Transcript Intergovernmental Panel on Climate Change

Chapter 21
Global Climate Change
Climate Change Terminology
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Greenhouse Gas
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Positive Feedback
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Change in some condition triggers a response that
intensifies the changed condition
Infrared Radiation
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Gas that absorbs infrared radiation
Radiation that has a wavelength that is longer than that
of visible light, but shorter than that of radio waves
Greenhouse Effect
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Increase of heat in a system where energy enters
(often as light), is absorbed as heat, and released
sometime later
Introduction to Climate Change
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"Scientific evidence for warming of the
climate system is unequivocal." -
Intergovernmental Panel on Climate
Change
Evidence of Climate Change
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Spring in N. hemisphere now begins 6 days
earlier
Evidence of Climate Change
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Sea level rise
Evidence of Climate Change
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Global temperature
rise
Evidence of Climate Change
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Warming oceans
Evidence of Climate Change
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Shrinking ice sheets
The Greenland and Antarctic
ice sheets have decreased in
mass. Data from NASA show
Greenland lost 150 - 250
km3/year between 20022006, while Antarctica lost
about 152 km3 of ice
between 2002-2005.
Flowing meltwater from the Greenland ice sheet
Evidence of Climate Change
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Declining Arctic sea ice
Both the extent and thickness of Arctic sea
ice has declined rapidly over the last
several decades. 9
Evidence of Climate Change
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Glacial retreat
Glaciers are
retreating almost
everywhere around
the world —
including in the Alps,
Himalayas, Andes,
Rockies, Alaska and
Africa.10
Evidence of Climate Change
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Extreme events
The number of record high temperature
events in the United States has been
increasing, while the number of record low
temperature events has been decreasing,
since 1950. The U.S. has also witnessed
increasing numbers of intense rainfall
events.11
Evidence of Climate Change
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Ocean acidification
The carbon dioxide content of the Earth’s
oceans has been increasing since 1750,
and is currently increasing about 2 billion
tons/year. This has increased ocean
acidity by about 30%. 12
Introduction to Climate Change:
Mean Annual Global
Temperature 1960–2007
Causes of Climate Change
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Greenhouse gas concentrations increasing
Causes of Climate Change
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Increased
concentration of CO2
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Burning fossil fuels in
cars, industry and
homes
Deforestation
Burning of forests
Greenhouse Effect
Pollutants That Cool the
Atmosphere
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Atmospheric Aerosols
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Both human and natural sources
Tiny particles that remain in troposphere for
weeks or months
Often contain sulfur
Complicates models of climate change
Climate Models
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Climate affected by:
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winds, clouds, ocean currents, and albedo
Advanced models can project future
warming events
Models have limitations
Effects of Global Climate Change
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Wildfire in California
Effects of Global Climate Change:
1. Melting Ice and Rising Sea Levels
Sea level rise caused in 2 ways
1.
2.
Thermal Expansion
Melting of land ice
Melting has positive feedback
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Increased melting decreases ice, which
decreases albedo leading to further warming
Melting Ice and Rising Sea Levels
1957
1998
Glacier National Park
Impacts in Fragile Areas
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Eskimo Inuit
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Climate change is altering their existence
Wildlife displaced
Reduced snow cover and shorter river ice
seasons
Thawing of permafrost (right)
Tuvalu- threatened by permanent flooding
on their island
Effects of Global Climate Change:
2. Changing Precipitation Patterns
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Some areas will get more water, some
areas will have greater droughts
Effects of Global Climate Change:
3. Effects on Organisms
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Zooplankton in parts of CA have
decreased by 80% since 1951
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Effecting entire food chain
Decline in krill around Antarctica
Species have shifted their geographic
range
Migrating birds are returning to summer
homes earlier
Effects on Organisms: Coral Reefs
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Coral reefs can be bleached (right) due to
increase in water temperature
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Affects coral symbiotes and makes them more
susceptible to diseases
Effect on Organisms: Vegetation
4. Effects on Human Health
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Increased number of heat-related illnesses
and deaths
5. Effects on Agriculture
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Difficult to anticipate
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Productivity will increase in some areas and decrease
in others
Rise in sea level will inundate farmland
Effect on pests is unknown
Warmer temperatures will decrease soil moisturerequiring more irrigation
Location where certain crops can be grown may
change
International Implications of
Climate Change
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Developed vs.
Developing
countries
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Differing selfinterests
Differing ability
to meet the
challenges of
climate change
Dealing with Global Climate
Change
Two ways to manage climate change
1.
Mitigation: Limiting greenhouse gas
emissions to moderate global climate
change
2.
Adaptation: Learning to live with
environmental changes and societal
consequences brought about by global
climate change
Relationship Between Mitigation
and Adaptation
Dealing with Global Climate
Change: Mitigation
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Locate/invent alternative fuels to fossil
fuels
Increase efficiency of cars and trucks
Carbon Capture and Storage
Plant and Maintain trees to naturally
sequester carbon
Dealing with Global Climate
Change: Adaptation
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Rising sea levels and coastal populations
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Move inland
Construct dikes and levees
Adapt to shifting agricultural zones
NYC sewer line
International Efforts to Reduce
Greenhouse Gas Emission
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Kyoto Protocol
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Legally binding
Provides rules on reducing greenhouse gases
US and Australia have not sign it - it will be
difficult to implement without US backing
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Chapter 21: Global Climate Change Climate Crisis Network
http://www.climatecrisis.net/takeaction/
Goddard Institute for Space Studies: Surface Temperature
Analysis
http://data.giss.nasa.gov/gistemp/
United Nations Intergovernmental Panel on Climate Change
http://www.ipcc.ch/
US Global Change Research Program
http://www.globalchange.gov/
Pew Center on Global Climate Change
http://www.pewclimate.org/
World View of Global Warming - The Photographic
Documentation of Climate Change
http://www.worldviewofglobalwarming.org/pages/glaciers.html