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Terrestrial Ecosystem Response to Climate Change

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Title: Terrestrial Ecosystem Response to Climate Change


1
Terrestrial Ecosystem Response to Climate Change
2
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).

3
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 natures sources of CO2 are self
regulating that which is released will be used
again Anthropogenic carbon not part of natures
cycle is in excess
4
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

5
  • 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/. ../ES2020we16.jpg
6
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7
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 12185-194.
8
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 12185-194.
9
Global Distribution of Vegetation - Present
taiga
tundra
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 12185-194.
10
Shifts in Terrestrial Habitat
18 kya
18Kya
  • 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

ice
ice sheet
oak
spruce
spruce
9 kya
9Kya
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
11
tundra
PRESENT DAY BIOMES
taiga
taiga
desert
temp. decd. forest
desert
grassland
trop. rain forest
scrub forest
desert
temp rain forest
12
Tundra
Location  Regions south of the ice caps of the Arctic and extending across North America, Europe and Siberia (high mountain tops)
Greenland
Alaska
Siberia
N. Europe
Yakutsk
Average Temperature -40C to 18C Average Precipitation  150 to 250 mm of rain per year Type of vegetation  Almost no trees due to short growing season and permafrost lichens, mosses, grasses, and shrubs
Canada
Ice land
13
Average annual temperature and precipitation
Yakutsk, Russia Location  62.1 N 129 W
earthobservatory.nasa.gov
14
Temperature  -40C to 20C, average summer temperature is 10C Precipitation 300 to 900 millimeters of rain per year Vegetation  Coniferous-evergreen trees  Location  Canada, Europe, Asia, and the United States Other  Coniferous forest regions have cold, long, snowy winters, and warm, humid summers well-defined seasons, at least four to six frost-free months
Boreal Forest (Taiga)
Europe
Asia
Canada
S.W. U.S
15
Boreal Forest (Taiga)
Average annual temperature and precipitation
Beaverlodge, Alberta, Canada

55oN 119o W

earthobservatory.nasa.gov
16
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
Average Yearly Temperature  Between -30C to 30C hot summers, cold winters sunlight varies between seasons  Average Yearly Precipitation  750 to 1,500 mm of rain per year Vegetation  Deciduous - Broadleaf trees (oaks, maples, beeches), shrubs, perennial herbs, and mosses. Evergreen (N. America) Spruce, Hemlock, Pine and Fir trees Temperate Rainforests (CA, OR, WA) made up of Red wood and Sequoias 
www.windows.ucar.edu/.../ earth/forest_eco.html
17
Average annual temperature and rainfall
Staunton, Virginia, United States 38oN 79oW

earthobservatory.nasa.gov
18
Tropical Forests
General Characteristics Average Temperature 20C to 25C, must remain warm and frost-free Average Precipitation 2,000 to 10,000 millimeters of rain per year Average Humidity Between 77 88 Types of Vegetation  Large trees reaching up to 240 feet, have the most diverse trees than any other biome vines, orchids, ferns Tropical rainforests Cover less than 6 of Earths land surface Produce more than 40 of Earths oxygen Contain more than half of all the worlds plants and animals ¼ of all medicines come from rainforest plants Scientists believe more than 1400 tropical plants thought to be potential cures to cancer
19
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/rain
forest/GEOsystem/Maps/se_asia.html, (3/18/02)
20
Campa Pita, Belize 15 N latitude
Tropical Forest
Average annual temperature and precipitation


earthobservatory.nasa.gov
21
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.

22
Grasslands
Location The prairies of the Great Plains of North America, the pampas of South America, the veldt of South Africa, the steppes of Central Eurasia, and surrounding the deserts in Australia Temperature Dependent on latitude, yearly range can be between -20C to 30C Precipitation About 500 to 900 mm of rain per year Vegetation Grasses (prairie clover, salvia, oats, wheat, barley, coneflowers)     Other Found on every continent except Antarctica  
23
Average annual temperature and rainfall
Ingeniera White, Argentina 40oS 6oW

earthobservatory.nasa.gov
24
Location Found north and south of the Equator Temperature  Average of 38C (day), average of -3.9C (night) Precipitation About 250 mm of rain per yr Vegetation Cacti, small bushes, short grasses Other  Perennials survive for several years by becoming dormant and flourishing when water is available. Annuals are referred to as ephemerals because some can complete an entire life cycle in weeks.
Deserts
25
Average yearly temperature and rainfall
El-Oasr el-Akhdar, Egypt 26oS 30oE

earthobservatory.nasa.gov
26
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
27
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.
28
Predictions of Sugar Maple in Eastern North
America
predicted new growth

predicted new growth
  • 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.

overlap
overlap
present range
present range
Prediction based on Prediction
based on increased increased temperature
temperature and decrease
precipitation
29

More Predictions
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
30
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31
Shifts in Terrestrial Habitat
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
32
Boreal and Alpine Vegetation
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
33
Grasslands and Shrub Lands
  • 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

34
Impacts on Lebanon?
  • 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

35
Impact high
  • 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

36
The Arab region will
  • 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

37
Impact on freshwater sources
38
Status of freshwater here
  • 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

39
First order impacts
  • 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

40
Drought
41
Drought frequency
  • 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

42
But not just droughts
43
Yemen recent floods (October 2008)
  • Dubbed the 'Manhatten of the desert', Shibam's
    2,000-year-old mud-brick buildings are in danger
    of collapsing after recent floods

44
Observed Changes in Physical and Ecological
Systems (from IPCC 2001)
hydrology / sea ice animals
plants study covers study based
on glaciers
large area
remote sensing
45
Those at Risk
  • Northern countries (Russia, Sweden, Finland) ½ of
    existing terrestrial habitats at risk
  • In Mexico, its 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

46
  • 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
47
Key Conclusions from IPCC
  • Recent Regional Climate Changes, particularly
    Temperature Increases, have Already Affected Many
    Physical and Biological Systems
  • (high confidence, or
    gt67 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

48
Phenology
  • Phenology the study of a plant or animals
    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

49
Phenological Changes


  • 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

50
Phenological Changes
Penuelas J and Filella I 2001. Response to a
warming world. Science 294 793 795
51
Important to know the particular species
requirements
  • 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?

52
Biological communities and species shift
  • 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 todays 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

53
Arctic lakes
  • 1997 - 2004 decline of 1170 large lakes (gt 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

54
Mountain snow and ice
  • 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

55
Water and ice
  • 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

56
Tops of mountains
  • 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

57
Highland forests of Monteverde, Costa Rica
  • 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

58
A message from the frogs 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

59
A message from the frogs 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.

60
Climate Change 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.

61
Epidemiological Framework
62
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)
63
Climate Change and Human Health Pathways
64
POOR RAINS
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
Animal death
Poverty
LAND DEGRADATION
65
Model projections
  • Projected impacts of heat waves
  • Average summer mortality rates attributed to hot
    weather episodes
  • Changes with doubling or tripling of carbon
    dioxide
  • -gt projections of mortality can double or triple
    in next several decades

66
What have we seen?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 gt 1400
deaths July Floods Japanese B encephalitis
67
Summer 2003 heat wave
  • France, Germany, Italy, Spain, Portugal
  • Up to 72,000 deaths
  • Temperature was 10 degrees C (18 degrees F) above
    30 year average

68
European Heatwave 2003
69
Hotter?
  • 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

70
SoEffects of Climate Change
  • 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

71
Air pollution and climate change
72
Emerging infectious diseases
  • 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

73
Infectious Diseases
  • 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 worlds population

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Biologic response to changes in climate
  • 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)

80
Biologic response to changes in climate
Infectious diseases
  • 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
  • Milwaukees cryptosporidiosis outbreak in 1993
  • Katrinas flood water-borne pathogens and toxins
    spread.

81
Extreme weather events and disease clusters
  • 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

82
Precipitation extremes
  • Past century average annual precipitation 7
  • Heavy rain events (gt 2 inches/day) 14
  • Very heavy rain events (gt 4 inches/day) 20
  • Western drought Devastating rains

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Diseases Carried 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
85
Four main types of transmission cycle for
infectious diseases
Source Climate Change and Human Health Risks
and Reponses. Summary (WHO, 2003)
86
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Does climate change 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)

89
Primary 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
90
INDIRECT Effects of Climate Change
  • 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

91
Human impacts of other forms of overload
  • Human environments and livelihoods deteriorate
  • Social destabilization and conflict will escalate
  • Some of the worlds poorest populations becoming
    more demographically entrapped McMichael, 1997
    limited data
  • Land exceeds carrying capacity? starvation,
    disease, fratricide
  • Rwanda prototype 1980s

92
Vector-borne 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.

93
Food security and malnutrition
  • Many of Africas poor are very highly dependent
    on climate-related factors for their livelihoods.
  • Weather disruptions exacerbated by climate
    change negatively impact Africas 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.

94
Food Production
  • 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

95
Sea-level rise
  • 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

96
Land degradation
  • Absolute numbers of malnourished persons
    increasing
  • Many worlds 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

97
Land degradation
  • 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 cant be replicated in labs
  • Science continues to test many new drugs from
    nature each year

98
Climate Change and Environmental Justice
  • 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

99
And the future?
  • 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?
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