I am also an environmentalist. I believe overpopulation is at the heart of all our environmental issues. The so-called environmental groups won't touch this issue, because they are afraid it will offend their "progressive" constituency. Instead, they have morphed into marketers, spin masters, and control freaks. In the US, we have groups that want gardeners to grow only those plants that grow native to their local area. These people are crazy for control over other people's lives. Talk to them; listen to them. They are not rational. They are like cult fanatics.
Any group that takes a report like this one and turns it into a doomsday tirade is not our friend. They are using public ignorance about science to feather their own nest. Like any bureaucracy, their first interest is job security.