Acid rain is caused by sulfur dioxide and nitrogen oxides emissions from the burning of fossil fuels, which mix with water vapor and fall as rain with a lower pH. It has harmful effects on forests as it damages trees and soil, lakes as it kills fish populations, buildings by corroding materials like stone and metal, and humans by exacerbating respiratory issues. Potential solutions include reducing fossil fuel usage by improving energy efficiency and developing renewable resources, as well as installing pollution control devices on power plants and vehicles.