I must disagree with you. We're not "deliberately destroying" our environment, we are producing the resources we have available to us, in as environmentally conscious a way as we can. I have worked in the oilsands in northern Alberta, and even the largest surface mining projects up there are only a couple of square kilometres in size.
The company that I worked for is very aware of the impact surface mining has on the environment, and has worked hard at improving other techniques such as Steam Assisted Gravity Drainage (SAGD) that have a much smaller impact on the environment (not much more than conventional oil production), and SAGD has been found to have an even higher efficiency throughout most of the oilsands, and I believe it will be one of the most used technologies going forward.
Any way you look at it, resource production of any kind will damage the environment. The point is how government regulations and companies deal with it, and I think Alberta and the oil companies involved are doing at least an acceptable job of managing those responsibilities.