More complex models incorporating other known factors, within the entire range of their uncertainty levels, show the same thing.
There are levels of skepticism. While I broadly agree with your points, the scientific issue comes down to one question and the political issue to another.
The scientific question is: how well do non-physical models allow us to predict in detail the response of a complex non-linear system like the climate to an additional 0.3% forcing?
The political question is: given that the uncontroversial answer to the scientific question is "not very well", what is the best policy approach to the risks presented?
My problem, as a computational physicist, is that the "scientific consensus" that supposedly exists seems to me to radically over-state the predictive power of non-physical climate models, and I am deeply concerned that as the supposed "hiatus" continues (http://www.tjradcliffe.com/?p=1460) the falsity of the over-stated claims will be used to attack science as such.
My problem, as a citizen, is that the political question has become parasitized by radical nut-jobs who would rather fight almost-irrelevant pipelines than promote nuclear power, research geo-engineering, or implement carbon taxes. The latter, especially, has proven to be an effective policy tool in reducing CO2 emissions (http://www.theglobeandmail.com/globe-debate/the-insidious-truth-about-bcs-carbon-tax-it-works/article19512237/) and anyone who cares about reducing corporate and personal income taxes ought to be fully on-side with it.
Yet the best we could get in Canada from Greenpeace in 2008 was "qualified support" for the Liberal's proposed tax shift and we've heard almost nothing from the since. Why aren't they shouting from the rooftops that we could reduce personal and corporate taxes by taxing carbon? What better argument could their be for promoting and making permanently sustainable a carbon tax?
The whole "science is settled" nonsense is an attempt to shut down legitimate concerns about the predictive utility of non-physical models of a non-linear system that are routinely found to be wrong (http://www.theguardian.com/science/2014/jan/01/climate-change-models-underestimate-likely-temperature-rise-report-shows).
And yeah, I know what the "direction" of the error is in most cases, but "better" and "worse" are not scientific terms, they are political terms. "More accurate" and "less accurate" are scientific terms, and a steady stream of news stories over the past decade has repeatedly touted the poor accuracy of GCMs.
Only in climate science are the conclusions of a model said to be more likely when the model is found to be wrong, yet that is what we routinely see: "climate models got near-term warming completely wrong so they are more likely than not correct about century-scale warming." But because climate is non-linear, it would be clearly and obviously anti-science and incorrect to claim that because the near-term error is one direction the long-term error must be in the same direction. There is simply no justification for that claim (nor the counter-claim, either, as Denialsts want us to assume.)
But the "science is settled" belief means that one can be a promoter of effective carbon tax policy, a promoter of building nuclear power plants and doing research in to geo-engineering (because really, if climate change could be a civilization-ending phenomena you've have to be utterly evil to not promote geo-engineering research, just in case) and still be an outcast to Warmists because you don't support the false belief that GCMs are very predictively useful.