[adrienthebo]

The greenhouse effect is due to radiation being trapped by the environment, atmospheric or otherwise - not the increased CO2. And while greenhouses may have artificially increased CO2 to improve plant growth it's accompanied with nitrogen fertilizer. The global increase in CO2 will only see a minor increase in plant growth but will be capped by limited nitrogen, and the hotter environment and associated increase in water evaporation will lead to reduced plant growth.

[seibelj]

Not if increased water evaporation leads to increased cloud cover leads to increased rainfall. We don’t know what will happen, it’s simply too complex to model accurately.

[adrienthebo]

"We don't know what will happen" is a specious reply because the models we do have are continuously improving, have been proven quite accurate so far, and backtesting continues to refine the behavior. This isn't a matter of having no idea what'll happen; there'll always be uncertainty but when the models continue to be validated and keep pointing at potentially devastating scenarios then the prudent thing is to act now instead of hoping the models are wrong.

[seibelj]

What we can definitively say is that CO2 levels have increased dramatically since the industrial revolution, and their cause is humans burning fossil fuels. On the models themselves, if you look deeply at how they are created and how they are updated, they involve a ridiculous amount of "tuning" where basically they don't line up with historical records so they have to continually modify them with fudge factors.

I think the central problem is that the way they divide the atmosphere / oceans into 100km square grids is too large for local weather, but if they shrink the grids it takes way too long to run the simulations, so they are in a bind. I am of the opinion it's better not to risk increasing the amount of CO2 because we don't know what will happen. But I wouldn't consider any of our models even low-confidence. It is impossible to solve given how chaotic nature is, the number of variables, and how slow our super computers currently are.