You can never predict something as complex as the earth climate.

It's not a question of computing power: it's impossible to predict a complex system at all.

We can't even predict a simple double pendulum, now imagine a climate simulation: it's basicaly billions of double pendulums, all dependent one on another.

Even the smallest error in initial conditions or the models and even over a short period it will totaly diverge from what will actually happen on Earth.

This will be nothing other than a money sink. Invenst into clean tech, not these useless models that are incapable of predicting anything at all.

Eg how can you take in account a solar cycle which could change the energy that the Earth recieves more than any human made intervention/pollution?

You cannot. All of these models will fail totaly.

But politicians and the media love them for fear mongering, which is how the money gets pumped into this.