A projection is.
In my definition, it is "if I have x, y, z, and it continues on path q, I can project that it will continue to do so with a given accuracy". But as soon as I open my big fat mouth and say that "q will be such", I've changed from a projection of a model to a prediction. And when ALL of those predictions are wrong and revised.
That's where I think you're mistaken; they don't say, "q will be such", they state something more like, "if q continues to be such, we expect ___ with an X% level of confidence" (ya know, like scientists tend to do).
I found this IPCC glossary:
- Climate prediction
A climate prediction or climate forecast is the result of an attempt to produce a most likely description or estimate of the actual evolution of the climate in the future, e.g. at seasonal, interannual or long-term time scales. See also: Climate projection and Climate (change) scenario.
- Climate projection
A projection of the response of the climate system to emission or concentration scenarios of greenhouse gases and aerosols, or radiative forcing scenarios, often based upon simulations by climate models. Climate projections are distinguished from climate predictions in order to emphasise that climate projections depend upon the emission/concentration/ radiative forcing scenario used, which are based on assumptions, concerning, e.g., future socio-economic and technological developments, that may or may not be realised, and are therefore subject to substantial uncertainty.
Finally, the IPCC projections are criticized for being, if anything, too conservative in their projections. Time and time again they've said X in Y years and in Y - Z years X is seen to be having an effect. And when something stupid does come out (Himalayan glaciers melting in 30 years), they correct it. Ya know, like scientists do.
Also, don't confuse media headlines with IPCC projections, just like you can't expect to see realistic scenes of IT in movies.
And please, check out the link a few posts above that points to the Ars Technica story where the comp sci prof has a look at the models - he was impressed - they're pretty good. Or, "all models are wrong, some are useful" and climate models are useful.