AK, using biologics as proxies is always prone to biologic responses.
However, the range and uncertainty of all the proxies does not support ‘constant’ nor 300ppm.
We know what happens to many plant species in 1000ppm CO2 environment, because we create those environments on purpose in greenhouses for the benefit.
As I mentioned before, this doesn’t prove that raising the pCO2 to 800-1000ppm would produce catastrophe
Doesn’t prove – doesn’t even indicate.
but there is certainly the risk that it would produce sudden changes to the climate, the global ecosystems, or both.
Can you be specific and not general?
Increased temperature alone doesn’t change much about gradients.
Increased humidity means energy imbalances can more readily be resolved by latent heat meaning, as indeed Manabe theorized decades ago, reduced temperature variability and reduced kinetic energy.
These risks cannot be quantified at this time
It would be progress if you could even identify them, much less quantify them.
and certainly wouldn’t (IMO) justify dramatic restructuring of the world’s economic structure. But if it’s possible to transfer away from fossil fuels without impacting energy prices or availability it would certainly be a good idea.
Indeed. Most don’t care about the source of their energy.
They do care about the cost, availability, and reliability.
Right now, the winner in those three categories is natural gas, which is a compromise win for everyone.
However, given demographics, it probably irrelevant.
But that’s what governments are best at: solving non-problems and leaving future generations to fix unintended consequences.