Michael Mann’s hockey stick graph, which purported to show that global temperatures hummed along at virtually a flat rate until a recent, unprecedented uptick, has long been discredited as an artifact of either ineptitude or fraud. In fact, global temperatures have varied significantly throughout the Earth’s history, including the last 12,000 years.
But the U.N.’s Intergovernmental Panel on Climate Change apparently is trying to bring back the hockey stick. One of the IPCC’s 6th report reviewers reports, in translation from the German:
In the Middle Ages, it was similarly warm in Switzerland and other parts of Central Europe as it is today. The so-called Medieval Warm Period (MWP) is scientifically well documented in the region: Between 800 and 1300 A.D., many Alpine glaciers shrank dramatically and some were even shorter than today. The tree line shifted upward. Permafrost thawed in high alpine regions that are still firmly in the grip of ice today. Warm temperatures are also clearly evidenced by tree rings, pollen, chironomid fossils, and other geological reconstruction methods.
It had long been assumed that the medieval warmth might be a regional, North Atlantic phenomenon. However, this has not been confirmed, because the warm phase also occurred in many other regions of the world, for example, on the Antarctic Peninsula, in the Andes, in North America, in the Arctic, in the Mediterranean, in East Africa, China and New Zealand.
Together with professional colleagues, we at Die kalte Sonne have evaluated many hundreds of case studies from around the world in recent years and published the syntheses continent by continent in peer-reviewed journals.
Three of the publications have been cited by the Intergovernmental Panel on Climate Change (IPCC) in its recently published 6th Assessment of the Climate report. The medieval warmth was then followed globally by a precipitous drop in temperature. During the Little Ice Age, 1450-1850, the climate cooled to the coldest temperature level of the entire last ten thousand years.
This is what I would call the conventional narrative of global temperatures in the post-Ice Age millennia. But the IPCC’s 6th report undertakes some revisionist history:
In the new IPCC report, one will unfortunately look for this information in vain. In it one elevates one’s own view of the climate history of the last thousand years. In the summary intended for politicians, a controversial temperature curve is prominently displayed right at the beginning, giving the impression that there were only minimal pre-industrial climate changes in the last two millennia. With the onset of industrialization around 1850, the curve then rockets upward by more than one degree. This mode of representation is also known as the “hockey stick”: The climatically supposedly uneventful pre-industrial period forms the straight shaft of the stick, and at its end, with rapid modern warming, comes the upward blade of the hockey stick. It is therefore a déjà vu, an unnecessary one. The 3rd Assessment of the Climate Report of 2001 already contained a similar field hockey stick pattern, intended to fool politicians into thinking that today’s warming was unprecedented and therefore entirely man-made.
That was before Michael Mann’s graph was decisively refuted.
In the last two decades, however, paleoclimatology has made great progress, and data have been diligently collected. From this, more realistic temperature developments were created, with a pronounced Medieval Warm Period and a later Little Ice Age.
All the more bitter now is the relapse into old hockey stick times. How could this happen? What were possible motivations behind the renewed distortion of climate history?
This German source traces the contamination to a Swiss university, but I think a more fundamental answer is that an enormous amount of money is at stake. If climate hysteria leads to a retooling of the world’s energy system, almost all of us will suffer a decline in our standard of living. Unreliable energy, heretofore a hallmark of the underdeveloped world, will come to Western Europe and the United States. Nearly everyone will suffer, but a tiny handful of “green” magnates will walk away with countless billions in profits.
This is why “green” activists are trying to bring back the long-discredited hockey stick.