Exercises: Human disruption and global warming

Burning gasoline, LP gas, or coal releases into the atmosphere carbon that was stored for millions of years in fossil fuels. Explain how this activity, together with deforestation, increases atmospheric CO₂ and why that intensifies the greenhouse effect and global warming.

Two classmates are discussing reforestation. One says: "planting trees is enough to solve global warming"; the other says: "forests are only a temporary carbon sink". Analyze both claims using what you know about the carbon cycle (sinks, carbon storage and release) and explain which combination of actions would be most effective at reducing atmospheric CO₂.