We probably couldn't sterilize the earth even if the entire humanity wanted it more than anything else and threw everything it had to make it happen and then some more.
Even destroying the entire humanity would be hard, civilization could go, we have plenty of scenarios for that, but killing every human, even the odd tribe of refugees who could survive in a cave somewhere is something else. I'd say it is the maximum extent of what our technology could do. By that I mean nuking everything we could nuke, including things like volcanoes, mass produce all the greenhouse gases, the ozone depleting ones, the poisonous ones just to release them all, have our finest biologists prepare a pandemic, we may even try to bring in some asteroids.
To sterilize the Earth we would need to destroy all the extremophile bacteria, the tardigrades, the deep biosphere,... That's not happening. Note that we are very careful to sterilize Mars rovers, so that we don't contaminate Mars with Earth life. That's how hardy we consider life to be.
Even destroying the entire humanity would be hard, civilization could go, we have plenty of scenarios for that, but killing every human, even the odd tribe of refugees who could survive in a cave somewhere is something else. I'd say it is the maximum extent of what our technology could do. By that I mean nuking everything we could nuke, including things like volcanoes, mass produce all the greenhouse gases, the ozone depleting ones, the poisonous ones just to release them all, have our finest biologists prepare a pandemic, we may even try to bring in some asteroids.
To sterilize the Earth we would need to destroy all the extremophile bacteria, the tardigrades, the deep biosphere,... That's not happening. Note that we are very careful to sterilize Mars rovers, so that we don't contaminate Mars with Earth life. That's how hardy we consider life to be.