The difference between Tigers and Dinosaurs is that Dinosaurs to our knowledge died from natural causes, not over hunting. If we kill off all the Tigers we leave a gap in the food chain that may or may not be replaced,not to mention that we've lost an incredibly beautiful animal.

As for whether or not environmental issues are over-hyped or not it doesn't really matter, even if what we're doing isn't hurting the environment drastically it's still our duty not to hurt it at all if we can. Precaution is just as important as the cure.

"We submit to the majority because we have to. But we are not compelled to call our attitude of subjection a posture of respect." Ambrose Bierce