Are there any examples of unnecessary damage made to the environment by native groups of the past?
Environmental degradation started quite early in human history and there are numerous examples from across the globe.
One of the most dramatic examples was the deforestation of Easter Island by Polynesian settlers who arrived at the island ca. 400 AD and whose society collapsed due to deforestation by ca. 1600 AD.
Many of the Greek islands also were affected by soil erosion and deforestation in antiquity, including ones where the source of the problem was overgrazing of cattle.
Some scholars think that the collapse of the Anasazi culture may have been prompted by overpopulation and environmental degradation. Desert environments tend to be very fragile, and many of the places where people lived in the Four Corners area are notably slow to recover from even the damage caused by human footsteps.
Native Americans caused soil erosion and changed the pattern of floodplains in the area of modern Delaware.