Question

if the number of photosynthetic organisms on earth decreased drastically, which would happen as a result? less water would be available on earths surface. less solar energy would reach earths atmosphere. more oxygen gas would be found in earths atmosphere. more carbon dioxide gas would be found in earths atmosphere.

Explanation:

Photosynthetic organisms use carbon - dioxide and release oxygen during photosynthesis. Fewer photosynthetic organisms mean less carbon - dioxide is absorbed from the atmosphere.

Answer:

More carbon dioxide gas would be found in Earth's atmosphere.