Question

rainforests around the world are being cleared at an alarming rate to make room for new communities, agriculture, mining, and roads, and to provide lumber for construction and furniture.
how might the destruction of rainforests affect the balance of gases in earths atmosphere?
○ by increasing carbon dioxide and decreasing oxygen
○ by increasing carbon dioxide and increasing oxygen
○ by decreasing carbon dioxide and increasing oxygen
○ by decreasing carbon dioxideand decreasing oxygen

Explanation:

Rainforests have trees that perform photosynthesis (taking in $\ce{CO_2}$, releasing $\ce{O_2}$) and respiration (releasing $\ce{CO_2}$, taking in $\ce{O_2}$), but photosynthesis dominates, so they act as carbon sinks and produce oxygen. When rainforests are cleared, trees are removed (so less photosynthesis: less $\ce{CO_2}$ taken in, less $\ce{O_2}$ produced) and decomposing/ burning of biomass releases $\ce{CO_2}$. Thus, $\ce{CO_2}$ increases and $\ce{O_2}$ decreases.

Answer:

A. by increasing carbon dioxide and decreasing oxygen