By Mosquitoes

    West Nile

    Malaria

    Dengue Fever

    Yellow Fever

    West Nile (1937: Uganda. Now: Spreading across Canada)

    Wet spring. Dry, hot summer

    Climate change will

    influence spread of WNV

    And occurrences of other

    Vector diseases


    Four main types of transmission cycle for infectious diseases l.jpg
    Four main types of transmission cycle for infectious diseases

    Source: Climate Change and Human Health – Risks and Reponses. Summary (WHO, 2003)


    Does climate change have a measurable impact on health l.jpg
    Does climate diseaseschange have a measurable impact on health?

    Climate sensitivity:

    • 5% increase in diarrhoeal disease for each 1o C temperature increase

    • (developing countries only)

      Change in relative risk:

    • Projected temperature changes relative to 1961-1990, overlaid on population

    • distribution map to give per capita increase in diarrhoea risk.

      Disease burden attributable to climate change:

    • Relative risk under each scenario/time point multiplied by WHO estimates of

    • current and future 'baseline' diarrhoea burden in each region.

    • Estimated 2.4% of diarrhoea (47,000 deaths) attributable to CC in 2000, and

    • approximately 5% ( 60,000 deaths) in 2020. (World Health Report 2002)


    Slide89 l.jpg

    Primary diseases

    economic,

    technological

    social, cultural

    drivers

    An EcoHealth View

    Health impact

    Climate change will

    Impact on all these

    Relationships!!

    e.g., + UVrad

    thermal stress

    Ecosystem

    change

    +mosquitoes

    +/- food

    Environmental

    change

    Health impact

    T, soils

    Livelihood

    population

    Social, political

    Economic

    relations

    Jobs,poverty

    consumption

    Health impact

    Socio-economic

    Level of risk


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    INDIRECT: Effects of Climate Change diseases

    MANY UNCERTAINTIES

    • Alterations in range and activity of vector-borne pathogens e.g., malaria, West Nile virus, dengue

    • Possibility of new infectious disease agents

    • Changes in person-person infections including food-borne and water-borne

    • Nutritional and health consequences of local and regional changes in agricultural production

    • Consequences of sea level rise

      • Loss of home, employment, population displacement


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    Human impacts of other forms of overload diseases

    • Human environments and livelihoods deteriorate

      • Social destabilization and conflict will escalate

      • Some of the world’s poorest populations becoming more “demographically entrapped” McMichael, 1997 limited data

      • Land exceeds carrying capacity starvation, disease, fratricide

      • Rwanda prototype 1980s


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    Vector-borne diseases diseases

    • Climate change, by altering local weather patterns and by disturbing life-supporting natural systems has significant implications for human health

    • Models suggest that higher temperatures will enhance the geographic range and transmission rates of vector-borne diseases

    • Children will be disproportionately affected, as they are more prone to infection and death from parasites.


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    Food security and malnutrition diseases

    • Many of Africa’s poor are very highly dependent on climate-related factors for their livelihoods.

    • Weather disruptions exacerbated by climate change negatively impact Africa’s economic growth and food security, and thus aggravate malnutrition

    • Undernourishment is a well-studied cause of stunted physical and intellectual development and increased disease susceptibility in children.


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    Food Production diseases

    • In some countries affects nutritional status, child growth, health

    • Depletion of ocean resources unless offset by advances in aquaculture jeopardize health in developing/poor countries


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    Sea-level rise diseases

    • Displacement of coastal population

    • Predicted rise of 0.5 m would immediately inundate 10% of land in Bangladesh

    • Alters sewage and waste disposal

    • Viability of coral reefs and wetlands

    • Again affects range of disease vectors


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    Land degradation diseases

    • Absolute numbers of malnourished persons increasing

    • Many world’s fisheries overexploited

    • World loss of biodiversity

      • We have occupied, damaged or eliminated natural habitats of many species

      • Fastest loss of species ever; we may cause 1/3 of all species alive in last century to be gone before end of this century


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    Land degradation diseases

    • Agricultural productivity: to maintain food production have to resort to maintaining vigor and resilience by diversity of species to be source of genetic additives

    • A high number of medicinal drugs come from naturals; can’t be replicated in labs

      • Science continues to test many new drugs from nature each year


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    Climate Change and Environmental Justice diseases

    • Oil-related health consequences

      • Extraction: Nigeria, Ecuador, Mexico

      • Refining and Benzene

      • Utility plants and mercury

      • Air pollution and inner city truck routes

      • Economic inequities

    • Vulnerabilities – coping, adaptation

      • Restoration, prevention

      • Public health infrastructure

    • Still: No nation is immune


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    And the future? diseases

    • Further change is anticipated with further warming

    • IPCC scientific consensus

      • Warming will continue through the rest of the this century and beyond

      • Questions: how much warming and at what rate

      • Depends on future emissions of GHG

    • So what can be done?