Space/Science — HabitableZone

Space/Science » in reply to No

Maybe
ER — (archived)

Feedback mechanisms such as the one you point out can impose a great deal of stability onto the system, and there are many of them operating on earth, as the long history of life on this planet can testify.

However, sudden transients can also reach a point where the system has to alter its parameters before a new oscillatory equilibrium can be reached. And the new mode may be quite different from the one it replaces, both in period and amplitude. That may be why we have ice ages, or extremely warm spells (which don't leave as obvious geological evidence). The fact that eons of colossal volcanic and astronomical events have never succeeded in provoking a runaway greenhouse effect is evidence that, in the long term at least, the earth's climate is fairly stable. But in the short term, a lot can happen as the mechanisms adjust. Life on earth may have survived the ice ages, but it's unlikely our agriculture and industry could adjust in time to a warming of similar magnitude occurring in a relatively short time.

It's precisely because our understanding of the system is so poor that we have to always err on the side of caution.

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