"So what data from the last century or so supports any supposition that prediction of future climate states is in any way possible, whether exactly possible or even vaguelly possible? "
That isn't the point of my post. I have no position on climate change.

1. I didn't say data supported predictions. That was a separate point I brought up. In another section of the report they talked about carbon cycle and data they had collected from Vostok. This data makes it clear that humans have affected climate.

2. The climate models are already making predictions. The question is how accurate are they. Currently, they don't know how accurate they are (for the reasons cited). But it's not fair to say that they know nothing.