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