Answer must be in essay form. Outline form is NOT acceptable. Labeled diagrams may be used to supplement discussion, but should be explained in your essay. It is important that you read each question completely before you begin to write.

 Global temperatures throughout the Earth’s history, since the origin of life, can be
estimated utilizing a common, albeit primitive organism call foraminiferans. Foraminiferans
incorporate calcium carbonate, CaCO₃, in their bodies as they grow. The oxygen in CaCO₃
may be of two different isotopes, which are sensitive to temperature. The oxygen derives
from water. The two isotopes are: H₂¹⁸O and H₂¹⁶O. H₂¹⁶O has less mass and evaporates
more rapidly in warm temperatures than H₂¹⁸O. Consequently deposits formed during
warming trends are characterized by large amounts of H₂¹⁸O compared to H₂¹⁶O. When it is
a cool (like ice age) period on Earth, then there will be a ratio closer to parity of
H₂¹⁸O:H₂¹⁶O.
Using the ratio of isotopes is one way to determine trends of global temperatures, which
appear to be cyclic. At the present time, global temperatures are climbing more rapidly than
at any other warming period in the Earth’s history. The current rate of global temperature change is an increase of 0.5^oC/decade (up to 1980).  Keep in mind this is an average, some parts of the Earth are exhibiting greater increases in temperature, while the oceans of the Earth are lagging behind the average global increase in temperature. Explain the discrepancy of the atmospheric temperatures and oceanic temperatures, using the properties of water. Predict consequences of continued increases of CO₂ in the troposphere, once again using properties of water, for plants and and animals. Utilize three different properties of water. 12 points

A. For each property, identify and define the property and explain it in terms of the
physical/chemical nature of water.

B. For each property, describe one example of how the property affects the functioning of
living organisms in the future, if current trends persist.

C. Explain hydrogen bonding of water molecules as it pertains to the property.