Answer to Question 1
Answer: Since the middle of the 19th century, there has been an exponential increase in the input of carbon dioxide to the atmosphere by industrial activities (chiefly fossil fuel combustion and cement manufacture). These industrial releases have been augmented by smaller but still significant releases resulting from deforestation. Deforestation adds CO2 to the atmosphere through direct burning of the logged trees, decomposition of biomass, and other processes. Moreover, the removal of trees reduces the ability to remove subsequent inputs of carbon dioxide by photosynthesis.
Answer to Question 2
Answer: C