Through most of Earths history, conditions on the surface were inhospitable and fatal to humans.  Plants produce enough oxygen to make the atmosphere breathable.  Humans are doing nothing more than returning things to the way they were for the first 4 and a half billion years of Earth history.

There were likely areas that were too hot for life in the past.  Critters were confined to habitable zones.

There was The Triassic-Jurassic extinction.  Number 4? 



Land was configured in one giant continent. In the middle of this super-continent, near the equator, it must have been hot as hell.  When the continents split apart there must have been a lot of CO2 in the air.  Extinctions were common.



It was certainly too hot for humans then and there.  The only ice on the planet was found on the top of mountains.  But continents we know now were locked together, and not running into each other to form mountains by collision.  Or by seafloor subduction.  Ice was rare.    Reptiles were favored.

There is also chemotherapy by asteroid impact.  A steady regimen of asteroids pills keeps life changing on the Earths' surface.  Old life is eliminated, and new life forms take their place.  * Gaia .

My point is humans are not killing the planet.  The planet is going to sneeze and when it does and we are gone the planet will not be dead.  The planet will be fine.  Just like George Carlin said it would.  Thinking we are killing the planet is hubris.  Thinking we are killing the planet leads to thinking we can fix our climate predicament with GEOENGINEERING.

Which capitalism absolutely WILL NOT PAY FOR.

Ooops, Say Bill, do you know that socialism is necessary for your plan to work?



( If you find this offensive consider that rule by billionaire is equally, or more, brutal. )

* The problem with the Gaia hypothesis is that if you accept it you have to face the fact that Gaia can be one total bitch.  Who periodically wants a divorce and who can make your life a living hell.