Just to be clear, I neither deny nor affirm that the climate changes, and that humans may be a contributing factor in that change, though there is no factual basis I have seen to claim they the dominant factor. I just have no confidence at all in the currently-fashionable models, since they cannot pass the test I described, and believe it is therefore idiotic to base sweeping policy decisions on them. So much of the "Scientific community" that believes otherwise are either gadfly attention whores like the physicist Dr. Kaku with no more climatology credentials than Joe Bag-o'-donuts, meteorologists whose idea of 'Long-term' is one year, and actual climatologists whose livelihood is dependent on following the government and special-interest grant money to substantiate AGC that the term "Consensus" as applied to them is as silly as claiming Galileo was wrong and the Church right, because everybody in the Church power structure thought he was wrong.
Geological and Paleological science, before the current scramble for grants to find AGC overwhelmed any actual dispassionate inquiry, indicated that the climate has swung wildly back and forth in the deep past, often in extremely short timeframes between much warmer and much colder than now, possibly in as short as a decade. It also showed there has been a quite anomalous period of stability for about the last 10,000 years, during which the shifts like the Early Medieval Warming Period and the Little Ice Age were modest blips compared to the climate swings prior to the period of stability. This untoward stability allowed Mankind to get a foothold, engage in reasonably stable agriculture, and therefore explode across the planet.
One completely unexamined possibility is that worldwide human activity has actually amounted to a buffering or moderating influence on those wild swings, though realistically I expect it is really due to much more powerful factors like vulcanism and astrophysical 'Events' being possibly less prevalent in that ten-millennia window. The one thing the geological record does tell us for sure is that this Goldilocks period cannot last forever, and is likely to change suddenly and drastically at some completely unpredictable point in the future, with little or no forewarning...just hopefully not the immediate future.
I have zero confidence that the grant-funded models are of any value as applied to AGC, and will be of even less value should we return to the chaotic climate swings of the geological past.