Global Change

(1)

Global Change

Unit 10

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• Global change- any chemical, biological or

physical property change of the planet. Examples include cold temperatures causing ice ages.

• Global climate change- changes in the climate of the Earth.

• Global warming- one aspect of climate change, the warming of the oceans, land masses and atmosphere of the Earth.

Global Change

(3)

• When radiation from the sun hits the atmosphere, 1/3 is reflected back.

• Some of the UV radiation is absorbed by the ozone layer and strikes the Earth where it is converted into low-energy infrared radiation.

• The infrared radiation then goes back toward the atmosphere where it is absorbed by

greenhouse gasses that radiate most of it back to the Earth.

The Greenhouse Effect

(4)

• Water vapor

• Carbon dioxide

• Methane

• Nitrous oxide

• Ozone

Greenhouse Gases

(5)

greenhouse gases (the big

5)

(6)

• Volcanic eruptions- mainly carbon dioxide

• Methane – from decomposition

• Nitrous oxide- from denitrification

• Water vapor

Natural Greenhouse Gases

(7)

Greenhouse Effect

greenhouse effect

(8)

Anthropogenic Sources GHGs

deforestation (CO

₂

)

fossil fuel combustion (CO

₂

)

cattle digestive gas emissions (methane)

(9)

Anthropogenic Sources GHGs

(10)

Average temperature over past 900,000 years

Thousands of years ago

Average surface temperature (°C)

900 800 700 600 500 400 300 200 100 Present

9 10 11 12 13 14 15 16 17

900,000 years

(11)

Temperature change over past 22,000 years

Years ago

Temperature change (°C)

20,000 10,000 2,000 1,000 200 100 Now

-5 -4 -3 -2 -1 0 1 2

End of last ice age

Agriculture established

Average temperature over past 10,000 years = 15°C (59°F)

22,000

(12)

Temperature change over past 1,000 years

Year

Temperature change (°C)

1000 1100 1200 1300 1400 1500 1600 1700 1800 1900 2000 2101 -1.0

-0.5 0.0 0.5 1.0

1000

(13)

Average temperature over past 130 years

Year

Average surface temperature (°C)

1860 1880 1900 1920 1940 1960 1980 2000 2020

13.6 13.8 14.0 14.2 14.4 14.6 14.8 15.0

130 years

(14)

Natural Climate Variation Natural factors affecting temp?

volcanic eruptions

“wobble” on axis (Milankovitch cycles) variations in cloud cover

ocean currents Evidence?

ice core data

fossil record of species (plant & animal)

(15)

Antarctica Greenland

Greenland

Ocean currents distribute

energy

(16)

Grab white boards Take a deep breath….

What gases did you just breathe in???

What % of

each?

(17)

Nitrogen 78%

Oxygen 21%

All rest < 1%

CO

₂

H

₂

O CO

etc…

(18)

(19)

Carbon dioxide

Temperature

change End of last ice age

160 120 80 40 0

Thousands of years before present Concentration of carbon dioxide in the atmosphere (ppm)

180 200 220 240 260 280 300 320 340 360 380

–10.0 –7.5 –5.0 –2.5 0 +2.5

Variation of temperature (˚C) from current level

CO

₂

&

temp

(20)

Global Warming

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Oceans 5%

Bare sand 30–60%

Grass 15–25%

Clouds 50–55%

Snow 80–90%

City 10–15%

Forest 5%

albedo

(22)

simplified climate model

Troposphere

Aerosols

Greenhouse gases

Warming from decrease

Cooling from increase

CO₂ removal by plants and soil organisms

CO₂ emissions from land cleaning, fires, and decay

Heat and CO₂ removal

Heat and CO₂ emissions

Ice and snow cover

Natural and human emissions

Land and soil biotoa

Shallow ocean

Long-term storage

Deep ocean

(23)

(24)

permafrost melting

glacier

melting

(25)

Ice & sea level

(glaciers, pack

ice, ice caps,

fresh water)

(26)

Pack ice predictions

(27)

Northwest Passage

(28)

KMT & thermal expansion

(29)

Results of warming Ocean acidification

Coral bleaching

(30)

Results of warming

Storm Intensity

(31)

Results of warming

Increased incidence of El Nino

(change in drought, flood patterns) Dust storms

Forest Fires

(32)

Results of warming

Change in infectious disease patterns

(33)

Major irrigation well

Well contaminated with saltwater

Saltwater Intrusion

Normal Interface Fresh

groundwater aquifer

Interface Interface

waterSalt

Sea Level Water

table

Saltwater intrusion

(34)

What can we do?

Reduce deforestation Plant trees

Reduce fossil fuel combustion Conserve energy

Switch to renewable fuel sources

Eat lower on food chain!

(35)

Global Biodiversity

(36)

Species Extinction

Locally:

Gone where once found, still in other places.

Ecologically:

Too few left to play ecological role

Globally (biologically): Gone. Forever.

(37)

Designations:

Endangered species:

So few, could soon become extinct.

Threatened species:

Still abundant but is likely to become endangered soon.

Generally K-selected species

(38)

Hawksbill sea turtle Giant panda Black-footed

ferret Whooping

crane Northern

spotted owl Blue whale

Mountain gorilla Florida

panther California

condor Black

rhinoceros

Endangered Species

(39)

% of species involved in “6

^th

Mass

Extinction”

(40)

IMPORTANCE OF WILD SPECIES

•ecological services

(aka instrumental value)

•economic worth (ecotourism)

•inherent right to exist

(intrinsic value)

(41)

HIPPO

causes of premature extinction –H

–I

–P

–O

(42)

HIPPO

•causes of premature extinction

–H abitat destruction, degradation, and fragmentation

–I –P –P –O

(43)

HIPPO

–I nvasive species –P

–P –O

(44)

INVASIVE SPECIES

Non-native r-selected

Kudzu vine was introduced in the southeastern U.S. to

control erosion. It has taken over native species habitats.

(45)

INVASIVE SPECIES

• introduced intentionally.

Figure 11-11 Figure 11-11

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INVASIVE SPECIES

• introduced unintentionally.

Figure 11-11 Figure 11-11

(47)

HIPPO

–I nvasive species

–P opulation growth of humans –P

–O

(48)

HIPPO

–P opulation growth of humans –P ollution

–O

(49)

HIPPO

–H abitat destruction, degradation, and fragmentation

–P opulation growth of humans –P ollution

–O verharvest, overconsumption, overexploitation

(50)

CITES

Convention on International Trade of Endangered Species

1975

169 countries

lists 900 species that cannot be commercially traded.

(51)

Endangered Species Act (ESA)

ESA forbids federal agencies

(besides defense department) to

carry out / fund projects that would jeopardize an endangered species.

ESA : illegal to hunt / kill / collect

endangered or threatened species.

(52)

Maintaining species

•Gene banks, botanical gardens

(raise & store species, often lack funding & storage space)

•Zoos & aquariums

preserve individuals for reintroduction lack of: space, funding, genetic

diversity

(53)

AQUATIC BIODIVERSITY

Greatest biodiversity coral reefs

estuaries

abyssal zone

Provide ecological and economic

services.

(54)

Kelp

Hogfish

Cobia

Pacific sailfish Carrageen

Yellow jack Batfish

Moray

Red snapper Red algae

Striped drum Angelfish Bladder kelp

Sea lettuce Orange roughy Chinook salmon

Devilfish Great barracuda

Laminaria

Porcupine fish

Sockeye salmon

Grouper

Dulse Chilean sea bass

Marine

Examples

(55)

Bulrush

Bluegill White bass

Brook trout White waterlily

Water lettuce

Rainbow trout

Muskellunge

Bowfish Water hyacinth

Rainbow darter

Bladderwort

Black crappie

White sturgeon

Yellow perch

Largemouth black bass

Walleyed pike

American smelt

Eelgrass

Longnose gar Duckweed

Common piranha

Carp

African lungfish Egyptian white lotus Channel catfish

Velvet cichlid

Freshwater

Examples

(56)

HUMAN IMPACTS

–approx 20% coral reefs gone –past 100 years sea levels

risen 10-25 cm.

–33% mangrove forests

destroyed for shipping lanes.

(57)

HIPPO in the ocean

Bio-invaders caused 66% of recent fish extinctions in the U.S.

50% world populations lives near a coast

80% of ocean pollution is from land- based human activities.

(58)

Overfishing

75% fish species overfished

-Big fish are

becoming scarce

-Smaller fish are next - 30% of all fish catch is bycatch

(59)

Fish farming in cage

Trawler fishing

Spotter airplane

Sonar Trawl flap

Trawl lines

Purse-seine fishing

Trawl bag

Fish school

Drift-net fishing Long line

fishing Lines with

hooks

Fish caught by gills Deep sea

aquaculture cage

Float Buoy