Chapter 15: Climate Change
Chapter 15.1: What is the Atmosphere

Earth’s Atmosphere: Retains solar heat, protects us from radiation in space and
distributes water in our body. Consist of gas molecules held down by gravity.

Weather: short and local patterns of temperature and moisture that result from circulation
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Climate: long term patterns of temperature and precipitation

Aerosols: minute particles and liquid droplets (important in capturing, distributing, or
reflecting energy).
1) Atmosphere four district zones
a. Troposphere: Adjacent to Earth’s surface
i. Air absorbs energy from surface and moisture
ii. Air Circulates in vertical/ horizontal convection currents(warm, low
density air rises above cooler, denser layer)
iii. Contains 75% of total mass atmosphere
b. Stratosphere: Similar composition as troposphere except no water vapor and more
ozone
i. Ozone absorbs wavelengths of ultraviolet solar radiation(UV-B)
1. UV-B warms stratosphere, so temperature increases with elevation
and protects human from skin cancer
c. Mesosphere: Temperature diminishes
d. Thermosphere: Ionized gases heated by high energy solar and cosmic radiation
i. Radiation causes ion to glow known as aurora borealis/ australis or
northern and southern lights
2) Absorbed Solar Energy Warms Our World
a. Sun supply large amounts of energy, not evenly distributed
b. Incoming Solar Radiation (Isolation) stronger near equator
c. One fourth of sun’s energy is reflected by clouds and atmospheric gases
d. One fourth is absorbed by carbon dioxide, water vapor, ozone, etc…
e. Two fourths of sun’s energy reaches earth’s surface
i. High Albedo: Surface reflect energy
ii. Low Albedo: Surface absorbs energy
f. Water is extremely efficient at absorbing and storing energy, accelerating ice
melting and atmospheric warming
3) Greenhouse is Energy Captured by Gases in the Atmosphere
a. Energy rerelease from Earth’s surface (terrestrial energy) is lower in intensity and
longer wavelength radiation
b. Greenhouse effect: transmits sunlight while trapping heat inside
c. Greenhouse gases:
i. Water always present in atmosphere
ii. Carbon dioxide long lasting human caused gas
iii. Methane (CH4), nitrous oxide(N2O), ect…
4) Evaporating Water Stores Energy and Wind Retribution it
a. Solar energy absorbed by ground reradiates as heat, this energy warms lowest
layers of air
b. Convection cells: rising warm air produces vertical convection currents
c. Hadley Cells: equatorial convection cells
i. Circulation is more vigorous
d. Ferrell Cells (mid-latitude) & Polar Cells
i. Less intense heating and less vigorous circulation
e. Low air pressure = air rising in convection currents
f. High air pressure = air sinking or subsiding in convection currents
Chapter 15.2: Regional Patterns of Weather
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Weather: Temperature, winds, and precipitation
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Rains because water condenses as air cools and air cools as it rises
o Regions with solar heating, colliding air masses or mountains tend to rain often

Condensation Nuclei: Particles of smoke, dust, sea salt, and volcanic ash form a surface
which water molecules begin to coalesce
o Without this super cold vapor remains gas
1) The Coriolis Effect Explains Why Winds Seem to Curve
a. Coriolis Effect: Curvature of winds
i. Creates predictable wind patterns and current
ii. Cyclonic winds: wind movement controlled by Earths spin
1. Spiral clockwise in high pressure
2. Spiral counterclockwise in low pressure
b. Jet streams: wind that circle Earth
i. Follow path of vertical convection currents (Hadley & Ferrell) where cells
meet
ii. Greatly affect weather patterns
2) Ocean Currents Modify our Weather
a. Warm and cold ocean currents influence climate change
i. Surface water moves, deep water replace it, creating ocean currents
b. Gyres: Huge water currents carrying water North and South redistributing heat
3) Quantitative Reasoning
a. Ocean circulation patterns change abruptly
i. Melt water affects the flowing of a current by flooding of the melt water
4) Seasonal Rain Supports Billions of People
a. Monsoons: regular season of rain
i. Hot land surface produces strong convection currents, causing heavy rain
b. Tropical regions have seasonal rainy and dry seasons
i. Main reason is intense heating and evaporation shifts through the year
c. Tilt of axis creates seasons
5) Frontal System Occur Where Warm & Cold Air Meet
a. Front: Boundary between two air masses of different temperature and density
i. Cold front: Cool air pushes warmer air
1. Upward forced warm air cools and its cargo of water vapor
condenses to rain/ snow
2. Strong pushed warm air creates violent winds and thunderstorms
ii. Warm Front: advancing air is warmer than surrounding air
1. Warm front has many layers of clouds
2. Moist warm front = drizzle and cloudy skies
6) Cyclonic Storms Can Cause Extensive Damage
a. Cyclonic Storms: released heat intensifies circulation, creating swirling winds of
still more moisture and latent heat energy
b. Hurricanes: Powerful winds (200 mph) drive water inland
c. Tornadoes: Swirling funnel clouds
i. Dry air cold fronts collide with warm air
Chapter 15.3: Natural Climate Variability
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Milankovitch Cycles: Main drives in long term changes
1) Ice Cores Tell us about Climate History
a. Small amounts of air trap in snow layers
i. New layers compress lower layers into ice, and air bubbles still remain
1. Each bubble = sample of atmosphere at time of snow fall
b. Look at isotopes of oxygen to reconstruct temperature over time and plot
temperature changes against concentrations of Carbon Dioxide and other
atmospheric gases
i. Water with lighter oxygen atoms evaporate easier than water with heavier
Isotopes
ii. Isotopes = oxygen atoms
c. Ice core data shows climate is warmer than ever since the development of
civilization, agriculture and urbanization
2) El Nino is an Ocean-Atmospheric Cycle
a. Oscillations, or periodic shifts, in ocean currents and atmospheric circulation
i. El nino: weakened upwelling currents
ii. La nina: coastal waters become extremely cool
b. ENSO(El Nino Southern Oscillation): related droughts/ flood are expected to
intensify and become more irregular with global climate change
i. Increased cloud cover would raise the albedo while upwelling convection
currents generated by these storms could pump heat into the stratospheremight have an overall cooling
Chapter 15.4: Anthropogenic Climate Change

Anthropogenic: Human caused
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Graph first made by Charles Keeling is one of the first and important pieces of evidence
proving human impacts on atmospheric CO2
o Pattern in annual variation in CO2 concentrations
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CO2 levels drop as plant growth capture CO2 in photosynthesis

During winter levels rise as respiration releases CO2
o CO2 levels rise at accelerating rate
1) IPCC Assesses Data for Policymakers
a. Intergovernmental Panel on Climate Change(IPCC): Bring scientist and
government to review causes and effect of climate change
i. Certain climate change is caused by humans
b. Droughts, heating, hurricane frequency (caused by warming oceans and
atmosphere) = human and economic cost
c. Flooding of populous areas in the future will be caused by sea level increase of 3
to 6 feet
2) Major Greenhouse Gases
a. Carbon dioxide: contributes to 76% of human caused climate impacts
i. Fossil fuels = greatest sources of carbon dioxide
ii. Deforestation and other land use = second biggest factor
b. Methane (CH4): second most important greenhouse gas, 14% of greenhouse
output from agriculture
i. Produced when plant matter decays in oxygen free conditions
ii. Released from natural gas wells
1. Ex: Cows Burps
c. Nitrous Oxide (N2O): Third most important greenhouse gas, 8% of greenhouse
gases
i. Released from agriculture process, plant decay, vehicle engines, ect…
ii. Very effective at capturing heat
d. Carbon Dioxide (CO2): equivalent per year (Gt CO2 eq/ yr) compare effects of
these sources
3) Positive Feedbacks Accelerate Change
a. As peat thaws and dries, it oxidizes and decays, release more CO2 and CH4
b. Release of vast stores of frozen compressed CH4, (now locked in permafrost and
ocean sediments) have ominous consequences
i. Release of 2 carbon stores = CO2 levels of all fossil fuels ever burned
4) How do we Know that Recent Changes is Caused by Humans?
a. Uncontrolled experiment: injecting CO2, MH4 and others into atmosphere and
observing changes
b. Build a computer model; complex set of equations
i. Includes natural fluctuation variables and human caused variables
c. Run model to see if it creates past changes
i. Predict past very good, then model works
ii. If predicts past well, then leave out variables till it becomes a very good
model
Chapter 15.5: What Effects Are We Seeing?
1) Effects Include Warming, Drying, & habitat Change
a. Polar Regions warming increased 7 degrees F.
i. Permafrost is melting; houses, roads pipelines, etc…
ii. Transmission lines damage as ground sins beneath them
iii. Trees tipping over
iv. Beetle infestation are killing pine and spruce forest
b. Arctic sea ice decreased by more than 1m km^2
i. Polar bears depend on ice to hunt seals
ii. Devastating for Inuit people, whose lifestyle depends on ice for travel and
hunting
c. Melting glaciers and Ice caps contribute 1 mm
i. Ice shelves on Antarctic Peninsula are breaking up and disappearing
rapidly
1. Penguin population decline because they feed and breed on ice
shelves
ii. Greenland ice caps melting twice as fast
1. Raise sea levels by 23 ft if all of it melts
d. Droughts has expanded and deepened in agriculture regions
i. Killed billions of trees, releasing 8 billion metric tons of CO2
ii. Warmer winters and drier summers
e. Oceans absorbing CO2 and storing heat
i. Acidifying the oceans, which alter marine communities
f. Four key elements for combating climate change:
i. Emission trading to promote cost effective emissions reductions
ii. Share clean energy techniques and accelerates spread of that technique to
developed countries
iii. Reduction of deforestation
iv. Help poor countries adapt clean environment use techniques
2) Rising Sea Levels Will Flood Many Cities
a. South pacific nation of Tuvalu has already abandoned its island home moving to
New Zealand
b. Loss of land and structures to flooding and coastal erosion with damage of fishing
stocks, agriculture, and water supply will multiply cost of climate change
3) Why do we Still Debate Climate Change?
a. Change is threatening, so we ignore it
b. Lack of information
c. Scientist look at data; public impressed by one or two recent events
d. Industry dedicated to disputing evidence of environmental change
Chapter 15.6: Envisioning Solutions
1) Kyoto Protocol & BICEP
a. Countries to voluntarily set their own targets for reducing emissions: CO2 & CH4
& N2O
i. Poor countries exempt to sign
ii. U.S declined to sign
b. In total emissions, have risen to 170%
c. Countries who signed Kyoto Protocol, have met their reduction targets
d. Carbon trading (Cap-and-Trading systems): Legal limits are on emissions and
countries can sell emission credits(right to pollute)
e. Businesses are aware of changing rules, and are willing to accept new standards if
they are clearly and fairly applied
i. BICEP (Business for Innovative Climate & Energy Policy): asked Obama
to reduce greenhouse gases by 80% by 2050
2) Stabilization Wedges could Work Now
a. Stabilization wedges: work by expanding available technology
i. Energy conservation and renewable fuels will help lower CO2 emissions
ii. Capturing and storing carbon releases could save more