Chaotic dynamical system with long term prediction impossible. Yes.
I'm grimly delighted by the news that the thermohaline circulation in the North Atlantic appears to be shutting down. If it does, we're looking at a new Ice Age.
Which makes one wonder whether the warming we've had is simply the warming that occurs at the end of an interglacial period -- the ice ages all occurred with the continents in more or less their present positions, and one of the better hypotheses for their causation is just that: warming causing ice melt in the arctic decreases salinity in the North Atlantic, shutting down the Gulf Stream, heat not making it to the Arctic causes a sequence of cold winters in which the extra open water results in massive snowfalls on land and, within a decade the glaciers are back.
Which is why the correct reaction to the indisuptable fact that climate changes is not to chase a solution to a hypothesized cause, but to work on adaptation. All the money going to "decarbonizing" the energy economy should instead be going to ag research to find ways of growing food in more extreme climates (both hotter and colder, both drier and wetter), building massive greenhouses so food can be grown in any climate (the ChiComs are already doing this), and building water projects to move water from areas suddenly getting more rain to areas experiencing droughts (and they should be designed to work in both directions in case the effects reverse). Lots of nuclear plants would be nice, too, since we may need more energy to adapt.
