If that seems magical to you, then most of the world should seem like magic rather than science. We can predict all sorts of things over long time scales that we can't predict over short time scales, and we do it all the time. We can't predict turbulence or the exact way that steam will rise from a hot cup of tea, but we can predict the amount of steam and the average speed of its rising.
And if you think that you have any sorts of technical chops, familiarize yourself with things like the Lorentz attractor, for which we can not predict exact trajectories, but we can predict where the two attractors are.
https://en.wikipedia.org/wiki/Wishful_thinking
https://en.wikipedia.org/wiki/Appeal_to_consequences
Life (including human life ant its apurtenances) is transformative. It maximizes entropy generation and energy throughput. It's dramatically affected Earth's climate several times in the past, and many of the life-forms responsible for those dramatic effects didn't survive them.
Still other things like e.g anesthesia is also magic to me, but I know for a fact that it works.
What bugs me about GW research is lack of focus on mitigating GW, other than by cutting greenhouse gasses (ain't gonna happen) and especially things like this:
http://www.forbes.com/sites/jamestaylor/2011/11/23/climatega...
Lots of non-sceptics would tell me that some scientists would break ranks if they found an issue, but those emails suggests that such attempts would be prevented. Considering how much money is given to these scientists by the government and how much their funding would be cut if it was found out to be a none issue, I can't consider them impartial.
So it boils down to a lack of trusts in scientists and an inability to interprent the data.