Well, though the article did not cite anything, and thus you are quite right to be skeptical, I can tell you that if you look into the existing research you'll find that many of those assertions are based in fact. I can't say that for all of them, because I am not as familiar with saguaro cactus or orang-utans (which actually is the correct common-name spelling). However, it is true that many researchers are concerned that as the polar ice retreats (and it is doing so now), the polar bear will become endangered, if not extinct, because it does rely on extensive ice fields as a hunting ground for seals. The article is also correct about the dire circumstances facing Malaysian tigers. At any rate, we are overusing the resources of the planet and making large changes to various ecologies, so it isn't surprising that we're pushing many animals to extinction. Especially those animals that are specialists to specific habitat types, or are animals that require a large territory.