Others have described humans as a cancer that has grown in the biosphere. These are forceful and passionate figurative ways of saying that humans have caused much harm to many other creatures on earth, and are likely to cause more.
But let us not take these too literally.
After all humans have been on earth for well over a hundred thousand years, and this plague-like behavior/impact has been quite recent.
Even the most ardent well-wisher of our Earth will not want humans to be totally eliminated to de-plague the planet.
Of course we need to recognize the harm we are wreaking as a species on the environment, and learn to behave better collectively in this regard, as much in our own interests as for the survival of other creatures.
Ironically a small percentage of humans (leaders, industrialists, governments, profit-mongers, technologists…), knowingly or unknowingly, instigate, cause, and facilitate, the plague-like behavior of the majority.
Spurts of Thought 