The "author" is either disingenuous or completely naive. The vast majority of "animal-rights" and "pro-environment" types believe that the human race is a cancer on the face of the planet, and the more that are killed off (except for themselves, of course), the better.
Wow. Way to sterotype - the same way pro-aborts sterotype pro-lifers as women-haters.
The next paragraph of the same article:
I am personally aware of a few cases in which political opponents of the "Religious Right," even ACLU members, have made common cause with the pro-life movement. Consider, for example, the upcoming book, The Liberal Case Against Abortion by animal rights activist Vasu Murti.