I'll try to put it more clearly.
1. We don't really understand how these systems work. (The evidence for that is basically a lack of evidence and the type of thing we are still working on...) 2. Certain outcomes in the system could be very very very bad. 3. We are changing part of the system massively. 4. Because of (1) we don't know what (3) will do.
I'm not alluding to any hiden knowledge here. I'm not a climate scientist. My published work is related to other parts of the Earth's carbon cycle.
The problem with the argument is, well, why doesn't this apply to everything? Massive changes happen all the time in the world, and anything could be a disaster if our only standard for "could" is lack of knowledge that it won't be. If someone said "we need to focus our global efforts on stone-faced office buildings, because humanity might go extinct if we keep building so many all-glass ones", we'd demand more than a lack of evidence.
> The problem with the argument is, well, why doesn't this apply to everything? Massive changes happen all the time in the world, and anything could be a disaster if our only standard for "could" is lack of knowledge that it won't be. If someone said "we need to focus our global efforts on stone-faced office buildings, because humanity might go extinct if we keep building so many all-glass ones", we'd demand more than a lack of evidence.
I can't think of any comparible examples where human activity is known to be causing massive problems... Various forms of pollution maybe? But I would argue for action there too.