Topic #2 The Earth's Changing
Climate
At the top of your paper you will find two grades.
The first is the content grade (you could earn up to 8 pts)
The second grade is the writing quality grade (you could earn up to 7
pts)
Here are some of the details and kinds of information we looked for
when determining the content grade
Changing climate (up to 1 pt)
glacial period ended about 18,000 years
ago
glaciers now cover 10% of land surface (sea level could rise 65
m [213 ft] if this all melted)
Determine past climates (2 - 2.5 pts)
fossil pollen
ocean floor sediments
what organisms were around
oxygen isotope analysis of shells
ice cores
oxygen isotopes
chemical analyses
sulfuric acid means volcanic activity
Climate through the ages (2 pts)
it was 8 to 15
o C warmer in
the past,
poles were ice free
Pleistocene epoch (Ice Age) that we're currently in started ~ 2
million YA
most recent glacial period ended 18,000
to 20,000 YA, this was followed by warming that
was interrupted ~12,700 YA by cooling (Younger Dryas)
Holocene maximum (climatic optimum) = warm period about 6000 YA
Most recent 1000 yrs (2 - 2.5 pts)
1000s-1300s (AD) Medieval climatic
optimum = warm period
relatively warm over W. Europe
1400s - 1800s Little Ice Age = cold spell in Europe
1816 Year without a summer (volcanic eruption)
1900-1945 +0.5o C of warming
1945-1970 slight cooling
1970-present warming
Thermohaline (conveyor belt) circulation (0.5 - 1 pt)
transports heat and moisture to the N.
Atlantic
strong current = warm in N and W Europe
weak current = much colder
influx of fresh water (from melting ice caps and glaciers)
could weaken or shut down the current
Writing grades were awarded as follows:
Excellent (7 pts)
Free of grammatical and spelling errors, clear understanding and
presentation of the material, material presented in an original and
interesting way
Average (6 pts)
An occasional spelling or grammar error, organization and explanations
not much different from what is found in the textbook (this makes it
hard sometimes to judge how well you understood the material)
Below average (5 pts)
Quite a few spelling errors, some confusion or awkward sentence
constructions, incomplete or inaccurate explanations of some of the
material or superficial coverage of the material, the majority of the
report is understandable.
Poor (4 pts)
Report is becoming hard to understand.