Question

How do humans cycle carbon from the biosphere to the atmosphere?

Answers:

by respiration
by planting vegetable crops
by eating plants
by driving cars that use gasoline for fuel

Answer 1

Humans cycle carbon from the biosphere to the atmosphere primarily through **respiration** and **driving cars that use gasoline for fuel**.

1. **Respiration**: When humans and other organisms breathe, they metabolize organic carbon compounds (from the food they eat) and release carbon dioxide (CO2) back into the atmosphere as a byproduct.

2. **Driving cars that use gasoline for fuel**: The combustion of gasoline in vehicles releases carbon dioxide into the atmosphere from the carbon stored in fossil fuels derived from ancient organic matter.

While **planting vegetable crops** and **eating plants** are part of the carbon cycle, they primarily involve the uptake of carbon dioxide from the atmosphere through photosynthesis rather than directly cycling carbon back into the atmosphere.

Answer 2

pick one answer