Living Environment Regents Practice Test

What is the most likely change in the atmosphere due to widespread deforestation?

1. Carbon dioxide concentration decreases and oxygen concentration increases

2. Oxygen concentration decreases and carbon dioxide concentration increases

3. Both oxygen and carbon dioxide concentrations decrease

4. Oxygen concentration increases while carbon dioxide remains constant

The correct answer is: Oxygen concentration decreases and carbon dioxide concentration increases

Widespread deforestation significantly impacts the levels of gases in the atmosphere, primarily through the loss of trees that play a crucial role in photosynthesis. During this process, trees absorb carbon dioxide and release oxygen. When forests are cut down, there are fewer trees to absorb carbon dioxide, leading to an increase in its concentration in the atmosphere. At the same time, as trees are removed, the source of oxygen production decreases, which can lead to a decline in oxygen levels. Therefore, in areas impacted by deforestation, the most likely change is that the concentration of carbon dioxide increases due to reduced uptake by plants, while the concentration of oxygen decreases because there are fewer trees to produce it. This shift in gas concentrations can contribute to climate change and various ecological imbalances, highlighting the importance of forests in maintaining atmospheric health.