I understand and agree AK that possible scenarios have not been ruled out. But I also know that increased energy and nutrients do tend to increase biomass in short timelines not long ones. The reproductive phenomena that causes this is best expressed as living organisms tend to reproduce past the point of an ecosystem’s ability to support. Weeds in particular use this reproductive approach. Other species succeed and replace weeds using their evolutionary advantages.
So, yes, there is a risk of dustbowls. The uncertainty or lack knowledge indicates one should also recognize that there is a risk of a fertile cornucopia. Without evidence otherwise, increased energy and nutrients should lean to cornucopia. The uncertainty is both ways.
You state: “”But more importantly, I’m not talking about long-term ecological effects of more CO2, I’m talking about the interaction with the climate. Seasonal dust bowls in areas that currently don’t experience them could well have enormous effects on the climate through changing the nature of precipitation over large areas of the ocean. As well as down-stream ecological effects through fertilizing areas that currently don’t get much.”” I understand this, but would point out that underlying assumptions that would support this scenario of catastrophe are highly contested.
The general effects of nutrient addition are known on the small scale such that an extrapolation to larger scale stays within the limits of the assumptions and methodology. Climate being chaotic does not extrapolate well, if at all. This is where the risk part generates a lot of concern among those I have read. With large uncertainty, risk factors are generally poorly constrained. But it applies to cornucopia, catastrophe, or status quo being the outcome, not just one or the other.