The expansion of the Roman Empire was from about 60 B.C. till the Empire's dissolution in 476 A.D., and many of the innovations that Romans brought to other countries were fueled in part by dwindling resources in the area of Rome itself. As the people of Rome used up firewood, and grains became scarcer due to a rising population, it was the human-environment interaction which led to the political and military decisions to conquer other lands.
The location of Rome on the Tiber River is an example of human-environment interaction. The river provided a ready source of transportation for goods required by the ancient Roman Empire, and it continues to be a source of transportation for modern Rome. Silting of the river over the centuries, however, has meant that the river is no longer navigable except at Rome itself.
There are many examples of how humans both affected and were affected by their environment in Rome:
- Rome used up and ran out of local supplies of precious and other metals, so they often needed to import them from conquered lands to the north.
- The ancient Romans built aqueducts to transport water and a network of roadways over the land; many of these are still in use.
- Lead production and other mining activities caused environmental degradation. Lead has been found in the Greenland ice cap, which is believed to date from ancient Roman times.