where can we find a completely accurate (or even reasonably accurate) climate model?
Model's aren't completely accurate. If you're asking for one, you've got an agenda that is not science based.
Where do you find a reasonably accurate one? You could start at NASA, NOAA, HadCRU, DOE, NCAR, or the Canadian Centre for Climate Modelling and Analysis, CERFACS (France) for some well known General Circulation Models.
Point is, the science is not "settled", unless everyone is agreeing on the mere fact that climate does change over time (which, seriously, no one credibly argues against).
There are things that are settled. The solar system is heliocentric. Human activity is probably responsible for most of the current warming. Plate tectonics causes continental drift.
what is the rate of change, and is is accurate enough to take action against?
Over the past decade or so, it ranges between 0.5 and 1 W/m st the top of atmosphere. It's accurate enough to know that reducing emissions alone almost certainly isn't going to avoid the 3C change that is considered dangerous. (If you're not concerned with dropping biodiversity too much).
If we overestimate, then our best efforts may well over-correct, and we touch off a new ice age.
I doubt it. Even above the tropopause sulphate aerosols last years and not decades. Lower technology methods such as increasing cloud reflectivity and tropospheric sulphate aerosols stop having an effect the week following the one you stop doing it.
Those are the methods discussed in TFA.
As it is, there's still too much slop factor, and the degree of confidence isn't high enough across the spectrum of scientists.
Big call. How much "slop factor" is there, what degree of confidence would be high enough across the spectrum of scientists?
Why do you need to be across the spectrum of scientists?
Wouldn't reasonable expectation based on a vast majority opinion be sufficient to act?
Was it primarily due to politics, culture, technology, medical/scientific knowledge... what? Most of what I just listed has bugger-all to do with the climate.
I think that you're mistaken if you think that politics, culture, technology, medicine and scientific knowledge are independent of climate. There are wars in the Norther of Africa now that are probably strongly affected by nomadic peoples having to wander into non-traditional lands because of droughts probably attributable to the anthropogenic part of climate change.
Wars affect politics and culture directly, and indirectly technology and scientific knowledge. Medicine? There are many medical effect of climate change that are behind studied.
1) climate does change, and trying to keep everything just like it is in the 1980s (or whenever) may do more damage than just letting it cycle naturally.
Naturally? Did you know that burning fossil fuels releases greenhouse gasses, and that greenhouse gasses cause the greenhouse effect?
There's nothing natural about what the climate is doing now, and neither is it "cycling".
before your investigations turn into actions, you'd damned well better know for certain what you are doing - making mistakes on a global level will have global consequences, and will last for a very long, long time.
If the action is introduce additional sulphate aerosols into the stratosphere (or upper troposphere), how long is this "very long long time?". Seven years? Eight?