You're familiar with the Gaia Hypothesis, that organisms interact with our planet to form a self-regulating complex system that contributes to maintaining the conditions life needs.
Now meet Peter Ward's Medea Hypothesis:
... the Medea Hypothesis in which complex life, instead of being in symbiotic harmony with the environment, is actually a horrible nuisance. In this hypothesis, the planet and microbial life have worked together multiple times to trigger mass extinction events that have almost succeeded in returning the Earth to its microbe--dominant state. In other words, Mother Earth might be Microbe Earth and she might be trying to kill her kids.
The Medea hypothesis is a term coined by paleontologist Peter Ward for the anti-Gaian hypothesis that multicellular life, understood as a superorganism, is suicidal; in this view microbial-triggered mass extinctions are attempts to return the Earth to the microbial dominated state it has been for most of its history. It is named after the mythological Medea, who killed her own children. Medea represents the Earth, and her children are multicellular life.
Past "suicide attempts" include:
Methane poisoning, 3.5 billion years ago
The oxygen catastrophe, 2.7 billion years ago
Snowball earth, twice, 2.3 billion years ago and 790–630 million years ago
As Nathan Curry says,
Well-respected scientists and journalists have come to some scarily sane-sounding conclusions about the threat human-induced climate change poses to the survival of the human species.
Recent data seems to suggest that we may have already tripped several irrevocable, nonlinear, positive feedback loops ... and an average global temperature increase of only 2°C by 2100 ... seems like a fairy tale. Instead, we’re talking 4°C, 6°C, 10°C, 16°C (your guess is as good as mine) here.
The link between rapid climate change and human extinction is basically this: the planet becomes uninhabitable for humans if the average temperature goes up by 4° to 6°C. [emphasis mine]
His article cites "Guy McPherson, who runs a blog called Nature Bats Last. McPherson is a professor emeritus of Natural Resources and Ecology and Evolutionary Biology at the University of Arizona who left his cushy tenured academic career and now lives in a straw house on a sustainable commune in rural New Mexico...", James Hansen, Bill McKibben and Peter Ward.
Let's acknowledge and internalize their messages, despite our fear. Otherwise we'll "just tumble off the precipice, drunk on fossil fuels..."