That's good food for thought; whaling is perhaps another good example. But previous generations had less capability to exhaust nonrenewable resources than more modern ones, and the side effects of killing all the Syrian Elephants might be less harmful than the side effects of blowing the tops off of mountains.

Similarly: most species extinctions seem either to have occurred BCE or after the industrial era. The older extinctions caused by people who knew less about the impact of their (for instance) hunting, which makes them less morally culpable.

You are right, and there are many ways in which the world has objectively shown uninterrupted progress throughout history. Murder/violence have apparently been steadily decreasing since biblical times[1]. The same probably goes for other things, like prejudice and freedom of expression.

Also there is the important point that problems like environmental harm seem more acute now only because we are more aware of them. During the industrial revolution, the extent of the harm caused by the use of fossil fuels wasn't a consideration to anyone because we couldn't even conceive what it would mean. Ignorance is bliss.

Unfortunately, all of this is cold comfort when you have dark thoughts of widespread conflict over fresh water in your future.

[1] http://www.ted.com/talks/steven_pinker_on_the_myth_of_violen...