Had man been alive at the time the Siberian traps erupted humans would have gone extinct.  Does human activity now rival the Siberian Traps in deadliness?  You decide.

If human activity puts the planet at an average of 35 degrees C, there will be large areas uninhabitable because wet bulb temperatures will become fatal.  According to this video, the average due to the ocean methane bomb feedbacks from the Siberian trap eruptions produced an average global temperature of 42 degrees.

So human activity will not rival the Siberian Trap Eruptions because humans will be gone before human activity can yield an average global temperature of 42 degrees.

Humans will not make the planet go Venus. If humans vanish there will be a great greening before the next ice age.  Then ten million years later squirrels will be in charge.