How james hansen and michael mann destroyed climate science the deplorable climate science blog gas in stomach

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Nevertheless, I would like to make one point: I disagree with Tom when he states that the IPCC 1990 graphic was drawn by hand; on the contrary, I think it was drawn with the software available at that time. And I remember the times I had to fight against the “intelligence” built in some of those programs, having to change my data tables so that the graphics were rigth. The thing was, many programs, when drawing _certain_ (not all!) types of curves, applied the point to the _middle_ of the next interval between the x-axis coordinates, and in other cases they plotted the points calculated for the middle points on the _left_ limit of each interval. There were no established “rules” for this “intelligent” behaviour, and Excel was particularly bad in this respect.

Now, it seems, from the inflections of the curve in the IPCC1990 graphic, that the original data were at 50 years intervals. What Tom has done was to displace the graphic by 50 years (ex.: put its 1940 value on the 1990 abscissa). Most probably, the original IPCC1990 plot was already affected by this error, but one will never know unless we find the original data.

I also guess that the differences in length of the horizontal scale units are due to rounding errors of the sofware of that time and on top of them the poor resolution (and software) of the printers: I also have some bad memories of correcting this kind of ugliness in my graphics and one can easily find many examples browising the scientific journals of that time (mainly, before the fear of the year 2000 bug).

According to ice core records, the last millennium 1000AD – 2000AD has been the coldest millennium of our current Holocene interglacial. This point is more fully illustrated with ice core records on a millennial basis back to the Eemian period here:

Our current, warm, congenial Holocene interglacial, although cooler than the Eemian interglacial 120,000 years ago, has been the enabler of mankind’s civilisation for the last 10,000 years, spanning from mankind’s earliest farming to the most recent technologies.

Viewing the current Holocene interglacial on a millennial basis is rational. But sadly it seems that, driven by the need to continually support the Catastrophic Anthropogenic Global Warming hypothesis / religion Climate alarmists irrationally examine the temperature record at too fine a scale, weather event by weather event, month by month, or year by year.

From the broader perspective, each of the notable high points in the current 11,000 year Holocene temperature record, (Holocene Climate Optimum – Minoan – Roman – Medieval – Modern), have been progressively colder than the previous high point.

The ice core records from Greenland for its first 7-8000 years, the early Holocene, shows, virtually flat temperatures, an average drop of only ~0.007 °C per millennium, including its early high point known as the “climate optimum”. But the more recent Holocene, since a “tipping point” at around 1000BC, 3000 years ago, has seen temperature fall at about 20 times that earlier rate at about 0.14 °C per millennium .

The world should now fear the real and detrimental effects of cooling, rather than being hysterical about limited, beneficial or probably now non-existent further warming. Warmer times are times of success and prosperity for man-kind and for the biosphere. For example during the Roman warm period the climate was warmer and wetter so that the Northern Sahara was the breadbasket of the Roman empire.

But the coming end of the present Holocene interglacial will eventually again result in a mile high ice sheet over much of the Northern hemisphere. As the Holocene epoch is already about 11,000 years old, the reversion to a true ice age is becoming overdue.