2.7 Scenario-Based Questions
Read the following scenario and answer the questions below.
Almost all environmental scientists agree that gases contribute to global climate change. Carbon
dioxide, methane, nitrous oxide, ozone, halocarbons (CFCs and HFCs), and water vapour are the
main culprits. These “greenhouse gases” have increased dramatically in our atmosphere in the
last 300 years, because of rapid industrialization. Human activities significantly increase
greenhouse gases in our atmosphere. Chief among these is the burning of fossil fuels for energy.
When we burn fossil fuels, we combine the carbon in fossil remnants of an organic matter with
oxygen and release the resulting gasses into the atmosphere. With rising standards of living in
developing countries, emissions of carbon dioxide and other greenhouse gases are expected to
continue to rise. If unchecked, it is predicted that carbon dioxide levels will reach twice
preindustrial levels by mid-century and double again by the end of the century. Computer models
have shown that this increase alone could raise Earth’s temperatures by 1 to 3°C by 2100.
1) The burning of fossil fuels is chemically most similar to which of the following biological
processes?
A) phytoremediation
B) autotrophy
C) chemosynthesis
D) cellular respiration
E) photosynthesis
2) Nitrous oxide from burning fossil fuels, in addition to being a greenhouse gas, contributes to
acid precipitation. This can be explained by ________.
A) its ability to form compounds that raise pH
B) its ability to form compounds that lower pH
C) the ability of acids to raise the temperature of the substances which dissolve them
D) the airborne nature of all compounds containing nitrogen
E) the hydrogen bonds connecting the nitrogen and oxygen atoms in the molecule