Which of the following is not a possible effect of increasing carbon dioxide levels in the atmosphere?

a. increase in water contamination and floods

b. ocean acidification

c. cutting down forests

d. reduction of cold-related deaths

Out of the following choices, the answer which is not a possible effect of increasing carbon dioxide levels in the atmosphere is cutting down forests. So the answer is. D

The question is asking us "Which of the following is not a possible effect of increasing carbon dioxide levels in the atmosphere?" If you look at option 3, c. cutting down forests, you can see that this is a human activity - and a human activity is caused by human decisions and only indirectly by the level of Carbon dioxide. Therefore, the best answer is c. Cutting down trees