Honest question: How does anyone know what the temp was 10,000 years ago, even 1,000 years ago?
I'm with you. I don't put too much stock into what's called "proxy measurements", though I every now and then read about them. Michael Mann's fraudulent "hockey stick" was based on examining tree rings. If I remember the details correctly, there may actually be something to glean from that, except that they intentionally discarded the tree rings that suggested the Medieval Warm Period and Little Ice Age (to make the centuries before the Modern Warm Period look flat so that the MWP looked unprecedented).
And the graph I post is also from using proxy measurements, but from ice core samples in Greenland. I'm a bit --- well --- not so into that either. But what I like about it is that graph seems to correspond with what we know from written history about shorelines from the past 2 or 3 thousand years. Same with horrible climate problems from life in the cooling periods (lower crop yields, less regular precipitation, more deaths by plague) that we know from written history that happened.
For example, if you're a Bible geek, know that the Minoan Warm Period that began about 3,500 to 3,700 years ago and topped out about 3,000 to 3,100 years ago (top of the red hump to the left of the Roman Warm Period) pretty much corresponds to what we call the Era of Judges (Moses to Samuel). Before that Minoan Warm Period is a cooling downturn, and that's when the stories of major famines in Genesis occurred (Abraham and his nephew, Lot, having to separate because the land could no longer support them, later Jacob sending his sons to Egypt because of famine). Then during the Minoan Warm Period is when Moses wrote in the Torah what they should do with the excess crops (leave them for the poor and foreigner).
The entire New Testament was about things that occurred during the Roman Warm Period. I don't remember reading about famines then (because crop yields were higher, based on what we know from more recent warm periods in which there were more detailed histories written). Back then the Greek city Ephesus (think Paul's epistle Ephesians) was a port city. Now the ruins of the city are miles from the shoreline. The city didn't move. The shore did. That suggest that today the sea levels (and thus temps) aren't as high as they were during the Roman Warm Period. The are other non-Biblical shorelines (i.e. Pevensey Castle in the UK had boats dock to in during the Medieval Warm Period when the tide was high, but now it's a mile from the shore line.)
The settling of America was during the Little Ice Age. Think about all of the suffering from hunger and disease (i.e. Pilgrims, Washington's men, indigenous Americans). The same went on in the Old World (i.e. Black Plague in Europe and elsewhere, megadroughts in Africa -- perhaps a catalyst for the supply side of the black slave trade during those centuries).
And the whole time the Dims want us to hate on living in one of the warm periods when it's so easy to grow crops that the federal government literally pays some farmers to not grow food (most of the time it's ostensibly to keep farmers from oversupplying the food market, which would lower the food prices and put farmers out of business, though there are few other situations like to prevent erosion in some areas, etc.).