Transcript Global Warming

Key concepts: Analyze the difference in the two global warming theories.
Describe the factors affecting the changes in the Earth’s climate.
Unit EQ: How does the cycle of cooling and warming in
the atmosphere affect the Earth and it’s inhabitants.
What factors cause these changes?
Atmosphere
Daily EQ: How
does the
composition of
the atmosphere
affect the
temperature of
the Earth?
Troposphere
Thermosphere
Stratosphere
Mesosphere
Exosphere
Milakovitch
Theory
Daily EQ: How
does the Earth
cool and heat
up naturally?
Greenhouse Effect
Greenhouse gases
Human Caused
Theory
Daily EQ: How
are human
actions causing
change in
atmospheric
temperatures
Ice cores
Ozone
Warm-up
• Summarize the Milankovitch theory in your
Journal
Essential Question
• How are human actions causing change in
atmospheric temperatures
Global Warming
Environmental Science
January 4, 2011
What’s been happening?
• Since the Industrial revolution human
activity has significantly changed.
– Think about it… how did the early settlers
compare to our lifestyle?
– What is different?
• CO2 concentrations have had a dramatic
increase in the last 50 years.. It is now at
the highest it has ever been.
• Methane has also been at its highest
concentration ever.
• Nitrous Oxide has had a significant spike
and is at the highest in recorded history.
How do we know this??
• We weren’t around in
20,000 B.C so how did
we get this info?
Ice cores can tell us a lot about
ancient climates, including
local temperature, CO2
concentration and, based on
dust trapped in the ice, global
and local wind patterns.
CO2 Atmospheric
Measurements
CO2 Measurements Since 1958 – Mauna Loa, Hawaii
Where do these gases come from?
• Carbon Dioxide (CO2)
– Source: Fossil fuel burning, deforestation

Anthropogenic increase: 30%

Average atmospheric residence time: 500 years

Methane (CH4)
– Source: Rice cultivation, cattle & sheep ranching, decay from
landfills, mining

Anthropogenic increase: 145%

Average atmospheric residence time: 7-10 years

Nitrous oxide (N2O)
– Source: Industry and agriculture (fertilizers)

Anthropogenic increase: 15%

Average atmospheric residence time: 140-190 years
What does this mean?
• Why should we care if there is global
warming or not?
– A group of Scientists called the
Intergovernmental Panel on Climate Change
have been trying determine what is happening
and how it will effect us.
This is what they think!
• Obviously the overall temperature is suspected
to rise by 2- 11.5 degrees C
– Not evenly though… land will be warmer then oceans.
– Higher altitude will warm more then lower altitude due
to the ice absorbing heat.
– Most of North America; all of Africa, Europe, northern
and central Asia; and most of Central and South
America are likely to warm more than the global
average
– The warming will differ by season, with winters
warming more than summers in most areas.
This is what they think!
• Higher temperatures are expected to raise
sea level by:
– expanding ocean water,
– melting mountain glaciers and small ice caps,
– causing portions of the coastal section of the
Greenland and Antarctic ice sheets to melt or
slide into the ocean.
• Increase in erratic weather events
What does sea level rise mean?
• http://geology.com/sea-levelrise/washington.shtml
Is this Human Caused?
• Climate variability is natural.
• Even in a stable climate regime, there will
always be some variation (wet/dry years,
warm/cold years) A year with completely
“average” or “normal” climate conditions is rare
• The challenge for scientists is to determine
whether any increase/decrease in precipitation,
temperature, frequency of storms, sea level, etc.
is due to climate variability or climate change.
• It is your decision…
Things we can do
• http://www.youtube.com/watch?v=42HLOx
VZAYo
Government plans
• In 1992, the Kyoto Protocol called for a 5%
reduction in carbon emissions by 2012.
The US did not sign this treaty.
Billions of Metric Tons Carbon
Goal:
Reductions in
2007
CO2 Per Year
of Metric
Billions
Carbon Tons Carbon
Gigaton
Our Goal
2007
Reductions
in CO2
Per Year
Produce electricity
efficiently
Use electricity
efficiently
Vehicle efficiency
Solar and Wind
Power
Biofuels
Carbon capture
and storage
What’s the proof that
global warming is
taking place?
Global Warming facts
• The ice cap on Mount
Kilimanjaro may be
gone in 20 years. About
1/3 of Kilimanjaro’s ice
field has disappeared in
the last 12 years and
82% of it has vanished
since it was first
mapped in 1912.
Global Warming Facts
• Sea ice in the Arctic
Ocean is thinning.
• Many animals depend on
these areas for food and
shelter.
Global Warming Facts
• Mass extinction of animals
Select one of the RAFTs below and
write a 500 word article
R= Arctic Ice
A= Humans
F= Plea Bargain
T= Melting
must stop
R= Co2
A= Polar Bears
F= Threat
T= I am coming for
you
R= Earth
A= Solar System
F= Help Wanted
T= In need of new
home
Key for letters above!
Role of the Writer: Who are you as the writer?
Audience: To whom are you writing? A senator? Yourself?
Format: In what format are you writing? A diary entry? A newspaper?
Topic: What are you writing about?