I recommend you reconsider and reexamine this. The abuse of human and environment alike predates the arrival of Europeans by millenia.
This is an excellent resource:
http://www.amazon.com/1491-Revelations-Americas-Before-Columbus/dp/140004006X
Mass extinctions, large scale environmental engineering, resource-driven societal collapses.... All these things have been around for a long time in N America.
I concede you may be correct with this: have you ever read Jared Diamond's "Collapse"? My point is, however, that environmental domination has been historically encouraged by traditional Christianity (contrary to the stewardship principles present in other parts of the Bible). I think Manifest Destiny is one of the largest examples of this, on a collossal scale.
My argument is better restated that Christianity does not have the most prominent role in unsustainable use of the environment (cultures around the world have shared in this for eons as you bring out), but that it is a very ignorant thing to say that atheists have done so. In fact, I would say that athiesm and agnosticism breeds a better understanding of science, since only then does everything stand on its own merits... there's no universal scheme to obfuscate the search for truth; natural processes are revealed for what they are, without being malformed to fit Biblical doctrine. This is not to say that science and athiesm/agnosticism has not exhibited environmental and human exploitation, but that Christians are some of the first ones to rationalize using earth's resources unsustainably, since, if the Earth is going to be burned in fire or whatever, what's the point in leaving anything for future generations? In fact, it seems that most monothiestic religions believe similarly.
Some Christians rightly place more importance on the themes of a stewardship role of the Earth, but it is by no means a consistent message throughout the Bible. it seems to vary author by author.