Answer:
The correct answer is "The overall temperature of Earth to increase."
Step-by-step explanation:
The amounts of carbon dioxide and methane in Earth's atmosphere are increasing. Carbon dioxide and methane are greenhouse gasses. The increasing levels of carbon dioxide and methane will cause the overall temperature of Earth to increase.
When methane is released into the air, it tends to absorb the heat from the sun and creates a warmer surrounding. This is the reason why they known as greenhouse gases because they warm the atmosphere and therefore increase the temperature of earth.