Both deforestation and drilling oil wells can reduce what?

Drilling oil wells reduces deforestation. The oil extraction process results in the release of toxic drilling by-products into local rivers, while broken pipelines and leakage result in persistent oil spillage. In addition, the construction of roads to access remote oil sites also signifies take trees out of the way.

Deforestation reduces the habitat for millions of species. Eighty percent of Earth’s land animals and plants live in forests, and many cannot survive the deforestation that destroys their homes.  It also affects climate change. Forest soils are moist, but without protection from sun-blocking tree cover, they quickly dry out. Trees also help perpetuate the water cycle by returning water vapor to the atmosphere. Without trees to fill these roles, many former forest lands can quickly become barren deserts.

answer; correlational;