[jlaternman]

I agree that, obviously, large scale asteroid impacts and other major cataclysms have exponentially bigger immediate destructive outcomes. Ridiculously so.

That doesn't mean the atmosphere itself, and the weather systems governing them, don't have to be kept in balance from the inside. It's a different kind of threat, man-made effects on the planet, sustained and over time. Two different systems – one where the life-sustaining systems suffer an acute disruption but then can naturally restore itself over time, and another where the nature of the system itself could slowly be adjusted, potentially compromising its basic life-sustaining qualities.

I wouldn't say it's a bigger threat than large asteroid impacts or cataclysmic events – though, those are relatively minuscule percentages, where the other is something approaching 100% on our current trajectory –, but that doesn't mean it can be dismissed as a threat in itself to the planet's life-sustaining properties. Every threat merits attention, regardless of how they compare.

And the threat is not about human effort, it's about ignorant human hubris.