Review Outline for Exam 3
Difference between weather
and climate
Give some examples of important climate information
that cannot be determined from knowing the “average” temperature and
precipitation for a location.
Why is the magnitude and frequency of extreme weather
events so important in characterizing the climate of a given region?
What is the definition of climate change?
Factors that control the
climate of a particular region as well as factors important in day to day
variations at a given location
Latitude
Elevation and proximity to mountain ranges
Proximity to the Oceans
Reasons why Oceans moderate temperature
changes compared with continental regions
Relative humidity
Soil moisture (or surface wetness)
Cloud cover
Type of surface
Natural emission of radiation
All objects emit radiation. How do the amount
radiation energy emitted and the type of radiation emitted by an object depend
on its temperature?
Compare radiation emitted from the surface of the Sun
with that emitted by the surface of the Earth.
What do the terms
transmission, scattering, and absorption mean with regard to radiation?
How do atmospheric gases and clouds interact with
ultraviolet, visible, and infrared radiation? Generally understand the
energy budget of the Earth with respect to solar radiation. (Most
absorption occurs where? Reflection?)
Be able to explain blue skies, white clouds, red
sunsets, and haze
Energy balance for a planet
Relationship between energy in, energy out, and
temperature changes
Radiative equilibrium temperature
Describe the basics of the
atmospheric greenhouse effect (I do not expect you to be able to give a
detailed explanation)
Which two gases are the most important greenhouse
gases in Earth's atmosphere?
How strong is the greenhouse effect on Earth?
Compare with Venus.
What is the difference between the terms “greenhouse
effect” and “global warming”?
How do clouds influence the surface temperature of the
Earth? Describe how clouds can act to cool the surface. Describe
how clouds can act to warm the surface.
Energy balance for the
Earth’s surface and atmosphere individually
Know the material at the bottom of the lecture web
page “Earth’s Energy Budget II”.
Significance of radiation imbalances for surface and
atmosphere. This drives the vertical or overturning atmospheric
circulations (latent heat transfer), and establishes overall energy balance at
surface and in the atmosphere.
Significance of radiation imbalances at different
latitudes. This drives much of the horizontal atmospheric and oceanic
circulations, and establishes overall energy balance at different latitudes.
Recent increases in
greenhouse gases (CO2, N2O, CH4, CFCs and CFC
substitutes)
measured trends (do not memorize numbers) for each
anthropogenic sources for each
Carbon cycle
Understand the fluxes between the land reservoir and
the atmospheric reservoir: photosynthesis and respiration, decay
How have humans altered the natural balances in the
carbon cycle? Describe the two human activities that are responsible for
increasing the concentration of CO2 in the atmosphere.
Be able to explain the “missing sink” issue for
atmospheric CO2.
Climate feedbacks
Be able to identify/distinguish positive and negative
feedbacks
Understand the specific examples given in class
Climate modeling and Impact
Studies
Examples of how climate models are tested
Uncertainties in climate model projections
Why do different climate models give us different
predictions of future climate? What is the approximate range of predicted
change in global average temperature by the year 2100?
Difficult to model all the complexities of climate,
including feedbacks
Relative uncertainties in model predictions Global
average changes vs. Regional changes in climates
Uncertainties in the results of impact studies
Possible consequences of global warming
Historical temperature record
Examples of proxy records
Climate has never been constant
Climate before the Pleistocene Epoch compared with
today
Climate of Pleistocene Epoch
Ice age cycles. How long ago was the peak
glaciation of the last ice age? Based on the recent pattern of ice age
cycles, when is the next peak glaciation expected?
Climate of Holocene Epoch
Time and Significance of the Younger Dryas event
Time and Significance of the Holocene optimum
Time and Significance of Medieval Warm Period and the
Little Ice Age.
Recent (measured) temperature
record
What do temperature measurements taken in boreholes
tell us about the global temperature changes over the last 500 years?
General description of temperature variations since
1860
Which two periods are inconsistent with global warming
predictions (see handout)? Can any of these periods be explained by those
who believe that recent global warming is primarily caused by greenhouse gas
increases?
Which periods are consistent with global warming predictions?
How might this be explained by those who think the recent warming is not caused
by greenhouse gas increases?
Be familiar with the items
listed on the “Global Warming Summary Sheet.”
Read the Scientific American article and Is the Earth's Climate Fragile or Robust excerpt.