producers take in carbon dioxide gas during photosynthesis. they use carbon from the carbon dioxide ot make food molecules. when consumers eat producesr they take in the carbon-contaiing food molecules. when consumers break down these food molecules to obtain energy, they rlease carbon dioxide and water as waste products. when producers and consmers die, decomposers break down their remains and return carbon compounts to the soil. some decomposers also release carbon dioxide as a waste product.