- Why does the Earth receive radiation from the sun as if the sun is an emitter with an
effective temperature of near 6,000 K, when in fact, the hottest temperatures of the
sun are more than 15 million K? (2pts) - What prevents the Earth from having magma oceans on its surface today, even though
temperatures in the interior of the Earth exceed 4,000 K? (2 pts) - Describe the vertical structure of the Earth’s atmosphere, commenting on the altitude
and temperature of each sphere. You should consider sketching a diagram to help your
answer. (4 pts)
Long Answer and Critical Thinking questions. - Describe the nitrogen cycle and discuss why it is important you may sketch a diagram to
assist your explanation. (4 pts) - a. Describe the process of photosynthesis including the chemical equations. Describe the
inputs and byproducts and why this process is critical for the Earth. (4 pts)
PGEG451 Environmental Geology Spring 2019
Fig. 1. Henrich (2006)
b. The figure above describes the increase in the Earth’s atmospheric oxygen through time
(Ga = billion of years). Discuss what events may have occurred to result in the increase in
oxygen in the Earth atmosphere and why prior to 3.5 GA there was relatively little Oxygen in
the atmosphere. (4 pts) - Energy is a critical component of Earth Systems. Explain the Earth’s energy budget. Consider
the following in your answer What are the inputs and outputs? What other agents act to
effect the Earth’s temperature and how? How does Latitude and longitude effect the energy
reaching the Earth? (6 pts) - There are several circulatory systems on Earth. Describe either Thermohaline circulation or
atmospheric circulation. Draw a sketch of the circulation you have chosen to describe and
discuss how this circulatory system impacts the Earth’s climate. (6 pts.) - See detailed figure in Kemp. 1994 P. 36. Explain Figure 2.14 discussing the positive and
negative feedbacks in the system, and how it affects global climate. (6pts)
Sample Solution