Some of the infrared radiation Some of the infrared radiation passes through the atmosphere, passes through the atmosphere, and some is absorbed and and some is absorbed and re-emitted in all re-emitted in all directions by directions by greenhouse gas greenhouse gas molecules. The molecules. The effect of this effect of this is to warm is to warm the Earth’s the Earth’s surface and surface and the lower the lower atmosphere.atmosphere.

Some solar radiation is reflected by the

Earth and the atmosphere

Solar radiation passes through the clear atmosphere

Most radiation is absorbed by the Earth’s surface and warms it

Infrared radiation is emitted from the Earth’s Surface

The Greenhouse Effect

280

300

320

340

360

380

Carbon Dioxide ConcentrationsMauna Loa

1963 1968 1973 1978 1983 1988 1993

Par

ts p

er m

illi

on

Source: Keeling and Whorf, 1999

1958 1998

Examples of Greenhouse Gases Affected by Human Activities

CO2 CH4 N2O

Pre-industrial concentration 288 ppmv 848 ppbv 285 ppbv

Concentration in 1999 366 ppmv 1800 ppbv 312 ppbv

100 year Global Warming Potential 1 21 310

Atmospheric lifetime (years) 50-200a 12b 120

ppmv = part per million volume; ppbv = part per billion volumea No single lifetime for CO2 can be defined because of the different rates of uptake by different processes.b Defined as an adjustment time which takes into account the indirect effects of methane on its own lifetime.

Sources: IPCC 1995, CDIAC (Manua Loa, Siple Station, Law Dome “DE08”, AGAGE, and Law Dome “BHD” data)

Temperature Change and CO2 Concentrations

CO2 concentration in theatmosphere (Antarctic Ice Core)

Temperature changes compared to the present temperature

Thousands of years ago

Tem

per

atu

re C

han

ge (

o C)

-8-4-2024

150 100 50 0

200

250

300

400

500

600

700

750

CurrentLevel

CurrentLevel

-0.6

-0.4

-0.2

0

0.2

0.4

0.6

0.8

1880 1900 1920 1940 1960 1980 2000

Global Mean Land and Sea Surface Temperature: 1880-1999

Temperatures expressed relative to 1880-1997 average.Data Source: http://www.ncdc.noaa.gov/ol/climate/research/1998/anomalies/anomalies.html

Tem

per

atu

re C

han

ge (

o C)

Temperature Trends: 1901 to 1998

Red circles reflect warming; Blue circles reflect coolingAll Stations/Trends displayed regardless of statistical significance.Source: National Climatic Data Center/NESDIS/NOAA

Precipitation Trends: 1901 to 1998

Green circles reflect increasing precipitation; Brown circles reflect decreasing precipitationAll Stations/Trends displayed regardless of statistical significance.Source: National Climatic Data Center/NESDIS/NOAA

Projected Temperature

14oC

15oC

16oC

17oC

19oC

18oC

1900 1950 2000 2050 2100

Year

Global average temperature5 year average temperatureIPCC high estimateIPCC best estimateIPCC low estimate

-5 0 5 10 15 20 25

Surface Air Warming: GFDL Model Results for 2xCO2

Source: Manabe and Stouffer, 1994

Degrees (oF)

Surface Air Warming: GFDL Model Results for 4xCO2

Source: Manabe and Stouffer, 1994

-5 0 5 10 15 20 25Degrees (oF)

0 10 20 30 40 50 60

Source: Manabe and Stouffer, 1994

Percent Reduction in Summer Soil Moisture: GFDL Model Results for 2xCO2 and 4xCO2

2xCO2 4xCO2

Percent

0 1 2 3 4 5Thickness (meters)

Changes in March Sea Ice Thickness

Control 4xCO2

Source: Manabe and Stouffer, 1994

Health ImpactsWeather-related MortalityInfectious DiseasesAir Quality-Respiratory Illnesses

Agriculture ImpactsCrop yieldsIrrigation demands

Water Resource ImpactsChanges in water supplyWater qualityIncreased competion for waterImpacts on Coastal AreasErosion of beachesInundate coastal landsCosts to defend coastal communities

Forest ImpactsChange in forest compositionShift geographic rangeof forestsForest Health and Productivity

Species and Natural AreasShift in ecological zonesLoss of habitat and species

Potential Climate Change Impacts

Climate Changes

Sea Level Rise

Temperature

Precipitation

Mediating Process

Health Outcomes

CLIMATECHANGE:TEMPERATURE,PRECIPITATION,AND WEATHER

Ways Climate Change Can Affect Human Health

Thermal extremes (e.g., heatwaves)

Other extreme weather events(floods, storms, etc.)

DISTURBANCES OFECOLOGICAL SYSTEMS

Geographic range and activity of vectors and infective parasites

Altered local ecology of water-borneand food-borne infective agents

Altered food productivity, and associated pests and diseasesSea level rise, population displace-ment, and damage to infrastructure

Levels air pollution, including pollens and spores

INDIRECT

DIRECTChanges in heat- and cold-relatedillnesses and deaths

Deaths, injuries, psychologicaldisorders; damage to public health infrastructure

Geographic ranges and incidence of vector-borne diseases

Regional malnutrition and hunger, impaired child growth and development

Changed incidence of diarrheal andcertain other infectious diseases

Injuries, risks of infectious disease (due to migration, crowding, contaminated drinking water), psychological disordersAsthma and allergic disorders; acute and chronic respiratory disorders and deaths

Source: Adapted from IPCC, 1995.

Days from May to August

0 10 20 30 40 50 60 70 80 100 110 120 130900

1

2

3

4

5

6

7

8

9

10

Sta

nd

ard

ized

Mor

tali

ty

Rat

e p

er 1

00,0

00

Deaths Associated with the July 1966 Heat Wave, New York City

Source: WHO, 1996

0

20

40

60

80

100

Atl

anta

Cin

cin

nat

i

Det

roit

Los

An

gele

s

Min

nea

pol

is

Ph

ilad

elp

hia

San

Fra

nci

sco

Current UKMO GFDL

Dal

las

Ch

icag

o

Kan

sas

Cit

y

Mem

ph

is

New

Yor

k

St.

Lou

is

Probability that 4 Days in June Exceed City’s Temperature Threshold

Source: Probabilities of Temperature Extremes in the U.S.A, Version 1, NCDC, 1999; Kalkstein, 1989

0

150

300

450

600

750

050

100150200250300

0102030405060

050

100150200250300

0

4080

120

160

200

0

250

500

750

1000

1250

1500

Average Annual Excess Weather-Related Mortality for 1993, 2020 and 2050 Climate

GFDL Climate Change Scenario

Los Angeles

New York City

DallasAtlanta

Sources: Kalkstein and Green (1997); Chestnut et al.(1995)

Phoenix

Note: Includes both summer and winter mortality. Assumes full acclimation to changed climate. Includes population growth.

Chicago

1993

2020

2050

Population Likelihood ofat risk Present altered distribution

Disease Vector (millions) Distribution with warming

Malaria mosquito 2400 (sub)tropics Schistosomiasis water snail 600 (sub)tropics Filariasis mosquito 1094 (sub)tropics Onchocerciasis black fly 123 Africa/Latin (river blindness) AmericaAfrican trypano- tsetse fly 55 tropical Africa somiasis(sleeping sickness)Dengue mosquito 2500 (sub)tropics Yellow fever mosquito 450 tropical South

America & Africa

Human Health: Potential Spread of Vector-Borne Diseases

Source: WHO (1996)

- Likely - Very Likely - Highly Likely

Adaptation and Other Health Concerns• Measures to minimize health impacts include:

– improved monitoring, surveillance, and control programs– disaster preparedness and response capability– wider use of protective technologies (sea walls and levees, water purification, vaccination)– public education– early warning systems, improved use of climate forecasts

• Technical solutions may themselves pose health risks– e.g., pesticides to control for insect vectors

• Potential reductions in biodiversity may result in losses of substances that can cure disease or relieve pain

Emissions

• Anthropogenic• Biogenic

Interactions Between Climate Change and Air Quality

Concentrations

Secondary PollutantsAffected by WeatherConditions• Temperature• Precipitation• Windspeed and • Direction

Health Responses

Combined Exposure to Stressful Weatherand Air Pollution

Parameter

Maximum Daily Temperature >= 80oF

Average Daily Wind Speed < 10.5 mph

Precipitation None between 7am and 3pm

Solar Radiation >410 langleys/day

Threshold Value

Source: Kolaz and Swinford, 1990

Meteorological Conditions Present on Ozone Exceedance Days

(Chicago, 1977-1980)

Notes: Present on 81% of ozone exceedance days in the Chicago area. Remaining exceedance days met 3 of 4 criteria.

Health EffectsAcute Respiratory Illnesses and Asthma Aggravation PM, O3, NO2, SO2

Respiratory Hospital Admissions PM, O3

Cardio-Pulmonary Effects (e.g., stroke) CO, PbDevelopment of Chronic Respiratory Disease PM, O3

Cancer Air ToxicsPremature Mortality PM, O3, SO2, PbReproductive Effects Air Toxics

Direct Economic EffectsLost Work Days PM, O3

Decreased Worker Productivity O3

Material Damage & Soiling PM, O3, SO2

Crop Yield Loss O3

Commercial Fishery Harvest Loss Nitrogen DepositionForestry Yield Loss O3

Ecological EffectsAcidic Depostion SO2, NO2

Eutrophication Nitrogen DepositionWetland Preservation Nitrogen Deposition, SO2

Known Adverse Effects of Air Pollutants

Regional 50% Probability Estimates of Sea Level Rise in 2100 and 2200

Portland, ME19 43

New York, NY22 48

Seattle, WA19 42

San Fransisco, CA15 36

Los Angeles13 32

Charleston, SC25 53

Grand Isle, LA55 112

Miami Beach, FL20 44

Source: U.S. EPA (1995).

Estimates are in inches.

U.S. Coastal Lands at Risk from a 20-inch Sea Level Rise in 2100

Source: U.S. EPA (1989).

-1000

0

1000

2000

3000

4000N

orth

east

Mid

-Atl

anti

c

Sout

hA

tlan

tic

S &

WF

lori

da

Lou

isia

na

Res

t of

Gul

fC

oast W

est

Drylands

Wetlands

Sq

uar

e M

iles

Blackwater National Wildlife Refuge (Maryland)

1938

1980N

Trapping Unit

MarshOpen WaterUpland

1 0 1 2 3

Kilometers

Source: U.S. EPA, 1989.

Louisiana: Shoreline Change after a 20-Inch Rise in Sea Level

Lake CharlesLafayette

Baton Rouge

Morgan City

Houma

NewOrleans

Gulf of Mexico

Land Lost

Water Resources: Regional Vulnerability

Source: U.S. EPA (1989)

UseUsePacificPacific

NorthwestNorthwest CaliforniaCalifornia

AridAridWesternWestern

RiverRiverBasinsBasins

GreatGreatPlainsPlains

GreatGreatLakesLakes MississippiMississippi

South-South-easteast

North-North-easteast

Irrigation

Thermal power

Industrial

Municipal/ domestic

Water quality

Navigation

Flood control

Hydropower

Recreation

Changes in Agricultural Yields 2.5oF Warming; 7% Increase in Precipitation; 530 ppmv CO2

Change in Wheat Yield Change in Corn Yield

Percent Change

-30 -20 -10 0 +30 >+30+20+10

Source: Rosenzweig, 1995

Agricultural Resources: Potential Change inGrain Yield due to Doubled CO2

Based on GISS model; physiological CO2 effects included

Source: Rosenzweig and Hillel (1993)

-30% 10%-10%Percent of Change in Yield

30%

-100

0

100

200

300

400

Agricultural Resources: Increase in Global Population at Risk from Hunger

Without Adaptation With Adaptation

Change in Number of People at Risk of Hunger

Source: Strzepak and Smith (1995)

Mill

ion

s GISS

GFDLUKMO

Current Climate

OSU Climate

UKMO Climate

Conifer ForestBroadleaf ForestSavanna/WoodlandShrub/WoodlandGrasslandArid Lands

Change in PotentialVegetation for 2050Climate Scenario

Source: Neilson, 1995

Current and Projected Ranges of Sugar Maple

Source: Redrawn from Davis and Zabinski, 1992

Present Range Overlap Predicted Range

Prediction based on increased temperature

Prediction based on increased temperature and moisture reduction

Loss of Habitat for Brown Trout from a Doubling of CO2 - 2050

Not includedin analysis *

1-49% Loss 50-100% Loss

Source: EPA, 1995 GFDL Climate Change Scenario

* Dual screening criteria used for inclusion: 1) Thermal modeling predicts suitability and 2) Fish presence in 10% or more of State’s water bodies.

Low Density

Medium Density

High Density

Source: Schneider and Root, 1997.

Bobolink Bird Distribution

IPCC Second Assessment

• Climate has changed over the past century– Global mean surface air temperature has increased .5-1o F– Global sea level has risen 4-10 inches– Global precipitation over land has increased 1%

• “The balance of evidence suggests a discernible human influence on global climate” (IPCC, 1995)

• Climate is expected to continue to change in the future– Projected temperature increase of 3.6oF by 2100 (1.8-6.3oF)– Projected sea level rise of 20 inches by 2100 (6-38 inches)– Likely increase in precipitation intensity

IPCC Second Assessment Report Conclusions

There are still many uncertainties

• Future emissions, biogeochemical cycling of GHGs and aerosols, and future concentrations

• Representation of climate feedback processes in models– clouds, convection and precipitation, sea ice, vegetation,

oceans

• Detection and attribution

• Non-linear responses (“Surprises”) and severe storms

• Regional patterns of change