Upload
tertius-aric
View
82
Download
0
Tags:
Embed Size (px)
DESCRIPTION
Climate Change and Ozone Loss. G. Tyler Miller’s Living in the Environment 14 th Edition Chapter 21. Key Concepts. Changes in Earth’s climate over time. Factors affecting climate. Possible effects of global warming. Adapting to climate change. Human impacts on the ozone layer. - PowerPoint PPT Presentation
Citation preview
Climate Change and Ozone LossClimate Change and Ozone Loss
G. Tyler Miller’sLiving in the Environment
14th Edition
Chapter 21
G. Tyler Miller’sLiving in the Environment
14th Edition
Chapter 21
Key ConceptsKey Concepts
Changes in Earth’s climate over time Changes in Earth’s climate over time
Factors affecting climate Factors affecting climate
Possible effects of global warming Possible effects of global warming
Adapting to climate change Adapting to climate change
Human impacts on the ozone layer Human impacts on the ozone layer
Protecting and restoring the ozone layer Protecting and restoring the ozone layer
Average temperature over past 900,000 years
Thousands of years ago
Ave
rag
e su
rfac
e te
mp
erat
ure
(°C
)
900 800 700 600 500 400 300 200 100 Present9
10
11
12
13
14
15
16
17
Past Climate Changes
Temperature change over past 22,000 years
Years ago
Tem
per
atu
re c
han
ge
(°C
)
20,000 10,000 2,000 1,000 200 100 Now
-5
-4
-3
-2
-1
0
1
2
End oflast iceage
Agriculture established
Average temperature over past10,000 years = 15°C (59°F)
Past Climate Changes
Temperature change over past 1,000 years
Year
Tem
per
atu
re c
han
ge
(°C
)
1000 1100 1200 1300 1400 1500 1600 1700 1800 1900 2000 2101
-1.0
-0.5
0.0
0.5
1.0
Average temperature over past 130 years
Year
Ave
rag
e su
rfac
e te
mp
erat
ure
(°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
Recent trends in global temperatures
IPCC
1988 UN and the World Meteorological Organization established the (IPCC) Intergovernmental Panel on Climate Change to document past climate change and project future climate change.
A network of over 2,000 leading climate experts from 70 nations.
Table 21-1Page 464
Table 21-1 Major Greenhouse Gases from Human Activities
Greenhouse Gas
Carbon dioxide (CO2)
Methane (CH4)
Nitrous oxide (N2O)
Chlorofluorocarbons(CFCs)*
Hydrochloro-fluorocarbons (HCFCs)
Hydrofluorocarbons(HFCs)
Halons
Carbon tetrachloride
Average Time in the Troposphere
100–120 years
12–18 years
114–120 years
11–20 years (65–110 years in stratosphere)
9–390
15–390
65
42
Human Sources
Fossil fuel burning, especially coal (70–75%), deforestation, and plant burning
Rice paddies, guts of cattle and termites, landfills, coal production, coal seams, and natural gas leaks from oil and gas production and pipelines
Fossil fuel burning, fertilizers, livestock wastes, and nylon production
Air conditioners, refrigerators, plastic foams
Air conditioners, refrigerators, plastic foams
Air conditioners, refrigerators, plastic foams
Fire extinguishers
Cleaning solvent
Relative Warming Potential (compared to CO2)
1
23
296
900–8,300
470–2,000
130–12,700
5,500
1,400
The Greenhouse EffectThe Greenhouse Effect
Fig. 6-14 p. 110
Climate Change and Human Activities
Increased use of fossil fuelsIncreased use of fossil fuels
Deforestation Deforestation
Global warmingGlobal warming
Melting icecaps and glaciersMelting icecaps and glaciers
Rising sea levelRising sea level
Global WarmingGlobal Warming
Svante Arrhenius first speculated in 19th centuryCurrent Causes Deforestation Greenhouse Gas Levels
Burning of Fossil FuelsMain villain is currently Carbon Dioxide
(CO2)
DeforestationDeforestation
Deforestation - USDeforestation - US
About one half of the forests that covered the Earth are gone
Since 1600, 90% of the U.S. forests have been cleared away
Deforestation - RainforestsDeforestation - Rainforests
One football field of rainforest is lost every 1.4
seconds
Results of Results of DeforestationDeforestation
Loss of trees’ ability to remove CO2
Decaying trees release CO2 and methane 25% of global GHG emissions
Fallen trees are often burnt which releases CO2 Accounts for 20% of global CO2 emissions
Deforestation the largest source of emissions in developing countries
Greenhouse Greenhouse EffectEffect
Greenhouse EffectGreenhouse EffectCertain gases in the Earth’s atmosphere trap energy from the sun carbon dioxide – water vapor methane – nitrous oxide
Without these gases, the Earth’s average temperature would be about 60ºF colder
These gases are Greenhouse GasesGreenhouse Gases
Global WarmingGlobal Warming
EvidenceEvidence
COCO22 and Temperature and Temperature
Five Warmest Years on Five Warmest Years on RecordRecord
1.1. 20052005
2.2. 19981998
3.3. 20022002
4.4. 20032003
5.5. 20062006
Since 1980, the Earth has experienced 19 of its 20 Since 1980, the Earth has experienced 19 of its 20 hottest years on recordhottest years on record
EvidenceEvidence
CO2 and Temperature
GlaciersGlaciers
Portage Glacier- near Anchorage Alaska- 1950/2001
Rhone glacier in the Kanton of Valais, Switzerland 1859 / 2001
Grinnell glacier, Glacier National Park, USA 1911 / 2000
Glacier Ururashraju, at about 15,000 feet in Cordillera Blanca of Peru 1986 / 1999
20042004
GlaciersGlaciers
Have been shrinking throughout the 20th Century
Loss of glaciers in South America and Asia glaciers is particularly rapid and will threaten the water supplies of millions of people
EvidenceEvidence
CO2 and Temperature
Glaciers
Polar IcePolar Ice Arctic Antarctic Greenland
Arctic IceArctic Ice
Arctic IceArctic IcePerennial ice may be 10 or more feet thick
New ice is only one to seven feet thick
Since 1970 10% loss of ice cover per decade
Albedo EffectAlbedo Effect
Albedo, or reflectivity
Fig. 21-17 p. 480 Slide 14Slide 14Slide 14Slide 14Slide 14Slide 14Slide 14Slide 14Slide 14Slide 14Slide 14Slide 14Slide 14Slide 14Slide 14Slide 14Slide 14Slide 14Slide 14
Oceans 5%
Bare sand 30–60%
Grass 15–25%
Clouds 50–55%
Snow 80–90%
City 10–15%
Forest 5%
Figure 21-7Page 468
NASA Sees Rapid Changes in NASA Sees Rapid Changes in Arctic Sea IceArctic Sea Ice
NEWS RELEASE: September 13, 2006
From 1970 until 2000 there was a 10 percent decrease in Arctic perennial sea ice every decadeBetween 2004 and 2005 the ice shrunk abruptly by 14 percent14 percent
PermafrostPermafrost
PermafrostPermafrostWhere soil over 1-meter down never thawsAbout 10% of Earth’s surface has permafrostTundra and taiga are characterized by extreme cold 24 hours of sun during the summer Huge amount of vegetation grows
In the last 11,000 years, the permafrost has not thawed None of the vegetation has decayed Decay releases CO2 and methane
PermafrostPermafrostAlaska permafrost temperature has increased 0.5° to 1.5° C since 1980, Serious effects include forest damage sinking roads and buildings eroding tundra riverbanks changes in tundra vegetation increased carbon dioxide and
methane emissions from thawed peat.
PermafrostPermafrostEstimates of billions of tons of methane Double existing
methane in atmosphereMethane is 20 to 60 times as strong of a greenhouse gas as CO2 10 to 25% increase in
global warming
Antarctic IceAntarctic Ice
AntarticaAntartica
Land mass covered by multiple glaciers
Glaciers average 8000 feet thick
Represents 10% of all landmass on Earth
MoulinsMoulins
Rivers of water about 10 meters in diameter that flow through the glacierBring melted water below the glaciers
Series of Series of MoulinsMoulins
Antarctica MeltingAntarctica Melting
If all of the ice in the glaciers If all of the ice in the glaciers of Antarctica melt the oceans of Antarctica melt the oceans
will risewill rise
200 feet200 feet
Greenland IceGreenland Ice
Greenland Ice MeltGreenland Ice Melt
Glaciers located on three islands
Greenland loses 20% more ice than it gains each year
If all of the ice melts – oceans will rise 23 feet
If moulins work like those in Antarctica…
EvidenceEvidence
CO2 and TemperatureGlaciersPolar Ice Arctic Antarctic Greenland
Weather SeverityWeather Severity
DroughtsDroughtsThe 1999-2002 national drought was one of the The 1999-2002 national drought was one of the three most extensive droughts in the last 40 yearsthree most extensive droughts in the last 40 years
In 2002, the Western United States experienced its In 2002, the Western United States experienced its second worst wildfire season in the last 50 years; second worst wildfire season in the last 50 years; more than 7 million acres burnedmore than 7 million acres burned
The period from April through June of 1998 was The period from April through June of 1998 was the driest three-month period in 104 years in the driest three-month period in 104 years in Florida, Texas, and LouisianaFlorida, Texas, and Louisiana
EvidenceEvidence
CO2 and TemperatureGlaciersPolar Ice Arctic Antarctic Greenland
Weather SeverityBiome ChangesBiome Changes
Oceans absorb COOceans absorb CO22
CO2 in water makes Carbonic Acid
Increased CO2 especially in cold waterAs cold deep ocean currents (abyssal) resurface they are release CO2
Greater acidity of oceans is one of the factors that effect bleaching coral