Why trust climate models? It’s a matter of simple science

While pondering Mike’s latest diversion, all of which seem as though intended to help contrarians feel secure about their crazy-making
rather then to encourage any sort of rational evaluation of science and it’s down to Earth lessons, I came across this most excellent article.

Why trust climate models? It’s a matter of simple science How climate scientists test, test again, and use their simulation tools. by Scott K. Johnson - Sept 5 2013, http://arstechnica.com/science/2013/09/why-trust-climate-models-its-a-matter-of-simple-science/ Talk to someone who rejects the conclusions of climate science and you’ll likely hear some variation of the following: “That’s all based on models, and you can make a model say anything you want." Often, they'll suggest the models don't even have a solid foundation of data to work with—garbage in, garbage out, as the old programming adage goes. But how many of us (anywhere on the opinion spectrum) really know enough about what goes into a climate model to judge what comes out? Climate models are used to generate projections showing the consequences of various courses of action, so they are relevant to discussions about public policy. Of course, being relevant to public policy also makes a thing vulnerable to the indiscriminate cannons on the foul battlefield of politics. Skepticism is certainly not an unreasonable response when first exposed to the concept of a climate model. But skepticism means examining the evidence before making up one’s mind. If anyone has scrutinized the workings of climate models, it’s climate scientists—and they are confident that, just as in other fields, their models are useful scientific tools. It’s a model, just not the fierce kind Climate models are, at heart, giant bundles of equations—mathematical representations of everything we’ve learned about the climate system. Equations for the physics of absorbing energy from the Sun’s radiation. Equations for atmospheric and oceanic circulation. Equations for chemical cycles. Equations for the growth of vegetation. Some of these equations are simple physical laws, but some are empirical approximations of processes that occur at a scale too small to be simulated directly. ...
That's just his warm up, it's a 4,600 word long information packed article. Worth the read if you're interested in a better understanding of the place of climate models within the science and how those models work. {I tip my hat to Sou at http://HotWhopper.com for pointing me to Scott K. Johnson's article}

It is not a matter of trust.
It is a matter of 7,000,000,000 people not having a spare planet.
In fact if we had a spare planet we could not get many people there anyway. Suppose Mars was perfectly inhabitable. How many people could we move?
So the objective should be to make more and more trustable models to understand what is going on no matter what.