I am not a climate scientist (but I understand the science)

The difference between pure climate science, using equations to work out the heat and IR balances etc, and what happens at each level of the atmosphere with the heat hitting the molecules in and out, and simple statistics which is far easier to follow. It is very possible to apply basic statistical rules without knowing any advanced methods, as if you have a complex system with innumerable inputs and measuring difficulties, you are still not applying advanced science as in high level equations, just pretty basic stuff with a heap of data.

The same rules apply however many variables you are working with, and the one about running a system forwards and the error margin widening over time is something you learn pretty early in the courses, and one similar example is the motion of a jet of water as the actual surface pattern is so complex it is virtually impossible to model. And not as complex as the climate. The nature of running complex non-linear models forwards itself is a false belief as they are attempting to carry out the impossible. The false positives they get are because within the chaos you have some basic cycles which can be predicted as they are linear- the ice age pattern repeats like clockwork as it is based on the same mechanisms which allow exact predictions of planetary bodies. But the rest of it- adding different gases etc is not based on the cyclic motion of planets but letting something with no physical boundaries into a moving stream of air with countless wind systems moving it around in ways the forecasters get wrong each day as often as they get right. But by looking at the correct elements of the models based on planetary movements they pretend it means every other random element can be predicted almost as well. Therefore you need the very least knowledge of climate science to work out the falsehood of models as it is based on basic rules of statistics.

Break down the data into individual items, then start putting it back together. This is little different in accounts or statistics. Then look at the results. You really don't need to be a climate scientist who can explain all the phenomena with causes and effects to see their quality. If it doesn't follow the basic rules of statistics, accounting or logic then it's almost certainly wrong. Just because someone's an expert doesn't make them perfect, and once a mistake is made and persists then everything above it will be based on it. That is why the climate models, which cannot work for the future as they break the rules of logic and science equally, must be void, and you don't need any qualifications to work it out and demonstrate it.