What does a "carbon footprint" refer to? a. the amount of carbon dioxide a human breathes out b. the amount of carbon dioxide a plant absorbs c. the amount of carbon dioxide released by decomposers d. the amount of carbon dioxide a person produces

Why are carbon dioxide concentrations expected to increase? a carbon dioxide concentrations are expected to increase, because fossil fuel burning is expected to increase b. carbon dioxide concentrations are expected to increase, because of an increase in agriculture. c.carbon dioxide concentrations are expected to increase, because more land will have to be cleared for increasing populations and agricultural use. d. all of the above select the best answer from the choices provided mark this and return save and exit next submit submit