Picking 1970 as a starting point was for a long time a common warmist (a believer in global warming , a scientist in this case) “cherry-pick”, because that was essentially at the bottom of the 1940-1975 cooling off period. By starting the period under consideration as a low point, everything is higher afterward, which makes it look perhaps worse than it really is. Of course it did get warmer, after the bottom of the cooling period. They used to throw in “since 1970” as being when all kinds of warming happened. Duh. Good thing, too!
Same thing about 1800, when they use that year (the BEST study did, and they were wrong to do that), because that was the end of the LIA when the world was going to warm up. And it is a good thing it did warm up!
We are “only” 210 or so years after the end of the LIA. To put that into paleoclimate perspective, the Younger-Dryas (Y-D) stadial began about 12,900 years ago. A stadial was/is a cool period, essentially was an ice age. The Y-D was the last real ice age. Its onset was VERY abrupt. It began over a period of about 0-200 years. No one knows yet how short a time it took. Greenland’s temperatures dropped by about 12 FULL degrees C, mostly right at the beginning. The Earth entered a new ice age, which it was not to come out of for 1200 years.
What we all think of as a stable temperature for X many thousands or millions of years simply didn’t happen. It is in our imaginations. Since the beginning of the Younger-Dryas the Earth has been in the Holocene, most of it much a much warmer period., certainly no ice age. Much of the era time was the Holocene Climatic Optimum (HCO), from 9,000 BP to 5,000 BP. Continue reading
The late archeologist Steve J Gould well into his career came up with a twist on evolution that was termed “punctuated evolution” (PE). PE was the first real acknowledgement that uniformitarianism was not the only principle at work in the earth sciences and biology. There was just so much evidence that something other than slow, incremental mutations and slow, incremental erosion, that sooner or later someone was going to have to bring in the sudden bursts and extinctions into the mix. Gould was the guy who did it, and I give him credit for doing it.
But, like all changes that come from within, PE was only a half step, a conservative step, one that had to be limited in its scope in order to be at all acceptable in his field. Evolution itself came from without. Alfred Wallace was not an academic, and if he hadn’t written Charles Darwin about his ideas about natural selection, Darwin might never have gotten around to publishing his ideas. Literally. Darwin knew it was too big a sea change and was trepidatious about putting his ideas out there. Without Wallace’s full conclusions about natural selection, one has to wonder what timid half step Darwin might have taken, if and when he would have gotten around to publishing anything.
But evolution or punctuated evolution, there is still a lot more evidence out there that something happened along the way that interrupted, not only natural selection, but the flow of human history. It may not even be a coincidence that the very demarcation between history and pre-history is laid out at the same time as the extinction of the mammoths and other megafauna in North America and the extinction of full-sized mammoths everywhere. But whatever it was, it was more extreme – in the time of man – than what is covered by Gould’s modification to Darwin’s theory. Mankind’s development did not stop with the advent of homo sapiens sapiens. at the individual level. Once sapiens began collecting in units larger than matings, his real devlopment took off.
So, more than punctuated evolution, as regards the development of h. sapiens sapiens. , there was the development of homo civilus. And it didn’t happen only once, unless I miss my mark.