LIFE SCIENCE

Detailed explanation-1: -Human activities have a tremendous impact on the carbon cycle. Burning fossil fuels, changing land use, and using limestone to make concrete all transfer significant quantities of carbon into the atmosphere.

Detailed explanation-2: -Burning fossil fuels, releasing chemicals into the atmosphere, reducing the amount of forest cover, and the rapid expansion of farming, development, and industrial activities are releasing carbon dioxide into the atmosphere and changing the balance of the climate system.

Detailed explanation-3: -Some of the ways in which humans have affected the carbon cycle include burning fossil fuels, changing land use and destroying forests, and the use of limestone to make concrete. All these changes cause an increase of CO2 in the atmosphere.

Detailed explanation-4: -More carbon is moving to the atmosphere as humans get rid of forests by burning the trees. Burning wood releases carbon into the atmosphere that had been stored in the tree. Most of the carbon in the atmosphere is in molecules of carbon dioxide (CO2).