A common critique of climate predictions is, "If weather model forecasts aren't reliable more than a week out, how can models predict climate decades in the future?" While weather and climate models are based on similar physics, they are not predicting the same thing. Weather forecasts look at the day-to-day changes on a local level, while climate predictions are focused on longer term processes and global or regional scales.  Subtle chaotic atmospheric variations make short-term weather forecasts difficult beyond 8-10 days. Climate models deal with the longer-term influences of the sun, oceans, land, and ice on the atmosphere.  Predicting a temperature at a particular place at a particular hour is a different problem than projecting an average temperature in a large region or over the entire globe and over a year, decade, or century.

The bottom line is that models have shown a reasonably consistent picture of warming and its causes.