Which of the following increase the amount of carbon dioxide in the atmosphere?

i. Deforestation   ii. Burning of fossil fuels   iii. Farming   iv. Afforestation

Deforestation and burning of fossil fuels lead to an increase in the amount of CO₂ in the atmosphere.

Deforestation involves the removal of trees, which are natural carbon sinks that absorb carbon dioxide from the atmosphere. When trees are cut down, the carbon that they have absorbed during their lifetime is released into the atmosphere. Burning fossil fuels, such as coal, oil, and natural gas, also releases carbon dioxide into the atmosphere, as well as other greenhouse gases. Farming and afforestation can actually help to reduce carbon dioxide levels in the atmosphere, as plants absorb carbon dioxide during photosynthesis.