To understand the kinds of things we're up against, let's begin with a few facts (and sentences) lifted from the May-June Mother Jones article by Julia Whitty on the sixth mass extinction.
After a die-off -- the previous five in the past 400 million years or so each wiped out between 50 and 95 percent of all the life of the day -- it takes 10 million years before biological diversity even begins to approach the level that existed before the die-off. That's a long time!
The current causes of extinction -- "habitat degradation, overexploitation, agricultural monocultures, human-borne invasive species, human-induced climate change" -- in short, capitalism, are accelerating into the 21st century. (I use "capitalism" as shorthand for the system of production and investment based on private profits that has wildly increased world material consumption, and is often referred to euphemistically as "industrialism". Now that the Soviet Union is no longer in the picture, we need not be concerned with the ecological burden of the "state capitalist" system whereby "private profits" were in the hands of the state managers.)
Fully 40% of examined species are in danger, including 1 in 4 mammals, 1 in 8 birds, 1 in 3 amphibians, and 1 in 3 conifers and other gymnosperms. (And remember, certain "keystone species" influence and support a myriad of plants and animals. Army ants, for instance, are known to support 100 other species, from beetles to birds.)
According to E.O. Wison, (oddly enough, a great believer in the corporate enterprise) our current course will lead to the extinction of half of all plant and animal species by the year 2100. Wilson also estimates the current rate of extinction at 1,000 to 10,000 times the background rate. No wonder then that seven out of ten biologists believe mass extinction poses a more serious environmental problem than global warming!
Unlike other critics I cannot take solace in the fact that life will continue long after we're gone. You know, the type of "deep ecology thinker" who pines for a human-free planet or the Buddhist "sage" who revels in existential bliss. I want to do what I can to save the life we have right now.