It's true that the models predict positive feedbacks. But in the real world, there are both positive and negative feedbacks. And the environment is a very complicated system on which it is very difficult to perform experiments. Therefore it is very difficult to tighten down your variables to the point where you can make accurate predictions. The current models cannot replicate the temperature movements of the past. Add that to the reasons that these models are not valid. But most of all...., see below.
It isn't as simple as simply looking at a tube of co2 and observing that the co2 absorbs a certain wavelength of energy. Everyone gets that. We all agree co2 is a greenhouse gas.
The earth is a complex system. https://en.wikipedia.org/wiki/Complex_system
Even wikipedia is willing to admit that it is very difficult to model this type of system, and that climate is a complex system. The models themselves are models on top of models. Which makes for extremely poor statistical validity.
But complex systems are complex. How do you model the risk an a meteor hitting the earth? How do you predict changes in insolation? How do you model changes in technology that make thorium the dominant source of energy?
I'm not saying co2 doesn't warm the earth, it does. But the runaway temperatures are modeled on those positive feedbacks, not on co2. Such things have never been observed in the past and have never been demonstrated experimentally. I'll believe it when there is evidence. These guys have made fake prediction after fake prediction. If they want to be taken seriously they should stop worrying about PR and produce real evidence that they understand the climate and aren't jut climate activists like James Hansen and Michael Mann with his fake hockey stick.
It's old news now, but the Copenhagen Consensus is just absolutely compelling. If you want to help people, climate change just isn't your bag. Millions of people are dying from indoor cooking fires, lack of gatorade, and lack of clean water. Deal with that stuff, you can save lives.