terrestrial ecosystem response to climate change

Terrestrial Ecosystem Terrestrial Ecosystem Response to Climate Response to Climate

ChangeChange

Global Change and Effects on Terrestrial EcosystemIntroduction 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).

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

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

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

http://www.bom.gov.au/info/climate/change/gallery/9.shtml

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

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

570 505 438 408 360 286 245 208 144 66 2 10K Million years before present

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.

Global Distribution of Vegetation 18,000 years ago

conifers

tundra

taigagrassland

woodland

desert



Global Distribution of Vegetation 6,000 years ago

taigatemperate deciduous

woods & scrub

conifers

grassland desert

tundra

cold deciduous



Global Distribution of Vegetation - Present

taigatundra temperate deciduous

grassland

cold deciduous

tropical R.F.

warm mix

18 kya

9 kya

Present

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

spruce

spruce

spruce

spruce

spruce

ice sheetice

ice

ice

ice

oak

oak

oakoak

• 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

Shifts in Terrestrial Habitat18Kya

9Kya

Present

PRESENT

DAY

BIOMES

tundra

taiga

desert

temp. decd. forest

taiga

desert

desert

trop. rain

forest

grassland

temp rain

forest

scrub forest

Alaska Greenland

Ice landIce land

Siberia

Canada

Location: Regions south of the ice caps of the Arctic and extending across North America, Europe and Siberia (high mountain tops)

Yakutsk

Tundra

N. Europe

Average Temperature: -40°C to 18°C 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

Yakutsk, RussiaLocation:

62.1 N; 129 W

earthobservatory.nasa.gov

Average annual temperatureand precipitation

Temperature: -40°C to 20°C, average summer temperature is 10°C 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)

Canada Europe Asia

S.W. U.S

Beaverlodge, Alberta, Canada


Boreal Forest (Taiga)

Average annual temperatureand precipitation

55oN; 119o W

Average Yearly Temperature: Between -30°C to 30°C; 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 treesTemperate Rainforests – (CA, OR, & WA) – made up of Red wood and Sequoias

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

Four types: 1. deciduous forests2. evergreen forests3. mixed deciduous and evergreen4. temperate rain forests

Location: Eastern United States, Canada,Europe, China, and Japan

Temperate Forests

http://www.windows.ucar.edu/tour/link=/earth/forest_eco.html

Staunton, Virginia, United States38oN; 79oW


Average annual temperature and rainfall

Tropical Forests

General Characteristics:

Average Temperature: 20°C to 25°C, 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 Earth’s land surface• Produce more than 40% of Earth’s 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

3 major geographical areas:

1. America: Amazon river basin2. Africa: Zaire basin, small area of W. Africa, Eastern portion of Madagascar3. Asia: West coast of India, Assam, S.E. Asia, New Guinea and Queensland,

Australia

Tropical Rainforest

Amazon river basin Zaire

Madagascar

India S.E. Asia

Queensland

New Guinea

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

http://passporttoknowledge.com/rainforest/GEOsystem/Maps/se_asia.html

Campa Pita, Belize 15 N latitude


Tropical Forest

Average annual temperature and precipitation

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.

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 -20°C to 30°C

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

Grasslands

Ingeniera White, Argentina40oS; 6oW


Average annual temperature and rainfall

Location: Found north and south of theEquator

Temperature: Average of 38°C (day),average of -3.9°C (night)

Precipitation: About 250 mm of rain per yr

Vegetation: Cacti, small bushes, shortgrasses

Other: Perennials survive for several years bybecoming dormant and flourishing whenwater is available. Annuals are referred toas ephemerals because some can completean entire life cycle in weeks.

Deserts

El-Oasr el-Akhdar, Egypt

26oS; 30oE


Average yearly temperature and rainfall

So … what are the predictions?????

Present day

Predicted Distribution

forest

forest

grassland

grassland

arid

woodland

shrub land

shrub land woodlandgrasslandgrassland

Climate change p. 104

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

Predicted Change in BiomesLoss 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.

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.

present range

Prediction based on Prediction based on increased increased temperature temperature and decrease

precipitation

present range

Predictions of Sugar Maple in Eastern North America

overlap

predicted new growth

predicted new growth

overlap

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

Eastern slope will become drier and shift to Juniper and Sagebrush

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

Frequency of forest fires will increase, reducing total American boreal forest area.

Shifts in Terrestrial Habitat

• 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.

Potential distribution of the major world biomes under current climate conditions

Projected distribution of the major world biomes by simulating the effects of 2xCO2-equivalent concentrations www.usgcrp.gov/usgcrp/ seminars/960610SM.html

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

Boreal and Alpine Vegetation

• 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)

Predicted changes in Siberian vegetation in response to doubling of CO2

Climate change

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

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

Impact high…

climate change impact 35

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…


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

37 climate change impact

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

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

Drought


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

BUT NOT JUST DROUGHTS


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

Yemen: recent floods (October 2008)


Observed Changes in Physical and Ecological Systems (from IPCC 2001)

hydrology / sea ice animals plants study covers study based onglaciers large area remote sensing

04/19/23 44

Those at Risk 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

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

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

http://www.sciencedaily.com/releases/2005/09/050918132252.htm

Key Conclusions from IPCC

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

04/19/23 47

Phenology 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

04/19/23 48

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

Phenological Changes

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

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?

04/19/23 51

Biological communities and species shift

04/19/23 52

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

04/19/23 53

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

04/19/23 54

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

04/19/23 55

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…

04/19/23 56

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

04/19/23 57

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)

04/19/23 58

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 2006)

04/19/23 59

“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

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.

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http://www.biomedcentral.com/qc/1471-2458/10/299

http://www.biomedcentral.com/qc/1471-2458/10/299

Epidemiological Framework

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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)

Driving forces

Population dynamics

Unsustainable economic

development

Natural causes

Adaptive capacity

Mitigative capacity

Mitigation measures

Greenhouse gases (GHG)

emissions

CLIMATE CHANGE

Microbial contamination

pathways

Transmission dynamics

Agro-ecosystems, hydrology

Socioeconomics, demographics

Regional weather changes

Heatwaves

Extreme weather

Temperature

Precipitation

Health effects

Temperature-related illness and death

Extreme weather-related health effects

Air pollution-related health effects

Water and food-borne diseases

Vector-borne and rodent-borne diseases

Effects of food and water shortages

Mental, nutritional, infectious and other

health effects

Modulating influences

Health-specific adaptation measures

Research needs

Evaluation of adaptation

Climate Change and Human Health Pathways

POOR RAINS

Inadequate in volume and distribution

Poor Harvest

People Underfed

(Malnutrition)

Poor grass

Less meat, less milk Overgrazing where grass is good

Animals underfed

Over-grazing, trees cut down

for fuel

Grass /vegetation cover lostAnimal deathPoverty

LAND DEGRADATION

64

Model projections

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

65

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 2003T: 122 degrees F >

1400 deathsJuly FloodsJapanese B encephalitis

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

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European Heatwave 2003

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

04/19/23 69

So…Effects 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

Air pollution and climate change

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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

72

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 world’s population

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)

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

Milwaukee’s cryptosporidiosis outbreak in 1993 Katrina’s flood: water-borne pathogens and toxins spread.

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

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Precipitation extremes

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

82

Diseases Carried By Mosquitoes

West Nile Malaria

Dengue Fever Yellow Fever

West Nile (1937: Uganda. Now:

Spreading across Canada)

Wet spring. Dry, hot summerClimate change will

influence spread of WNVAnd occurrences of other

Vector diseases

Four main types of transmission cycle for infectious diseases

HUMANS

HUMANS

ANIMALS

ANIMALS

HUMANS

HUMANS

HUMANS

VECTOR/VEHICLE VECTOR/VEHICLE

ANIMALS

ANIMALS

HUMANS

VECTOR/VEHICLE VECTOR/VEHICLE

Anthroponoses

Direct transmission Indirect transmission

Zoonoses

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

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)

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Primary economic,

technologicalsocial, cultural

drivers

Environmentalchange

e.g., + UVrad thermal stress

Health impact

Health impact

Health impact

Ecosystemchange

+mosquitoes+/- food

Social, politicalEconomicrelations

T, soils

Jobs,povertyconsumption

Socio-economicLevel of risk

Livelihoodpopulation

An EcoHealth View

Climate change willImpact on all these

Relationships!!

INDIRECT: Effects of Climate ChangeMANY 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

Human impacts of other forms of overload 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

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.

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Food security and malnutrition

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

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

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

Land degradation

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

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; can’t be replicated in labs Science continues to test many new drugs from nature

each year

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

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And the future?

04/19/23 99

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?

terrestrial ecosystem response to climate change

Documents

reconstructing biomes

oak forests

major biomes

palaeoecological data

oak trees

different biomes

european pollen data

climate dynamics