"Acid Rain" was first identified in:

The identification of "Acid Rain" has roots in research conducted in England during the 19th century, making this the historically accurate choice. Scientists, notably in the industrial regions of England, observed the effects of sulfur dioxide and nitrogen oxides on plant life and water bodies. They linked the pollution from burning fossil fuels to the acidic precipitation that began to adversely affect ecosystems, including soil degradation and water quality issues.

This scientific inquiry paved the way for broader environmental awareness surrounding the impact of human activities on natural processes, leading to significant environmental policy discussions later on. Awareness in other countries, such as the US and Sweden, developed over time and was influenced by the earlier work done in England, which serves as a focal point for the study of acid rain.