Acid rain is rain with a pH of below 7 that is made through the reaction of nitrogen and sulfur oxides in the atmosphere that mix with water to produce clouds of acidic rain found everywhere from the ocean to the city.
It is caused artificially as a product of factory production or it can occur naturally as a result of volcanic eruptions or decaying vegetation
It causes damage to structures such as the Pyramids of Egypt and the Taj Mahal because it is acidic so it is eroding the material.
Acid rain damages plants and makes them vulnerable to the elements. It also endangers aquatic life by decreasing the pH in which they live in, therefore killing them if they cannot adapt.
There are two types of acid rain, dry deposition, and wet deposition. Dry deposition is when particles of acid rain accumulate and are absorbed into things like plants, whereas wet deposition is when acid is precipitated from the atmosphere to the surface.
Because it is the biggest contributor to producing acid rain, if you found an alternative way of making energy without burning fossil fuels then you would see a significant decrease in the amount of acid rain in an environment.