In the 1980 ’ s, after scientists in Germany studied the effects of air pollution and acid rain on the environment, they concluded: ‘ If nothing is done, about the year 2000, people will be left to admire forests only in old photos and in movies. ’
طوال عقود ،‏ ينبّه انصار البيئة وغيرهم من المواطنين القلقين الى الحاجة الى حماية نظام الارض البيئي .‏