Transcript Climate Change Part I

TEAMS
5)
4)
6)
Era
1)
Era
2)
3)
Global temperature anomalies: 2008 to 2012
CHAPTER 14
CLIMATE CHANGE
Part 1
Introduction, definitions, and summary
Learning Objectives
(1) I can recall key features of circulation
in the atmosphere and oceans
(2) I can describe the greenhouse effect and
its role in climate change
(3) I can explain the global carbon cycle
(4) I can describe predictions of global
climate models (GCMs)
Copyright © 2014 John Wiley & Sons, Inc. All rights reserved.
Weather: short-term state of the
atmosphere at a given location
Climate: Long-term (~30 years) average
weather pattern in a particular region
resulting from interactions among land,
ocean, atmosphere, ice, and the biosphere
Global Climate Change: Any largescale change in climate over time, whether
natural or as a result of human activity
Global Warming: Increase in the average
temperature of Earth’s surface (including
the oceans)
2008-2012 Global temperature
anomalies, deviation from average
CHAPTER 14
CLIMATE CHANGE
Among scientists, there is no
controversy about the cause or
existence of climate change.
95% of 3152 climate scientists agree
that “human activity is a significant
contributing factor in changing mean
global temperatures“
This is about as well accepted as the
theory of plate tectonics.
© 2013 John Wiley & Sons, Inc. All rights reserved.
Yet still, the existence of climate
change and the human role in it is
debated in some parts of the country
and in congress. Why?
Copyright © 2014 John Wiley & Sons, Inc. All rights reserved.
• CHAPTER 14
CLIMATE CHANGE
Among scientists, there is no
controversy about the cause or
existence of climate change.
95% of 3152 climate scientists agree
that “human activity is a significant
contributing factor in changing mean
global temperatures“
This is about as well accepted as the
theory of plate tectonics.
© 2013 John Wiley & Sons, Inc. All rights reserved.
Yet still, the existence of climate
change and the human role in it is
debated in some parts of the country
and in congress. Why?
CHAPTER 14
CLIMATE CHANGE
Copyright © 2014 John Wiley & Sons, Inc. All rights reserved.
•
Atmospheric CO2 is growing by 2.1 ppm
per year and is accelerating.
•
It reached 400 ppm (see 350.org) in 2013,
not seen since 15 million year ago (gulp..
back then sealevel was 23-36 m higher,
and global temperature was 2.8°-5.5°C
warmer).
•
During the past 30 years, Earth’s surface
temperature has trended upward about
0.2°C per decade.
•
The International Panel of Climate
Change (IPCC) recognizes scientific
predictions that the world could be
1.5-2°C by the end of this century.
Global temperature anomalies: 2008 to 2012
CHAPTER 14
CLIMATE CHANGE
2°C? So what?
At an increase of 2°C global
average temperature, many
climatologists believe that large
portions of Earth’s surface will
become uninhabitable due to:
• Drought
• Extreme and dangerous weather
patterns
• Flooding due to unstoppable sea
level rise
• Scarcity of food, freshwater
• Heat waves
Copyright © 2014 John Wiley & Sons, Inc. All rights reserved.
Global temperature anomalies: 2008 to 2012
CHAPTER 14
CLIMATE CHANGE
Part 1
Introduction, definitions, and summary
Learning Objectives
(1) I can recall key features of circulation
in the atmosphere and oceans
(2) I can describe the greenhouse effect and
its role in climate change
(3) I can explain the global carbon cycle
(4) I can describe predictions of global
climate models (GCMs)
Copyright © 2014 John Wiley & Sons, Inc. All rights reserved.
Layers and temperatures of
the atmosphere
Learning Objective 1: I can recall key features
of circulation in the atmosphere and oceans
Question: Increasing CO2 in the
troposphere has caused it to trap more
heat (0.2°C per decade). Less heat is
therefore transported out of the
troposphere upward, and this has
caused the upper layers of the
atmosphere to
A) cool at a rate of 0.05°C per decade
B) heat at a rate of 0.05°C per decade
C) have remained unchanged
Ozone (O3) blocks 95% Sun’s
ultraviolet rays. Cluorofluorocarbons
Airplanes
(CFC’s) produced by aerosols destroy ozone &
create risk to people (skin cancer), animals, &
plants.
We live in the troposphere
General Circulation
in the Troposphere
Learning Objective 1: I can recall key features
of circulation in the atmosphere and oceans
Question: What causes the trade wind
flow from north(east) to the
south(west) in the northern
hemisphere?
A) Circulation in the Ferrel cell
B) Circulation in the Polar cell
C) Warm air rising near the equator
and cool air sinking near the
subtropical zone (30oN)
D) The Hadley cell in the southern
hemisphere
Copyright © 2014 John Wiley & Sons, Inc. All rights reserved.
Learning Objective 1: I can recall key features of circulation in the atmosphere and oceans
Troposphere Circulation explains
general locations of major climate zones
Question: Why is the equatorial zone wet?
A) Clouds are swept south with the trade winds to
(with variability due to local topography, ocean
the equator
circulation, wind patterns, continental shapes) B) Warm air can hold more water vapor; as warm
air rises near the equator, it cools and water
vapor condenses
C) Cool air holds more water vapor; as the cool air
above the equator rises, it warms and water
Polar (dry)
vapor condenses
D) None of the above
Subpolar (wet)
Subtropical (dry)
Equatorial (wet)
Subtropical (dry)
Learning Objective 1: I can recall key features of circulation in the atmosphere and oceans
Troposphere Circulation explains
general locations of major climate zones
Question: Why are the dry deserts in the subtropical zone below the sinking air of the Hadley
(with variability due to local topography, ocean Cell?
circulation, wind patterns, continental shapes) A) Clouds are swept away from the subtropics with
the trade winds to the equator
B) The air sinking is dry air that lost most of its
water vapor near the equator
C) The water in the sinking air condenses so when
Polar (dry)
it sinks to the ground its dry.
D) None of the above
Subpolar (wet)
Subtropical (dry)
Equatorial (wet)
Subtropical (dry)
Learning Objective 1: I can recall key features of circulation in the atmosphere and oceans
Question: Ocean circulation is partly driven by the sinking
of surface water to the seafloor in the North Atlantic.
Why does the North Atlantic surface water sink?
Thermohaline circulation of the ocean
carries heat around the globe and affects
A) It was warm and therefore has a lot of dissolved salt, but
climate.
now it is cool. Cool salty water is dense and sinks.
B) The cool salty water at the bottom of the North Atlantic is
drawn south by the Coriolis force.
C) High winds in the north Atlantic push the water down
D) The surface water is pushed under the polar icecap so it
sinks to the bottom of the ocean.
Global temperature anomalies: 2008 to 2012
CHAPTER 14
CLIMATE CHANGE
Part 1
Introduction, definitions, and summary
Learning Objectives
(1) I can recall key features of circulation
in the atmosphere and oceans
(2) I can describe the greenhouse effect and
its role in climate change
(3) I can explain the global carbon cycle
(4) I can describe predictions of global
climate models (GCMs)
Copyright © 2014 John Wiley & Sons, Inc. All rights reserved.
Learning Objective 2: I can describe the greenhouse effect and its role in climate change
Greenhouse effect: ability of the atmosphere to store heat
that is radiated upward from Earth so it cannot escape into
space.
• It maintains the average temperature conducive to life
at about 14°C (57.2°F). (Venus’s greenhouse keeps it
at 477°C)
• Without it, Earth’s average temperature would be –
18°C.
• It is central to Earth's heat budget.
Copyright © 2014 John Wiley & Sons, Inc. All rights reserved.
Learning Objective 2: I can describe the greenhouse effect and
its role in climate change
6 Greenhouse Gases
Global warming
potential (GWP)
270 x CO2
8% increase
(fossil fuels,
fertilizers, solid waste,
industrial production
of nylon & nitrous acid)
Fluorocarbons (industrial processes)
(burning fossil
fuels,
deforestation,
sewage,
Global warming
livestock,
potential (GWP)
cultivating rice)
21 x CO
GWP
30,000 x CO2
2
Signing of Montreal protocol by 27 nations
To stop CFC production
60% increase
Partly
counteracted by
Aerosols: fine
particles released
by
pollution or
volcanic eruptions
raise the
atmosphere’s
albedo, and reflect
solar heat.
(burning fossil fuels,
deforestation)
21% increase
1. Carbon dioxide (CO2)
2. Methane (CH4)
3. Nitrous oxide (N2O)
4. Ozone (O3)
5. Fluorocarbons
including CFC’s
6. Water vapor (H2O)
20% increase
make up 1% of the atmosphere, and absorb infrared radiation (i.e., heat) so the Earth warms:
Learning Objective 2: I can describe the greenhouse effect and
its role in climate change
6 Greenhouse Gases
Question: Why does water vapor cause a positive feedback
for global warming?
C) More H2O vapor means more clouds, more
clouds
2
reflects more sunlight, and this re-enforces global
warming
Fluorocarbons (industrial processes)
21% increase
(burning fossil
A) Warm air holds more H2O vapor, more H2O traps more
fuels,
heat, air gets warmer
deforestation,
sewage,
B) Cooler air holds more H2O vapor,
morewarming
H2O traps more
Global
livestock,
heat, air gets warmer
potential (GWP)
cultivating rice)
21 x CO
Global warming
potential (GWP)
270 x CO2
8% increase
(burning fossil fuels,
deforestation)
(fossil fuels,
fertilizers, solid waste,
industrial production
of nylon & nitrous acid)
GWP
30,000 x CO2
Signing of Montreal protocol by 27 nations
To stop CFC production
60% increase
1. Carbon dioxide (CO2)
2. Methane (CH4)
3. Nitrous oxide (N2O)
4. Ozone (O3)
5. Fluorocarbons
including CFC’s
6. Water vapor (H2O)
20% increase
make up 1% of the atmosphere, and absorb infrared radiation (i.e., heat) so the Earth warms:
Earth’s Heat
Budget
Learning Objective 2: I can describe the greenhouse effect and
its role in climate change
340 watts/m2
~340 watts/m2
Heat balance means energy entering the atmosphere= energy leaving it
Team Hadean Currently, the heat that escapes the insulating effects of
greenhouse gases is 130 Watts/m2. Higher concentrations of greenhouse gases in
the future would cause that amount of escaping heat to:
(A) increase, (B) decrease,Copyright
(C) not
change
© 2014 John Wiley & Sons, Inc. All rights reserved.
Earth’s Heat
Budget
Learning Objective 2: I can describe the greenhouse effect and
its role in climate change
340 watts/m2
~340 watts/m2
Heat balance means energy entering the atmosphere= energy leaving it
Team Question If more greenhouse causes the amount of heat escaping them to decrease
below 130 Watts/m2. How will that change the Earth’s heat balance?
6 Greenhouse Gases
Learning Objective 2: I can describe the greenhouse effect and
its role in climate change
1. Carbon dioxide (CO2)
2. Methane (CH4)
3. Nitrous oxide (N2O)
4. Ozone (O3)
5. Fluorocarbons
including CFC’s
6. Water vapor (H2O)
(burning fossil fuels,
deforestation)
Question What has been the rate (or
slope) of CO2 increase over the past 32
years?
(A) 50 ppm/yr
(B) 32 ppm/yr
(C) 32/50=0.65 ppm/yr
(D) 50/32=1.6 ppm/yr
Run = 32 years
Rise =50 ppm
make up 1% of the atmosphere, and absorb infrared radiation (i.e., heat) so the Earth warms:
People begin having headaches when CO2
levels reach about 0.5% (5000 ppm) and
lose consciousness when levels reach 10%
(100,000 ppm).
Question: If the rate of CO2 remains the
same as it has the past 32 years, will
people still be able to breath in 100 years?
A) yes
B) no
C) I can’t tell, but I hope so!
Global temperature anomalies: 2008 to 2012
CHAPTER 14
CLIMATE CHANGE
Part 1
Introduction, definitions, and summary
Learning Objectives
(1) I can recall key features of circulation
in the atmosphere and oceans
(2) I can describe the greenhouse effect and
its role in climate change
(3) I can explain the global carbon cycle
(4) I can describe predictions of global
climate models (GCMs)
Copyright © 2014 John Wiley & Sons, Inc. All rights reserved.
Learning Objective 3: I can explain the global carbon cycle
LONG TERM GEOLOGIC CARBON CYCLE
CO2 is removed from the atmosphere and oceans by:
• Chemical weathering if silicate rocks via hydrolysis removes CO2 from atmosphere and moves it
to the oceans
• Calcification in plankton removes CO2 from oceans and puts it on the seafloor where it turns to
limestone or fossil fuels where it is stored in the Earth
CO2 is added to atmosphere and oceans by:
• Volcanic outgassing or tectonic exposure of
fossil fuels moves CO2
out of the Earth to the atmosphere
Team Archean:
What geologic process(es)
removes CO2 from the
atmosphere?
What geologic process adds
CO2 back into the
atmosphere?
Learning Objective 3: I can explain the global carbon cycle
ANNUAL CARBON CYCLE
Learning Objective 3: I can explain the global carbon cycle
INTERMEDIATE-TERM OR NEAR-SURFACE CARBON CYCLE
Team Proterozoic: Where is most
of the CO2 stored that is accessible
on the intermediate-term?
GtC/yr
GtC/yr
GtC/yr
GtC/yr
GtC/yr
GtC
GtC
GtC
Learning Objective 3: I can explain the global carbon cycle
INTERMEDIATE-TERM OR NEAR-SURFACE CARBON CYCLE
Team Paleozoic: Where is the CO2 that is
entering the atmosphere coming from and at
what rate?
GtC/yr
GtC/yr
GtC/yr
GtC/yr
GtC/yr
GtC
GtC
GtC
The Natural Changes in Global Climate: Learning Objective 3: I can explain the
changes in Earth-Sun orbital geometry and global carbon cycle
tilt of Earth led to fluctuations in short-term
CO2 cycle and global climate
Climate Records from Ice Cores
The Natural Changes in Global Climate: Learning Objective 3: I can explain the
changes in Earth-Sun orbital geometry and global carbon cycle
tilt of Earth led to fluctuations in short-term
CO2 cycle and global climate
Climate Records from Ice Cores +
Recent Atmospheric Measurements
We are imposing an excursion of CO2 unlike any other in the geologic record
Fill in the blanks using “greenhouse effect” or “global warming”
When the
is increased, then that leads to
If greenhouse gases are increasing, then
.
will occur.
Team Mesozoic You have a friend who says, “This greenhouse effect thing is bad for
Earth. We should take all carbon dioxide out of our atmosphere as fast as we can!”
Explain how your friend is misunderstanding the idea of Earth’s greenhouse effect.
Global temperature anomalies: 2008 to 2012
CHAPTER 14
CLIMATE CHANGE
Part 1
Introduction, definitions, and summary
Learning Objectives
(1) I can recall key features of circulation
in the atmosphere and oceans
(2) I can describe the greenhouse effect and
its role in climate change
(3) I can explain the global carbon cycle
(4) I can describe predictions of global
climate models (GCMs)
Copyright © 2014 John Wiley & Sons, Inc. All rights reserved.
Learning Objective 4: I can explain predictions of global climate models
GCM’s use state-ofthe art
supercomputers
(100’s to 10,000’s of
cores) to test the
impact of elevated
CO2 on climate.
Included in climate models:
• Energy balance
• Ocean Circulation
• Atmospheric Physics
• Ice Sheets
• Glaciers
• Vegetation
• Clouds
• Feedback/impacts of
human activities
Learning Objective 4: I can explain predictions of global climate models
GCM’s use state-ofthe art
supercomputers
(100’s to 10,000’s of
cores) to test the
impact of elevated
CO2 on climate.
Technical challenge is
to simulate local
feedbacks and weather
conditions
Learning Objective 4: I can explain predictions of global climate models
Question: Which types of GCMs best
predicted the change in temperatures
since 1910?
A) Models using only natural forcings
B) Models using both natural and
anthropogenic forcings
C) Both types of models poorly
matched observations
D) Both types of models match the
observations equally well.
Temperature anomaly, or deviation from the average
Learning Objective 4: I can explain predictions of global climate models
Why is it important for the
GCMs to produce the
green curve in this
diagram?
Team Cenozoic
-At present-day is the temperature higher or lower than normal (average)?
-What do the GCMs predict about the relationship between the level of greenhouse
gas emissions (low vs high) and global temperature in the future?
-By 2050, 34 yrs from now, how much warmer might the average temperature be than
it is today?