What you learned in school
Environmental science classes initially taught that acid rain was a localized problem affecting only areas immediately around pollution sources like power plants and factories. Students learned about sulfur dioxide and nitrogen oxides causing acidity in nearby lakes and forests. The problem was presented as contained within a few miles of emission sources. Textbooks focused on local environmental damage without discussing the potential for pollutants to travel long distances through atmospheric circulation.
What we know now
Environmental science classes initially taught that acid rain was a localized problem affecting only areas immediately around pollution sources. Students learned about sulfur dioxide and nitrogen oxides causing acidity near power plants and factories. Acid rain was discovered to be a regional and international problem, with pollutants traveling hundreds of miles through the atmosphere. Acid precipitation affected forests, lakes, and buildings far from emission sources. This led to international cooperation on air pollution control and demonstrated how environmental problems can cross political boundaries. The scale and reach of acid rain were initially underestimated.