Across
- 1. Human activities are disrupting the _____________ balance of the carbon dioxide-oxygen cycle.
- 3. This is the source of energy for photosynthesis.
- 5. A process that makes food occurring in plants only .
- 8. Green _________________ produce oxygen and use up carbon dioxide from the atmosphere.
- 9. A gas produced by photosynthesis.
Down
- 2. This process produces energy in the cells of living things.
- 4. CO2 is the chemical formula for carbon _________________.
- 6. _____________ warming is caused by an increase in greenhouse gases in the atmosphere.
- 7. Burning of these fuels, e.g. oil, is producing more carbon dioxide gas.