1. Carbon dioxide in the atmosphere is taken up by plants to create organic biomass, which then is used for energy by both plants and animals, who respire CO2 back into the atmosphere. This cycle (nature was, after all, the first recycler) is called the

    a. sedimentary component of the carbon cycle.
    b. gaseous component of the carbon cycle.
    c. global carbon cycle.
    d. photosynthetic cycle.
    e. geologic cycle.

2. The time it takes for a carbon atom to cycle from the atmosphere through the biota and back to the atmosphere falls within which range?

    a. two to four hundred millions of years.
    b. two to four hundred thousand  years.
    c. centuries to millennia.
    d. minutes to centuries.
    e. nanoseconds to milliseconds.

3. The time it takes for a carbon atom to cycle from the atmosphere through the biota, then into buried sediments (like coal, oil, or peat) and back to the atmosphere falls within which range?

    a. two to four hundred million of years.
    b. two to four hundred thousand of years.
    c. centuries to millennia.
    d. minutes to centuries.
    e. nanoseconds to milliseconds.

6. According to the text, general circulation models (GCMs) of the atmosphere

    a. produce very specific results as to time and place of climate change.
    b. are now in operation at over a hundred places in the U.S.
    c. are based on statistical three-dimensional boxes that characterize portions of the atmosphere and ocean in terms of climate-related variables.
    d. are unrelated to mathematical models originally established for forecasting weather.
    e. are strictly academic exercises and should not be used to suggest future activities by our society.

7. The many general circulation models (GCMs) of the atmosphere are approaching a consensus as to the state of the global climate in the future. What is the predicted consequence of increased anthropogenic (human-caused) additions of CO₂ to the atmosphere?

    a. Climate change will be spatially heterogenous: although the globe will become warmer, different regions on Earth will be affected differently by global climate change.
    b. Climate change will not be spatially heterogenous: Global climate change will affect all areas of the Earth equally - everybody will be warmer.
    c. Global climate change is totally unpredictable, and the models are not useful for telling the general public how climate may change.
    d. Global climate does not change, so adding CO₂ to the atmosphere will not affect climate.
    e. The higher latitudes will become much warmer, but the mid-latitudes and tropics will not be affected significantly.

8. Which of the following is not a factor in the change of sea level at local places?

    a. Thermal expansion of ocean water as it warms.
    b. Melting of the Arctic ice cap.
    c. Melting of the Antarctic ice cap.
    d. Melting of mountain glaciers.
    e. Increased precipitation on the warmer Earth.

9. Sea level rise on the west coast of Florida has been about 25 cm since 1920. Although coastal forests seem to be healthy, they will not last over the long term (e.g. next 50 years). Why not? (See Williams, K., K. C. Ewel, R.P. Stumpf, F.E. Putz, and T.W. Workman. 1999. Ecology 80:2045-2063 if you weren't in lecture)

    a. Higher sea level results in more saline soil moisture near the coast, which is killing the adult trees.
    b. Higher sea level results in more saline soil moisture near the coast, which results in the lack of germination of new seeds so there are no young trees in the coastal forests.
    c. Higher sea level has no effect on the coastal forests, and the premise of the question is wrong because the forests will be healthy in 50 years.
    d. Higher sea level is drowning the coastal forest in deeper water.
    e. Sea level on the west coast of Florida is the same as it was in 1920; sea level doesn't change therefore the forests are not threatened.

10. Volcanoes may affect global temperatures

    a. because they produce so much heat during eruption.
    b. by increasing the amount of insolation received at the surface of the Earth.
    c. by increasing atmospheric albedo and heat absorption, thus causing cooling at the surface by reducing insolation input.
    d. by clearing the atmosphere of aerosols.
    e. by eliminating the vegetation in large areas via lava flows and explosions, thereby decreasing the Earth's albedo.

10. Over the past 100 years, the average global temperature has

    a. remained constant.
    b. risen about 0.7 C degrees.
    c. decreased about 0.7 C degrees.
    d. been so variable as to show no trend of increase or decrease.
    e. increased during and immediately after years with significant volcanic activity.

11. According to the text, which of the following is not a consequence of a potential global warming over the next 30 to 50 years.

    a. a decrease of 10% in available soil moisture in the midlatitudes.
    b. a longer frost-free season and more precipitation in Russian grain producing regions.
    c. increased temperatures of the Great Lakes.
    d. a continuing rise in sea level.
    e. an increase in ice accumulations worldwide.

12. Which of the following is a predicted consequence of the increased carbon dioxide concentration in the atmosphere?

    a. flooding of low-lying coastal areas.
    b. spread of tropical diseases to regions now unaffected by them.
    c. change in species composition of forest ecosystems.
    d. change in international trade relationships -- especially those pertaining to food.
    e. all of these are predicted consequences of increased carbon dioxide concentration.

13. Which of the following is true regarding the concentration of carbon dioxide in the lower atmosphere?

    a. It is more than 30% higher than during the pre-industrial era.
    b. It has stabilized.
    c. It is presently about 150 parts per million by volume.
    d. It is unrelated to the regrowth of harvested and cleared forests.
    e. It is decreasing due to the "unknown sink," which might be soil organic matter.

14. The plot of atmospheric carbon dioxide concentration through time (see figure) has a long-term increasing trend, but also has a regular, annual fluctuation. What is the cause of this intra-year fluctuation?

    a. Precession of the Earth's axis.
    b. Seasonal variation of terrestrial photosynthesis in the northern hemisphere.
    c. Seasonal variation of carbon uptake by oceanic phytoplankton.
    d. It is an artifact of the measurements - cooler winter temperatures decrease the value as measured by instruments.
    e. Winter measurements are made during the day when carbon dioxide is lower, and summer measurements are made during the night when carbon dioxide is higher.

15. According to the professor in the lecture, what is the major uncertainty about climate change?

    a. Measurements of climate do not show convincingly that climate is changing.
    b. Climate science does not understand the mechanism of climate variation.
    c. Global climate predictions based on general circulation models do not agree with each other about how climate changed in the past, nor about how it might change in the future.
    d. Science has not shown a definite link between Carbon Dioxide in the atmosphere and global temperature.
    e. While climate scientists are somewhat uncertain about the results of their studies, the major uncertainty about climate change is what to do about it.