Deforestation generally decreases which of the following?

Rainfall

Deforestation generally decreases rainfall. When trees are cut down, the natural process of transpiration, where plants release water vapor into the atmosphere, is significantly reduced. This results in lower atmospheric moisture levels, which directly impacts local and regional rainfall patterns, leading to reduced precipitation.

Additionally, deforestation affects the climate system by promoting global warming. Without trees to absorb carbon dioxide, greenhouse gases increase in the atmosphere, contributing to higher global temperatures. However, deforestation does not decrease global warming; instead, it accelerates it.

Deforestation also leads to soil erosion. The absence of tree roots to hold soil in place causes the topsoil to be washed away by wind or water. This can degrade land fertility and lead to desertification over time. Similarly, deforestation does not decrease drought; in fact, it can exacerbate drought conditions by disrupting the water cycle.

Therefore, among the given options, rainfall is the correct answer to what deforestation generally decreases. To summarize, deforestation has severe environmental impacts, but its direct effect on decreasing rainfall is one of the most critical consequences.