Climate Change Notes
E2.3A
Explain how carbon exists in different forms such as limestone (rock), carbon
dioxide (gas), carbonic acid (water), and animals (life) with Earth systems
and how those forms can be beneficial or harmful to humans.
E2.2D
Identify the main sources of energy to the climate system.
E4.p2B
Describe the difference between weather and climate. (prerequisite)
E5.4A
Explain the natural mechanism of the Greenhouse effect including
comparisons of the major greenhouse gases (water vapor, carbon dioxide,
methane, nitrous oxide, and ozone).
Chapter 14.4; Chapter 27.3;
Pgs. 375-377
Pg. 782 (compares atmosphere on Earth with atmosphere on Mars and Venus)
The Greenhouse Effect- the heating process where gases in the atmosphere trap heat from the
sun to continually warm the earth
- About 70 percent of the sun’s energy that reaches the outer atmosphere enters (other 30
percent reflected by outer atmosphere)
- 50 percent reaches the surface
- 20 percent is absorbed by the atmosphere on its way in
- Solar radiation strikes the earth’s surface, then gets re-radiated back into the
atmosphere.
- Gases like water vapor (H2O) and carbon dioxide (CO2) absorb this energy and then
radiate it back to the earth’s surface
- Without it, life (as we know it) would not exist on earth.
EX: Sitting in your car with the windows rolled up on a hot, sunny day. Hotter inside the car than
outside.
Greenhouse Gases- atmospheric gases that absorb solar energy and trap heat to warm the earth.
They allow solar radiation to come in but not get out.
Water Vapor (H2O)- accounts for most of the greenhouse effect
Carbon Dioxide (CO2)- produced naturally from volcanic eruptions, and also by
humans; has increased by 30 percent since Industrial Revolution
Methane (CH4)- principal component of natural gas; produced by bacteria and given off
from cattle gas (burping); also put into atmosphere by the melting of permafrost at the
poles
Nitrous Oxide (N2O)- laughing gas; also used as a propellant; produced by bacteria in
soils and the oceans; attacks the ozone (helps regulate the amount)
Ozone (O3)- produced when UV rays react with atmospheric oxygen;
* SIDE NOTES
- Venus is very HOT because atmosphere contains 95 percent CO2
- Burning ONE molecule of Methane (natural gas) in the presence of oxygen produces
ONE molecule of CO2 and 2 molecules of water vapor (H2O)- BOTH are greenhouse
gases.
- Fossil fuels: coal, oil, gasoline
Anthropogenic (Human) Affects
CO2- Burning fossil fuels (gasoline and oil) in cars and industry; deforestation (cutting
down trees); respiration (breathing)
CH4- Increased livestock; landfill emissions; septic emissions; gas pipeline emissions
N2O- Increased use of fertilizers that release nitrous oxides
CFCs- used in refrigeration systems and fire suppressants
It’s a vicious cycle. As temperatures increase, relative humidity increases (warm air has capacity
to hold more water) and more water vapor in the air means higher temperatures due to the
greenhouse effect.
Global Warming- a rise in average global temperatures
- Gases that trap heat are called greenhouse gases
- Recently, there has been an increase in the amount of CO2 gases, due to human activity,
burning fossil fuels (factories, automobiles, etc.)
- With an increase in greenhouse gases, more heat energy is being trapped inside the earth, and
global temperatures continue to rise.
- By 2010, yearly average temperatures could rise about 6 F.
Radiation Balance and What’s Being Done
http://asd-www.larc.nasa.gov/SCOOL/budget.gif
- For life to continue to exist on earth, the amount of heat energy (radiation) must be in balance.
If CO2 levels continue rise, too much heat would be trapped, which could severely affect plant
and animal life and habitat.
- Many countries have signed agreements to reduce the amount of CO2 that is being produced in
their countries.
E5.4B
Describe natural mechanisms that could result in significant changes in
climate (e.g. major volcanic eruptions, changes in sunlight received by the
earth, and meteorite impacts).
Pgs. 372-374
Volcanic Eruptions
Emit CO2 (& water vapor) into the atmosphere, which is a heat-trapping greenhouse gas.
Emit sulfuric gases, which turn into sulfuric aerosols. These aerosols absorb or trap
terrestrial (earth) radiation and heat the earth.
These sulfuric gases also combine with water to form acid rain which increases
the weathering of limestone and puts more carbon dioxide into the air.
Emit gases that react with CFCs and reduce the ozone levels
The HAZE EFFECT- when gases and dust (mainly from volcanic eruptions) prevent
solar radiation from reaching the earth and global temperature temporarily COOLS.
Solar Radiation
The stronger the intensity of solar radiation (more sunspots), the warmer the earth’s
atmosphere will be.
The weaker the intensity of solar radiation (less sunspots), the cooler the earth’s
atmosphere will be.
Axial Tilt and Orbital Change (Milankovitch Cycles)
As earth’s axial tilt increases (higher angle), temperature range increases.
As earth’s axial tilt decreases (lower angle), temperature range decreases.
Changes every 40,000 years (between 21.5 and 24.5 degree tilt)
As earth orbits closer to (narrower/elliptical orbit) the sun, temperature increases.
As earth orbits further away from (wider/circular orbit) the sun, temperature
decreases.
Known as eccentricity
Changes every 100,000 years
When earth “wobbles” (for 26,000 years), like a top that is slowing down, it gets
closer to and further away from the Sun.
Known as precession
Meteorite Impacts
Meteorite- space object that collides with the Earth and survives impact.
Dust from these collisions causes a haze effect which can affect climate
Haze temporarily cools the climate
(Can later warm climate as more heat is trapped)
Dust provides more condensation nuclei (the beginning of clouds), which lead to
more rain
E5.4C
Analyze the empirical relationship between the emissions of carbon dioxide,
atmospheric carbon dioxide levels and the average global temperature over
the past 150 years.
Carbon Dioxide Emissions
Since 1750, carbon dioxide emissions have increased by 87 ppm (31% increase)
315 billion tons of carbon has been released
Nearly half of it has been released in the last 35 years (since 1970)
2003-2004, there was a 5.4 percent increase in used carbon
BOTTOM LINE: Humans are putting more and more carbon dioxide into the atmosphere
Atmospheric Carbon Dioxide Levels
Before the start of the Industrial Revolution (1800s), atmospheric CO2 was at 280 ppm (parts per
million). In the last 233 years, it has increased to 380 ppm.
First 200 years, it increased from 280 to 330 ppm.
In the last 33 years, it has increased from 330 to 380 ppm.
Average Global Temperature
Over the past 150 years average global temperature has risen anywhere from 0.5° to 1.5° C
E5.4D
Based on evidence of observable changes in recent history and climate
change models, explain the consequences of warmer oceans (including the
results of increased evaporation, shoreline and estuarine impacts, oceanic
algae growth, and coral bleaching) and changing climatic zones (including
the adaptive capacity of the atmosphere).
Consequences of Warmer Oceans
Increased evaporation and shoreline impacts
Increased evaporation leads to more rain (stronger hurricanes)
Can raise sea-levels (in conjunction with the melting of the polar ice caps)
Floods will occur
Shoreline environments are disrupted and certain organisms cannot adapt
Highly populated coastal areas are at greater risk of damage and destruction
Increased evaporation will also lead to higher salinity of ocean water
Estuarine Impacts and algae growth
Estuary- place where river meets the sea/ocean.
Warmer ocean water heats the atmosphere above and more rain can produce more runoff. More
runoff can add phosphates and nitrates to the ocean, which can cause an immense growth of
algae. This prevents other aquatic life from inhabiting that area of water.
Less runoff would decrease flushing, and allow predators and pathogens to penetrate the
estuarine zone.
Coral Bleaching
Coral Reefs play a major role in the economies of Florida and Hawaii.
Fisheries, recreation, tourism, coastal protection
In the last 100 years, there has been a major decline in the health of coral reefs
With warmer ocean temperatures, coral skeletons get weaker, they expel the algae they depend
on to survive (get white, known as coral bleaching), and they do not grow as much. As these
coral die, surrounding areas could lose millions to billions of dollars a year in economic dollars.
Certain areas of the world receive more or less heat and more or less precipitation, which has a
domino affect on the local ecosystem.
E5.4e
Based on evidence from historical climate research (e.g. fossils, varves, ice
core data) and climate change models, explain how the current melting of
polar ice caps can impact the climactic system.
Polar ice caps reflect incoming solar radiation back into space due to their high albedo (ability to
reflect light). Through this process, the global climate is kept cooler because the solar radiation
is reflected versus being absorbed. With the increasing global temperatures, polar ice caps have
begun melting which has allowed for more solar radiation to be absorbed. Hadley Scientists
predict that sea level will rise 8 to 12 inches by the year 2100. Liquid water absorbs the Sun's
energy rather than reflecting it into the atmosphere the way ice does. As the oceans warm and ice
thins, more solar energy is absorbed by the water, creating positive feedbacks that lead to further
melting. Such dynamics can change the temperature of ocean layers and impact ocean circulation
by decreasing salinity (and therefore density). This disrupts the thermohaline current and effects
the distribution of heat. This can alter regional climate and change marine habitats.
Thermohaline circulation would weaken and slow down and temperatures (especially in
the North Atlantic) would become cooler. Evidence from sedimentary rocks has shown
that the last time it shut down was about 12,700 years ago during the Younger Dryas
Event (ice age), causing temperatures to cool about 5 degrees on average.
Scientists study the ratio of oxygen-16 and oxygen-18 in the calcium carbonate of fossils and
how they vary in accordance to water temperature in order to study past climates.
Data from ice core samples strongly suggests a relationship between rising atmospheric carbon
dioxide levels and rising temperature.
E5.4f
Describe the geologic evidence that implies climates were significantly colder
at times in the geologic record (e.g. geomorphology, striations, and fossils).
Geomorphology- study of the form and structure of the earth.
Scientific evidence exists that proves climatic conditions on the Earth were once much cooler.
Glacial evidence is found in many locations on the Earth that now have very warm or temperate
climates (like Africa). These pieces of evidence are:
striations which indicate glacial movement over rocks (where they normally wouldn’t
exist today)
South Africa, India, South America- Has ancient glacial “scars”. Too warm of a
climate to have glaciers today
moraines that mark climate stability (glacial movement ceasing temporarily and then
retreating)
glacial erratics which show glacial boulders being transported long distances from their
place of origin
Another piece of geologic evidence is fossils found in locations where that organism couldn’t
possibly exist indicating a different climate in the past. Because certain types of plants grow in
particular climates, the discovery of plant fossils in areas that presently don’t support that type of
plant provide evidence that a different (in this case, cooler) climate once existed there.
EX: Wegener’s evidence for his theory of continental drift
Spitsbergen- Norwegian Island has tropical plant fossils. Too cold of a climate
today to have plant life.
E5.4g
Compare and contrast the heat-trapping mechanisms of the major
greenhouse gases resulting from emissions (carbon dioxide, methane, nitrous
oxide, and fluorocarbons) as well as their abundance and heat-trapping
capacity.
Natural Emissions
Water Vapor- volcanic eruptions; evaporation of water;
Most common/abundant greenhouse gas in the atmosphere (accounts for 60 to 70 percent of all
greenhouse gases)
As human activities produce more greenhouse gases in the atmosphere and temperature
increases, so does the rate of evaporation, which will put more water vapor into the
atmosphere.
Artificial Emissions
Carbon Dioxide- volcanic eruptions; decay of organic material; burning of fossil fuels (coal, oil,
gasoline); burning of wood products; burning of waste; deforestation (release carbon into
atmosphere and reduces the amount of atmospheric carbon dioxide that can be absorbed).
We are releasing carbon dioxide faster than it can be absorbed and this is a problem.
Scientists have analyzed air bubbles trapped in glaciers to compare atmospheric carbon dioxide
from long ago to today’s current levels. The amount has increased by about 35 percent since
1750. Scientists predict CO2 levels will double or triple in the next 100 years if current trends
don’t cease. CO2 can stay in the atmosphere for centuries.
Methane- animal gas from digestion; decomposition of wastes (landfills); microorganisms
breaking down organic matter (especially in damp soils like rice fields)
Methane is 30 times more efficient at trapping heat than carbon dioxide
Methane only stays in the atmosphere for about a century
Atmospheric Methane has doubled since 1750
Nitrous Oxide- burning of fossils fuels and automobile exhaust; nitrogen fertilizers that release
NO2 when breaking down the soil
NO2 is 300 times more efficient at trapping heat than carbon dioxide
NO2 stays in atmosphere for a century
Atmospheric NO2 has increased by about 18 percent since 1750
Ozone- both naturally produced and artificially produced
A component of smog- limited to industrialized regions
Fluorocarbons (CFCs and HCFCs)- used in manufacturing processes;
GREATEST heat-trapping capacity
Several thousand times more efficient at trapping heat than carbon dioxide
CFCs- aerosols, refrigerants
Release chlorine into the upper atmosphere, which would destroy the protective
ozone
Ban on CFCs in developed countries, except for asthma inhalers
Switched to use of HCFCs, but they still release chlorine into atmosphere.
By 2030, these will no longer be used
HFCs and PFCs do not destroy ozone, but are still powerful greenhouse gases
Links
Paleoclimate (climate from the past)
http://www.ncdc.noaa.gov/paleo/
Carbon Cycle (E2.3A)
Carbon Cycle Animation
http://bcs.whfreeman.com/thelifewire/content/chp58/5802002.html
Main sources of energy to the Climate System (E2.2D)
http://www.solcomhouse.com/climatechange.htm
E4.5A
Power Point on Climate Change
http://www.earth4567.com
Info
http://www.epa.gov/climatechange/
http://www.ecobridge.org/content/g_cse.htm
http://www.esd.ornl.gov/projects/qen/transit.html
Greenhouse Effect and Global Warming Animations
http://www.epa.gov/climatechange/kids/global_warming_version2.html
http://science.nationalgeographic.com/science/environment/global-warming/gw-overview-interactive.html
http://encarta.msn.com/media_701765046_761578504_-1_1/Greenhouse_Effect.html
http://www.bbc.co.uk/climate/evidence/greenhouse_effect_img.shtml
GREAT Greenhouse Effect/Global Warming Simulation
http://phet.colorado.edu/new/simulations/sims.php?sim=The_Greenhouse_Effect
Global Warming Article (Time)
http://www.time.com/time/magazine/article/0,9171,1176980,00.html
Greenhouse Gases and Greenhouse Effect
http://en.wikipedia.org/wiki/Greenhouse_gas
Greenhouse Gases and Society
http://www.umich.edu/~gs265/society/greenhouse.htm
EPA on Greenhouse Gas Emissions
http://yosemite.epa.gov/oar/globalwarming.nsf/content/emissions.html
Greenhouse Effect Computer Lab Activity and Graphing Assignment
http://teachertech.rice.edu/Participants/sboone/Lessons/Greenhouse/
Effects of Global Warming Info
http://www.effectofglobalwarming.com/
E5.4B
Volcanic Effects on Climate
http://volcano.und.nodak.edu/vwdocs/frequent_questions/top_101/oldEffects.html
http://www.cotf.edu/ete/modules/volcanoes/vclimate.html
Explanation of Volcanic Haze Effect on Cooling Temperatures
http://www.geology.sdsu.edu/how_volcanoes_work/climate_effects.html
Info and Graph on Correlation Between Number of Sunspots and Temperature
http://www.oar.noaa.gov/spotlite/archive/spot_sunclimate.html
http://stars5.netfirms.com/suncli.htm
Graph on Annual Number of Sunspots since 1700
http://www.ocs.orst.edu/ats210/sunspots.gif
Image of Difference in Eccentricity
http://www.geol.umd.edu/~jmerck/geol100/images/37/eccentricity.gif
E5.4c
CO2 emissions info and data
http://cdiac.ornl.gov/trends/emis/meth_reg.htm
CO2 emissions graphs
http://www.eia.doe.gov/oiaf/archive/ieo01/images/figure_94.jpg
http://www.guardian.co.uk/globalwarming/graphic/0,,397009,00.html
Atmospheric CO2 concentration graphs
http://www.omgfilms.com/spark1/images/stories/fruit/mauna_loa_carbon_dioxide.png
http://www.aip.org/history/climate/images/maunaloa.jpg
CO2 emissions AND Atmospheric CO2 concentration graph
http://www.eia.doe.gov/oiaf/1605/ggccebro/chapter1.html
Global Temperatures graphs
http://cires.colorado.edu/~maurerj/scatterometry/global_temperatures.gif
http://www.sightedmoon.com/wpcontent/uploads/2006/09/Average%20Global%20Temperature%201880-205.JPG
http://alignment.hep.brandeis.edu/Hashemi/Climate/Global_Temp.gif
Global Temperatures data table
http://www.earth-policy.org/Indicators/Temp/Temp_data.htm#fig5
Atmospheric CO2 concentrations graph (at Mauna Loa, HI)
http://www.grida.no/climate/vital/06.htm
Atmospheric CO2 concentrations table (at Point Barrow, AK)
http://www.fsl.noaa.gov/visitors/education/samii/SAMII_Act6_Table6.1d.jpg
E5.4D
Affects of Climate Change on Oceans
http://www.usgcrp.gov/usgcrp/Library/nationalassessment/overviewcoastal.htm
E5.4e
Varves
http://en.wikipedia.org/wiki/Varve
Cryosphere and Ice Cap Animations
http://www.nasa.gov/centers/goddard/earthandsun/climate_change.html
Affects of Climate Change on Polar Ice (Sea Level Rise)
http://www.usgcrp.gov/usgcrp/Library/nationalassessment/overviewcoastal.htm
Affects of Melting Polar Ice on Regional Climate
http://www.thewe.cc/weplanet/poles/thermohaline_circulation.htm
http://www.windows.ucar.edu/tour/link=/earth/polar/icemelt_oceancirc.html
E5.4g
Greenhouse gases and their heat trapping capacity
http://encarta.msn.com/encyclopedia_761578504/Greenhouse_Effect.html
Good movie to watch: An Inconvenient Truth (Al Gore)