It's frightening but true: Our planet is now in the midst of its sixth mass extinction of plants and animals — the sixth wave of extinctions in the past half-billion years. We're currently experiencing the worst spate of species die-offs since the loss of the dinosaurs 65 million years ago. Although extinction is a natural phenomenon, it occurs at a natural "background" rate of about one to five species per year. Scientists estimate we're now losing species at 1,000 to 10,000 times the background rate, with literally dozens going extinct every day. It could be a scary future indeed, with as many as 30 to 50 percent of all species possibly heading toward extinction by mid-century. [Center for Biological Diversity website]

OK, one or two weasel words in there, but this is typical of many references you can find to the current man-made mass extinction. I don't think it's necessarily an alarmist view. Dunno about that level of extinction, but there's no doubt that losing diversity is disastrous.